3-3-2 rule A method used to predict difficult intubation. A mouth opening of less than three fingers wide, a mandible length of less than three fingers wide, and a distance from hyoid bone to thyroid notch of less than two fingers wide indicate a possibly difficult airway.
6 Ps of musculoskeletal assessment Pain, Paralysis, Parasthesias, Pulselessness, Pallor, and Pressure.
6-feet rule A guideline to follow regarding the distance to place between oneself and a person who sneezes or coughs, to avoid exposure to germs.
abandonment Termination of care for the patient without giving the patient sufficient opportunity to find another suitable health care professional to take over his or her medical treatment.
abdomen The body cavity that contains the major organs of digestion and excretion. It is located below the diaphragm and above the pelvis.
abdominal aortic aneurysm (AAA) A sac or bulge in the wall of the abdominal portion of the aorta, resulting in weakening of that wall; it is considered life threatening if it ruptures.
abdominal thrust maneuver Abdominal thrusts performed to relieve a foreign body airway obstruction.
abduction Movement away from the midline of the body.
aberration A term used to describe the shape of the QRS complex in aberrantly conducted beats.
ABO system The commonly used blood classification system, based on the antigens present or absent in the blood.
abortion Expulsion of the fetus, from any cause, before the 20th week of gestation.
abrasion An injury in which a portion of the body is denuded of the epidermis by scraping or rubbing.
abruptio placenta A premature separation of the placenta from the wall of the uterus.
abscess A collection of pus in a sac, formed by necrotic tissues and an accumulation of white blood cells; the immune system creates the sac to prevent spread of the infection.
absence seizures The type of seizures characterized by a brief lapse of attention in which the patient may stare and not respond; formerly known as petit mal seizures.
absolute refractory period The early phase of cardiac repolarization, wherein the heart muscle cannot be stimulated to depolarize; also known as the effective refractory period.
absorption The process by which the molecules of a substance are moved from the site of entry or administration into systemic circulation; also refers to the process of foreign materials being deposited onto and moving into the skin; also refers to type of decontamination that is done with large pads that the hazardous materials team use to soak up liquid and remove it from the patient.
abuse Any form of maltreatment that results in harm or loss. Maltreatment may be physical, sexual, psychological, or financial/material.
acalculus cholecystitis Inflammation of the gallbladder without the presence of gallstones.
acceleration (a) The rate of change in velocity; speeding up.
access port A sealed hub on an administration set designed for sterile access to the IV fluid.
accessory muscles The muscles not normally used during normal breathing; include the sternocleidomastoid muscles of the neck, the chest pectoralis major muscles, and the abdominal muscles.
accountability system A method of accounting for all personnel at an emergency incident and ensuring that only personnel with specific assignments are permitted to work within the various zones.
acetabulum The depression on the lateral pelvis where its three component bones join, in which the femoral head fits snugly.
acetylcholine (ACh) A chemical neurotransmitter which servers as a mediator in both the sympathetic and parasympathetic nervous systems.
acetylcholinesterase The enzyme that causes muscle relaxation by helping to break down acetylcholine.
acholic stools Light, clay-colored stools indicative of liver failure.
acid Any molecule that can give up a hydrogen ion (H+), and therefore increases the concentration of hydrogen ions in a water solution.
acidosis A pathologic condition resulting from the accumulation of acids in the body (blood pH less than 7.35).
acoustic neuroma A slow-growing, benign tumor of the vestibular cochlear nerve that can lead to loss of hearing in the affected ear.
acquired immunity The immunity that occurs when the body is exposed to a foreign substance or disease and produces antibodies to the invading antigen.
acquired immunodeficiency syndrome (AIDS) The end-stage disease process caused by the human immunodeficiency virus (HIV); results in extreme vulnerability to numerous opportunistic bacterial, viral, and fungal infections that would not affect a person with an intact immune system.
acrocyanosis Cyanosis of the extremities due to a decrease in the amount of oxygen delivered to the extremities; the hands and feet turn blue because of narrowing (constriction) of small arterioles (tiny arteries) toward the end of the arms and legs.
acromioclavicular separation (AC separation) An injury caused by distraction of the clavicle away from the acromion process of the scapula.
acromion Lateral extension of the scapula that forms the highest point of the shoulder.
acromion process The tip of the shoulder and the site of attachment for both the clavicle and various shoulder muscles.
action potentials An electrochemical event where stimulation of a nearby cell could cause excitation of another cell.
activation Mediators of inflammation trigger the appearance of molecules known as selectins and integrins on the surfaces of endothelial cells and polymorphonuclear neutrophils, respectively.
active hyperemia The dilation of arterioles after transient arteriolar constriction, which allows influx of blood under increased pressure.
active metabolite A medication that has undergone biotransformation and is able to alter a cellular process or body function.
active shooter A gunman who has begun to fire on people and is still at large.
active transport A method used to move compounds across a cell membrane to create or maintain an imbalance of charges, usually against a concentration gradient and requiring the expenditure of energy.
activities of daily living (ADLs) The basic activities a person usually accomplishes during a normal day, such as eating, dressing, and washing.
acute abdomen A condition of sudden onset of pain within the abdomen, usually indicating peritonitis; demands immediate medical or surgical treatment.
acute angle-closure glaucoma (AACG) Increased intraocular pressure that leads to ocular pain and decreased visual acuity; sudden onset is a medical emergency.
acute chest syndrome A vasoocclusive crisis that can be associated with pneumonia; common signs and symptoms include chest pain, fever, and cough; associated with sickle cell disease.
acute coronary syndrome (ACS) Term used to describe any group of clinical symptoms consistent with acute myocardial ischemia.
acute dystonic reaction A syndrome that may occur in patients taking typical antipsychotic agents. The patient develops muscle spasms of the neck, face, and back within a few days of starting treatment with the drug.
acute gastroenteritis A family of conditions that revolve around a central theme of infection with fever, abdominal pain, diarrhea, nausea, and vomiting.
acute lung injury A condition in which lung tissue is damaged, characterized by hypoxemia, low lung volume, and pulmonary edema.
acute mountain sickness (AMS) An altitude illness characterized by headache plus at least one of the following: fatigue or weakness, gastrointestinal symptoms (nausea, vomiting or anorexia), dizziness or light-headedness, or difficulty sleeping.
acute myocardial infarction (AMI) A condition present when a period of cardiac ischemia caused by sudden narrowing or complete occlusion of a coronary artery leads to death (necrosis) of myocardial tissue.
acute radiation syndrome The clinical course that usually begins within hours of exposure to a radiation source. Symptoms include nausea, vomiting, diarrhea, fatigue, fever, and headache. The long-term symptoms are dose-related and are hematopoietic and gastrointestinal.
acute renal failure (ARF) A sudden decrease in filtration through the glomeruli.
acute splenic sequestration syndrome A condition in which red blood cells become trapped in the spleen, causing a dramatic fall in hemoglobin available in the circulation; usually occurs in infants or toddlers.
acute stress reaction Reaction to stress that occurs during a stressful situation.
Adam’s apple The firm prominence in the upper part of the larynx formed by the thyroid cartilage. It is more prominent in men than in women.
adaptation The temporary or permanent reduction of sensitivity to a particular stimulus.
adaptive (specific) defense Immunity; it targets specific pathogens and acts more slowly than innate defenses.
addisonian crisis Acute adrenal insufficiency.
adduction Movement toward the midline of the body.
adenoid The pharyngeal tonsil; located on the posterior nasopharyngeal wall.
adenosine triphosphate (ATP) The nucleotide involved in energy metabolism; used to store energy.
adhesion The attachment of polymorphonuclear neutrophils to endothelial cells, mediated by selectins and integrins.
adipose tissue Fat tissue that lies beneath the skin, between muscles, around the kidneys, behind the eyes, in certain abdominal membranes, on the heart’s surface, and around certain joints.
administration set Tubing that connects to the IV bag access port and the catheter to deliver IV fluid.
adnexa The surrounding structures and accessories of an organ; for the eye: the eyelids, lashes, lacrimal structures.
adolescents Persons who are 13 to 17 years of age.
adrenal cortex The outer layer of the adrenal gland; it produces hormones that are important in regulating the water and salt balance of the body.
adrenal glands Paired endocrine glands located on top of the kidneys that release adrenalin when stimulated by the sympathetic nervous system; each adrenal gland consists of an inner adrenal medulla and an adrenal cortex.
adrenal medulla The inner part of the adrenal glands that produces catecholamines (epinephrine and norepinephrine).
adrenaline Hormone with alpha and beta sympathomimetic properties, produced by the adrenal glands that mediates the “fight-or-flight” response of the sympathetic nervous system; also called epinephrine.
adrenergic receptor A type of receptor that is associated with the sympathetic nerves and that is stimulated by epinephrine and norepinephrine; activation causes a sympathetic response.
adrenocorticotropic hormone (ACTH) Hormone that targets the adrenal cortex to secrete cortisol (a glucocorticoid).
Adult Protective Services (APS) Organizations that investigate cases involving abuse and neglect and provide case management services in some cases.
advance directive A written document or oral statement that expresses the wants, needs, and desires of a patient in reference to future medical care; examples include living wills, do not resuscitate (DNR) orders, and organ donation choices.
adventitious A type of breath sound that occurs in addition to the normal breath sounds; examples are crackles and wheezes.
adventitious breath sounds Abnormal breath sounds such as wheezes, rhonchi, rales, stridor, and pleural friction rubs.
adverse reaction/side effect Abnormal or harmful effect to an organism caused by exposure to a chemical. It is indicated by some result such as death, a change in food or water consumption, altered body and organ weights, altered enzyme levels, or visible illness.
aerobic metabolism Metabolism that can proceed only in the presence of oxygen.
affect The outward expression of a person’s inner feelings (happy, sad, angry, fearful, withdrawn).
afferent arteriole The structure in the kidney that supplies blood to the glomerulus.
afferent nerves Nerves that send information to the brain.
affinity The ability of a medication to bind with a particular receptor site.
after-action report (AAR) The official internal report of the entire event, such as a disaster, which should contain the facts of the incident reflected in a chronologic, accurate manner.
afterdrop Continued fall in core temperature after a victim of hypothermia has been removed from a cold environment, due at least in part to the return of cold blood from the body surface to the body core.
after-image The perception of a stimuli is still present after the stimuli is removed.
afterload The pressure in the aorta against which the left ventricle must pump blood; increasing this can decrease cardiac output.
agnosia Inability to connect an object with its correct name.
agonal Pertaining to the period of dying.
agonal gasps Slow, gasping respirations, indicating life-threatening cerebral injury or ischemia.
agonal rhythm A cardiac dysrhythmia seen just before the heart stops altogether; essentially asystole with occasional QRS complexes that are not associated with cardiac output.
agonist A substance that mimics the actions of a specific neurotransmitter or hormone by binding to the specific receptor of the naturally occurring substance; triggers a response, producing some kind of action or biologic effect.
agonist medications The group of medications that initiates or alters a cellular activity by attaching to receptor sites, prompting a cellular response.
agoraphobia Literally, “fear of the marketplace”; fear of entering a public place from which escape may be impeded.
agranulocytes Leukocytes that lack granules.
air ambulances Fixed-wing aircraft and helicopters that have been modified for medical care; used to evacuate and transport patients with life-threatening injuries to treatment facilities.
air embolism The presence of air in the venous circulation, which forms a gas bubble that can block the outflow of blood from the right ventricle to the lung; can lead to cardiac arrest, shock, or other life-threatening complications.
airborne transmission The transmission of an organism or infectious agent by inhalation of small particles that become aerosolized when the infected person coughs, sneezes, talks, or exhales; particles remain suspended in this vapor and can be carried a short distance, usually 3’ to 6’.
albumins The smallest of plasma proteins; they make up around 60% of these proteins by weight.
alcoholic ketoacidosis The metabolic acidotic state that manifests because of the inadequate nutritional habits associated with chronic alcohol abuse. The liver and body experience inadequate fuel reserves of glycogen and, thus, have to switch to fatty acid metabolism.
alcoholism A state of physical and psychological addiction to ethanol.
aldosterone One of the two main hormones responsible for adjustments to the final composition of urine; increases the rate of active reabsorption of sodium and chloride ions into the blood and decreases reabsorption of potassium.
alert and oriented (A × O) A determination made when assessing mental status by looking at whether the patient is oriented to four elements: person, place, time, and the event itself. Each element provides information about different aspects of the patient’s memory.
alkalosis A pathologic condition resulting from the accumulation of bases in the body (blood pH greater than 7.45).
alleles Variant forms of a gene, which can be identical or slightly different in DNA sequence.
allergen A substance that causes a hypersensitivity reaction or an allergic reaction; also referred to as an antigen.
allergic reaction An abnormal immune response the body develops when reexposed to a substance or allergen.
allergy A hypersensitivity reaction to the presence of an agent (allergen) that is intrinsically harmless.
all-hazards approach The act of conducting comprehensive preplanning that will apply to any disaster.
alpha Type of energy that is emitted from a strong radiologic source; it is the least harmful penetrating type of radiation and cannot travel fast or through most objects.
alpha cells Cells located in the islets of Langerhans that secrete glucagon.
alpha effects Stimulation of alpha receptors that results in vasoconstriction.
alternative powered vehicles A vehicle that uses fuels other than petroleum or a combination of petroleum and another fuel for power.
alternative time sampling Time parameters that are set during a research project.
altitude illnesses Conditions caused by the effects from hypobaric (low atmospheric pressure) hypoxia on the central nervous system and pulmonary systems as a result of unacclimatized people ascending to altitude; range from acute mountain sickness (AMS) to high-altitude cerebral edema (HACE) and high-altitude pulmonary edema (HAPE).
alveolar ducts Ducts formed from division of the respiratory bronchioles in the lower airway; each duct ends in clusters known as alveoli.
alveolar minute volume (VA) The amount of air that actually reaches the alveoli per minute and participates in gas exchange.
alveolar ridges The ridges between the teeth that are covered with thickened connective tissue and epithelium.
alveolar volume Volume of inhaled air that reaches the alveoli and participates in gas exchange; equal to tidal volume minus dead space volume and is approximately 350 mL in an average adult; also called alveolar ventilation.
alveoli The air sacs of the lungs in which the exchange of oxygen and carbon dioxide takes place (singular, alveolus). In the context of facial anatomy, small pits or cavities, such as the sockets for the teeth.
alveolocapillary membrane The very thin membrane, consisting of only one cell layer, that lies between the alveolus and capillary, through which respiratory exchange between the alveolus and the blood vessels occurs.
Alzheimer disease A progressive organic condition in which neurons in the brain die, causing dementia.
amblyopia Lazy eye; the eyes may be oriented correctly but one fails to send adequate signals to the vision centers, also causing a loss of depth perception and poor-quality images.
amenorrhea Absence of menstruation.
ammonium nitrate A commonly used industrial-grade fertilizer that is not in itself dangerous to handle or transport, but when mixed with fuel and other components, forms an extremely explosive compound.
amniotic fluid A clear, slightly yellowish liquid that surrounds the fetus during pregnancy; contained in the amniotic sac.
amniotic fluid embolism An extremely rare, life-threatening condition that occurs when amniotic fluid and fetal cells enter the pregnant woman’s pulmonary and circulatory system through the placenta via the umbilical veins, causing an exaggerated allergic response from the woman’s body.
amniotic sac The fluid-filled, baglike membrane in which the fetus develops.
amphetamines A class of drugs that increase alertness and excitation (stimulants); includes methamphetamine (crank or ice), methylenedioxyamphetamine (MDA, Adam), and methylenedioxymethamphetamine (MDMA, Eve, ecstasy).
ampules Small glass containers that are sealed and the contents sterilized.
amputation An injury in which part of the body is completely severed.
amyotrophic lateral sclerosis (ALS) ALS, also known as Lou Gehrig disease, strikes the voluntary motor neurons, causing their death. The disease is characterized by fatigue and general weakness of muscle groups; eventually the patient becomes unable to walk, eat, or speak.
anabolism The synthesis of larger molecules from smaller ones.
anaerobic metabolism Metabolism that takes place in the absence of oxygen; the principal byproduct is lactic acid.
anal fissures Linear tears to the mucosal lining in and near the anus, possibly caused by the passage of large, hard stools; a cause of lower GI bleeding.
anaphylactic shock A severe hypersensitivity reaction that involves bronchoconstriction and cardiovascular collapse.
anaphylactoid reaction An extreme allergic response that does not involve IgE antibody mediation. The exact mechanism is unknown, but an anaphylactoid event may occur without the patient being previously exposed to the offending agent.
anaphylaxis An extreme systemic form of an allergic reaction involving two or more body systems.
anatomic position The position of reference in which the patient stands facing you, arms at the side, with the palms of the hands forward.
anatomy The study of the structure of an organism and its parts.
anchoring bias Occurs when an initial reference point distorts your estimates.
androgens Male sex hormones mostly produced by the testicular interstitial cells, and which regulate body changes associated with sexual development (puberty), including growth spurts, deepening of the voice, growth of facial and pubic hair, and muscle growth and strength.
anemia A lower than normal hemoglobin or erythrocyte level.
anesthesia Lack of feeling within a body part.
aneurysm A swelling or enlargement of part of a blood vessel, resulting from weakening of the vessel wall.
angina pectoris The sudden pain from myocardial ischemia, caused by diminished circulation to the cardiac muscle. The pain is usually substernal and often radiates to the arms, jaw, or abdomen and usually lasts 3 to 5 minutes and disappears with rest.
angioedema A vascular reaction that may have an allergic cause and may result in profound swelling of the tongue and lips.
angiogenesis The growth of new blood vessels.
angle of impact The angle at which an object hits another; this characterizes the force vectors involved and has a bearing on patterns of energy dissipation.
angle of Louis Prominence on the sternum that lies opposite the second intercostal space.
angulation The presence of an abnormal angle or bend in an extremity.
anion An ion that contains an overall negative charge.
anisocoria Unequal pupils with a greater than 1-mm difference.
anorexia nervosa An eating disorder in which a person diets by exerting extraordinary control over his or her eating, and loses weight to the point of jeopardizing his or her health and life.
anoxia An absence of oxygen.
antagonist A molecule that blocks the ability of a given chemical to bind to its receptor, preventing a biologic response.
antagonist medications The group of medications that prevent endogenous or exogenous agonist chemicals from reaching cell receptor sites and initiating or altering a particular cellular activity.
antecubital The anterior aspect of the elbow.
anterior The front surface of the body; the side facing forward in the anatomic position.
anterior cavity Aqueous chamber; portion of the eyeball filled with aqueous humor, a fluid whose quantity determines the intraocular pressure, which is critical to sight.
anterior chamber The anterior area of the globe between the lens and the cornea that is filled with aqueous humor.
anterior cord syndrome A condition that occurs with flexion injuries or fractures, resulting in the displacement of bony fragments into the anterior portion of the spinal cord; findings include paralysis below the level of the insult and loss of pain, temperature, and touch sensation.
anterior tibial artery The artery that travels through the anterior muscles of the leg and continues to the foot as the dorsalis pedis.
anterograde amnesia An inability to remember events after the onset of amnesia.
anterograde (posttraumatic) amnesia Loss of memory relating to events that occurred after the injury.
anthrax A deadly bacteria (Bacillus anthracis) that lies dormant in a spore (protective shell); the germ is released from the spore when exposed to the optimal temperature and moisture. The route of entry is inhalation, cutaneous, or gastrointestinal (from consuming food that contains spores).
antibiotics The medications used to fight infection by killing the microorganisms or preventing their multiplication to allow the body’s immune system to overcome them.
antibody (immunoglobulin) A protein secreted by certain immune cells that reacts against foreign antigens in the body by binding to the antigens, making them more visible to the immune system.
anticoagulant A substance that prevents blood from clotting.
antidiuretic hormone (ADH) Secreted by the posterior pituitary lobe of the pituitary gland, this hormone constricts blood vessels and raises the blood pressure, and also is responsible for adjustments to the final composition of urine by causing ducts in the kidney to become more permeable to water; also called vasopressin.
antifungals The medications used to treat fungal infections.
antigen A substance or molecule that, when taken into the body, stimulates immune system response and causes formation of specific protective proteins called antibodies.
antimicrobials The medications used to kill or suppress the growth of microorganisms.
antiseptics Chemicals used to cleanse an area before performing an invasive procedure, such as starting an IV line; not toxic to living tissues; examples include isopropyl alcohol and iodine.
anuria A complete cessation of urine production.
anxiety disorder A mental disorder in which the dominant mood is fear and apprehension.
anxiolysis The relief of anxiety.
anxious avoidant attachment A bond between an infant and his or her parent or caregiver in which the infant is repeatedly rejected and develops an isolated lifestyle that does not depend on the support and care of others.
aorta The principal artery leaving the left side of the heart and carrying freshly oxygenated blood to the body; this is the largest artery in the body.
aortic arch One of the three described portions of the aorta; the section of the aorta between the ascending and descending portions that gives rise to the right brachiocephalic (innominate), left common carotid, and left subclavian arteries.
aortic sclerosis A condition in which the aortic valve thickens due to fibrosis and calcification, obstructing blood flow from the left ventricle.
aortic semilunar valve The valve between the left ventricle and the aorta; also called the aortic valve.
aortic stenosis A condition in which the aortic valve does not open fully, decreasing blood flow from the heart.
aortic valve The semilunar valve that regulates blood flow from the left ventricle to the aorta.
apex (plural: apices) The pointed extremity of a conical structure.
Apgar score Scale used to assess the status of a newborn 1 and 5 minutes after birth (range, 0 to 10); assigns a number value to each of five areas of assessment.
aphasia The impairment of language that affects the production or understanding of speech and the ability to read or write.
aphonia The inability to speak.
aplastic crisis A temporary stop in the production of red blood cells; may occur as a result of sickle cell disease.
apnea Respiratory pause greater than or equal to 20 seconds.
apneustic center A portion of the pons that assists in creating longer, slower respirations.
apneustic respirations Prolonged gasping inspirations followed by extremely short, ineffective expirations; associated with brainstem insult.
apocalyptic violence A type of violence sought by some terrorists, such as violent religious groups and doomsday cults, in which they wish to bring about the end of the world.
apoptosis Normal, genetically programmed cell death.
apparent life-threatening event (ALTE) An unexpected sudden episode of color change, tone change, or apnea that requires mouth-to-mouth resuscitation or vigorous stimulation.
appendicitis Inflammation of the appendix.
appendicular skeleton The part of the skeleton comprising the upper and lower extremities.
appendix A small tubular structure that is attached to the lower border of the cecum in the lower right quadrant of the abdomen.
apraxia A neurologic impairment in which the brain is intermittently unable to carry out the command for speech or other tasks.
aqueous humor Watery fluid filling the anterior eye cavity; the quantity determines the intraocular pressure, which is critical to sight.
arachnoid The middle membrane of the three meninges that enclose the brain and spinal cord.
areolar tissue The type of tissue that binds skin to underlying organs and fills in spaces between muscles.
arrhythmia The lack of a cardiac rhythm; asystole.
arterial air embolism Air bubbles in the arterial blood vessels.
arterial gas embolism (AGE) The resultant gaseous emboli from the forcing of gas into the vasculature from barotrauma.
arteries The muscular, thick-walled blood vessels that carry blood away from the heart.
arteriole A small blood vessel that carries oxygenated blood, branching into yet smaller vessels called capillaries.
arteriosclerosis A pathologic condition in which the arterial walls become thickened and inelastic.
arthritis Inflammation of the joints.
Arthus reaction A localized reaction involving vascular inflammation in response to an IgG-mediated allergic response.
articulations The locations where two or more bones meet; joints.
artifact An artificial product; in cardiology, is used to refer to noise or interference in an ECG tracing.
arytenoid cartilages Pyramid-like cartilaginous structures that form the posterior attachment of the vocal cords.
ascending aorta The first of three portions of the aorta; originates from the left ventricle and gives rise to two arteries, the right and left main coronary arteries.
ascites Abnormal accumulation of fluid in the peritoneal cavity; typically signals liver failure.
aseptic technique A method of cleansing used to prevent contamination of a site when you are performing an invasive procedure, such as starting an IV line.
ashfall The residue left behind from a volcanic eruption.
asphyxia Condition of severely deficient supply of oxygen to the body leading to end organ damage.
asphyxiant Any gas that displaces oxygen from the atmosphere; can be deadly if exposure occurs in a confined space.
aspiration The entry of fluids or solids into the trachea, bronchi, and lungs; the act of drawing material in or out by suction.
assault To create in another person a fear of immediate bodily harm or invasion of bodily security.
asthma A chronic inflammatory lower airway condition resulting in intermittent wheezing and excess mucus production.
astigmatism Condition where parts of the image are out of focus and others are in focus; caused by irregularities in the shape of the eye lens.
astrocytes Neuroglia found usually between neurons and blood vessels.
asymmetric chest wall movement Unequal movement of the two sides of the chest; indicates decreased airflow into one lung.
asymmetric warfare A type of warfare in which groups wage war with unconventional weapons and covert tactics that are unequal—for example, when there are differences in military resources or capabilities.
asynchronous In CPR, when two rescuers perform ventilations and compressions individually and not timed or waiting for the other rescuer to pause.
asynchrony Disturbance or lack of synchronization.
asystole The absence of ventricular contractions; a “straight-line ECG.”
ataxia Alteration in the ability to perform coordinated motions like walking; staggered walk or gait.
atelectasis Alveolar collapse that prevents use of that portion of the lungs for ventilation and oxygenation.
atheroma A mass of fatty tissue.
atherosclerosis A disorder in which cholesterol and calcium build up inside the walls of the blood vessels, forming plaque, which eventually leads to partial or complete blockage of blood flow.
atlanto-occipital joint The joint formed at the articulation of the atlas of the vertebral column and the occipital bone of the skull.
atlas The first cervical vertebra (C1), which provides support for the head.
atmosphere absolute (ATA) A measurement of ambient pressure; the weight of air at sea level, equivalent in pressure to 33 feet of seawater (fsw).
atomic number A whole number representing the number of positively charged protons in the nucleus of an atom.
atomic weight The total number of protons and neutrons in the nucleus of an atom.
atoms The smallest complete units of an element that have the element’s properties; they vary in size, weight, and interaction with other atoms.
atopic The medical term for having an allergic tendency.
atrial kick The volume (percentage) of blood pumped into the ventricles by the atria.
atrial septal defect (ASD) A hole in the atrial septal wall that allows oxygenated and deoxygenated blood to mix; patients with this hole have a higher incidence of stroke.
atrioventricular (AV) node A specialized structure located in the AV junction that slows conduction through the AV junction.
atrioventricular (AV) valves The mitral and tricuspid valves through which blood flows from the atria to the ventricles.
atrium One of the two upper chambers of the heart.
atrophy A decrease in cell size due to a loss of subcellular components; w asting away of a tissue.
atropine A parasympathetic blocker; opposes the action of acetylcholine on the heart and elsewhere, causing an increase in heart rate.
atropine-like effects Results of some antipsychotic medications that include side effects similar to atropine, resulting in dry mouth, blurred vision, urinary retention, and cardiac dysrhythmias.
auditory neuropathy A condition characterized by normal function of the structures of the ear without a corresponding stimulation of auditory centers of the brain; also called auditory dyssynchrony.
auditory ossicles The bones that function in hearing and are located deep within cavities of the temporal bone.
augmented unipolar leads On an ECG, leads that only contain one true pole; the other is a combination of information from other leads; includes leads aVR, aVL, and aVF.
aura Sensations experienced before an attack occurs. Common in seizures and migraine headaches.
aural Pertaining to the ear.
auricle The large outside portion of the ear through which sound waves enter the ear; also called the pinna.
auscultation The method of listening to sounds within the body with a stethoscope.
authoritarian A parenting style that demands absolute obedience.
authoritative A parenting style that balances parental authority with the child’s freedom by setting and enforcing rules, but also allowing the child to have some freedom.
authority having jurisdiction (AHJ) An organization, office, or person responsible for enforcing the requirements of a code or standard, or for approving equipment, materials, an installation, or a procedure.
autism A developmental disorder characterized by impairments of social interaction; may include severe behavioral problems, repetitive motor activities, and impairment in verbal and nonverbal skills.
autoantibodies Antibodies directed against the person’s own proteins.
autocrine hormone A hormone that acts on the cell from which it has been secreted.
autoimmune disease A type of disease in which the body identifies its own antigen as a foreign body and activates the inflammatory system, sending out antibodies to destroy the antigen.
autoimmunity The production of antibodies or T cells that work against the tissues of a person’s own body, producing autoimmune disease or a hypersensitivity reaction.
automated external defibrillator (AED) A “smart” defibrillator that can analyze the patient’s ECG rhythm and determine whether a defibrillating shock is needed.
automatic transport ventilator (ATV) A portable mechanical ventilator attached to a control box that allows the variables of ventilation (such as rate and tidal volume) to be set.
automaticity A state in which cardiac cells are at rest, waiting for the generation of a spontaneous impulse from within.
autonomic dysreflexia A potentially life-threatening late complication of spinal cord injury in which a massive, uninhibited, uncompensated cardiovascular response occurs due to stimulation of the sympathetic nervous system below the level of injury; also known as autonomic hyperreflexia.
autonomic nervous system (ANS) A subdivision of the nervous system that controls primarily involuntary body functions; comprised of the sympathetic and parasympathetic nervous systems.
autoregulation An increase in mean arterial pressure to compensate for decreased cerebral perfusion pressure; compensatory response of the body to shunt blood to the brain; manifests clinically as hypertension.
autosomal dominant A pattern of inheritance that involves genes that are located on autosomes or the nonsex chromosomes. Inheritance of only one copy of a particular form of a gene is needed to show the trait.
autosomal recessive A pattern of inheritance that involves genes located on autosomes or the nonsex chromosomes. Inheritance of two copies of a particular form of a gene is needed to show the trait.
autosomes The chromosomes that do not carry genes that determine sex.
AV junction The atrioventricular junction; the portion of the electric conduction system of the heart located in the upper part of the interventricular septum that conducts the excitation impulse from the atria to the bundle of His.
avascular Lacking blood vessels.
avascular necrosis Tissue death resulting from the loss of blood supply.
avian (bird) flu A disease caused by a virus that occurs naturally in the bird population; signs and symptoms include fever, sore throat, cough, and muscle aches.
AVPU A method of assessing mental status by determining whether a patient is Awake and alert, responsive to Verbal stimuli or Pain, or Unresponsive; used principally in the primary assessment.
avulsing A tearing away or forcible separation.
avulsion An injury that leaves a piece of skin or other tissue partially or completely torn away from the body.
avulsion fracture A fracture that occurs when a piece of bone is torn free at the site of attachment of a tendon or ligament.
awareness The first level of rescue training provided to all responders, with an emphasis on recognizing the hazards, securing the scene, and calling for appropriate assistance. There is no actual use of rescue skills.
axial skeleton The part of the skeleton comprising the skull, spinal column, and rib cage.
axilla The armpit.
axillary artery The artery that runs through the axilla, connecting the subclavian artery to the brachial artery.
axillary vein The vein that is formed from the combination of the basilic and cephalic veins; it drains into the subclavian vein.
axis The second cervical vertebra; the point that allows the head to turn.
axis deviation A component of an ECG that looks at the direction of travel for the electricity going through the heart as it depolarizes.
axon The long, slender filament projecting from a (neuron) nerve cell that conducts electrical impulses to adjacent cells.
azotemia Increased nitrogenous wastes in the blood.
B lymphocytes (B cells) Lymphocytes that exist in the blood, and are abundant in the lymph nodes, bone marrow, intestinal lining, and spleen.
Babinski reflex When the toe(s) moves upward in response to stimulation to the sole of the foot. Under normal circumstances, the toe(s) moves downward.
bacteria Small organisms that can grow and reproduce outside the human cell in the presence of the needed temperature and nutrients and cause disease by invading and multiplying in the tissues of the host.
bacterial tracheitis An invasive exudative bacterial infection of the soft tissues of the trachea.
bacterial vaginosis An overgrowth of bacteria in the vagina, characterized by itching, burning, or pain, and possibly a “fishy” smelling discharge.
bag-mask device A manual ventilation device that consists of a bag, mask, reservoir, and oxygen inlet; capable of delivering up to 100% oxygen.
bandage Material used to secure a dressing in place.
barbiturates Potent sedative-hypnotics historically used as sleep aids, antianxiety drugs, and as part of the regimen for seizure control; include drugs such as thiopental (Pentothal, Trapanal) and methohexital (Brevital).
bariatrics The medical specialty dedicated to prevention and treatment of obesity.
barometric energy The energy that results from sudden changes in pressure as may occur in a diving accident or sudden decompression in an airplane.
baroreceptors Receptors in the blood vessels, kidneys, brain, and heart that respond to changes in pressure in the heart or main arteries to help maintain homeostasis.
barotrauma Injury resulting from pressure disequilibrium across body surfaces, for example from too much pressure in the lungs.
Bartholin glands The glands that secrete mucus for sexual lubrication.
basal ganglia Structures located deep within the cerebrum, diencephalon, and midbrain that have an important role in coordination of motor movements and posture.
basal metabolic rate (BMR) The heat energy produced at rest from normal body metabolic reactions, determined mostly by the liver and skeletal muscles; the rate at which nutrients are consumed in the body
base Any molecule that can accept a hydrogen ion (OH−), and therefore decreases the concentration of hydrogen ions in a water solution.
base station Assembly of radio equipment consisting of at least a transmitter, receiver, and antenna connection at a fixed location.
basement membrane Anchors epithelial tissue to connective tissue.
basilar skull fractures Usually occur following diffuse impact to the head (such as falls, motor vehicle crashes); generally result from extension of a linear fracture to the base of the skull and can be difficult to diagnose with a radiograph (x-ray).
basilic vein One of the two major veins of the arm; it combines with the cephalic vein to form the axillary vein.
basophils White blood cells that work to produce chemical mediators during an immune response; make up approximately 1% of leukocytes.
battery Any act of touching another person without that person’s consent.
Battle sign Bruising over the mastoid bone behind the ear commonly seen following a basilar skull fracture; also called retroauricular ecchymosis and raccoon eyes.
Beck triad The combination of a narrowed pulse pressure, muffled heart tones, and jugular venous distention associated with cardiac tamponade; usually resulting from penetrating chest trauma.
behavior How a person functions or acts in response to his or her environment.
behavioral emergency The point at which a person’s reactions to events interfere with activities of daily living; becomes a psychiatric emergency when it causes a major life interruption, such as attempted suicide.
belay Technique of controlling the rope as it is fed out to climbers.
Bell palsy A temporary paralysis of the facial nerve (cranial nerve VII), which controls the muscles on each side of the face.
belt noise A chirping or squealing sound, synchronous with engine speed.
benign early repolarization Early repolarization that is thought to be a normal variant; characterized by ST-segment elevation (or J-point elevation), a J or fishhook appearance at the J point, and concave ST-segment morphology.
benign prostate hypertrophy (BPH) Age-related nonmalignant (noncancerous) enlargement of the prostate gland.
benzodiazepines The family of sedative-hypnotics that provide muscle relaxation and mild sedation; most commonly used to treat anxiety, seizures, and alcohol withdrawal; include drugs such as diazepam (Valium) and midazolam (Versed).
bereavement Sadness from loss; grieving.
beta Type of energy that is emitted from a strong radiologic source; is slightly more penetrating than alpha, and requires a layer of clothing to stop it.
beta cells Cells located in the islets of Langerhans that secrete insulin.
beta effects Stimulation of beta receptors that results in inotropic, dromotropic, and chronotropic states.
beta-2 agonist A pharmacologic agent that stimulates the beta-2 receptor sites found in smooth muscle; includes common bronchodilators such as albuterol and levalbuterol.
bifascicular block Blockage of any combination of two of the fascicles or conduction pathways: a right bundle branch block (RBBB) and anterior hemiblock, a RBBB and posterior hemiblock, or an anterior hemiblock and posterior hemiblock.
bigeminy A dysrhythmia in which every other heartbeat is a premature contraction; can be atrial or ventricular.
bilateral In anatomy, a body part that appears on both sides of the midline.
bile ducts The ducts that convey bile between the liver and the intestine.
biliary tract disorders A group of disorders that involve inflammation of the gallbladder; these include choleangitis, cholelithiasis, cholecystitis, and acalculus cholecystitis.
bilirubin A waste product of red blood cell destruction that undergoes further metabolism in the liver.
bill of lading A document carried by drivers of commercial vehicles that should provide specific information about what is carried on the vehicle.
binocular vision The merging of two images into one.
bioavailability The percentage of the unchanged medication that reaches systemic circulation.
biomechanics The study of the physiology and mechanics of a living organism using the tools of mechanical engineering.
Biot (ataxic) respirations Irregular pattern, rate, and depth of respirations with intermittent periods of apnea; result from increased intracranial pressure.
biotelemetry Transmission of physiologic data, such as an ECG, from the patient to a distant point of reception (commonly referred to in EMS as “telemetry”).
biotransformation A process with four possible effects on a medication absorbed into the body: (1) An inactive substance can become active, capable of producing desired or unwanted clinical effects. (2) An active medication can be changed into another active medication. (3) An active medication may be completely or partially inactivated. (4) A medication is transformed into a substance (active or inactive) that is easier for the body to eliminate.
bipolar leads On an ECG, leads that contain a positive and a negative pole; includes leads I, II, and III.
bipolar mood disorder A disorder in which a person alternates between mania and depression.
bivalent An ion that contains two charges.
blast front The leading edge of the shock wave.
blastocyst The term for an oocyte once it has been fertilized and multiplies into cells.
blind panic A fear reaction in which a person’s judgment seems to disappear entirely; it is particularly dangerous because it may precipitate mass panic among others.
blind spots Areas of the road that are blocked from your sight by your own vehicle or mirrors.
blinding The method of not giving the specifics of a project to the people participating in a research or study.
blood The fluid tissue that is pumped by the heart through the arteries, veins, and capillaries and consists of plasma and formed elements or cells, such as red blood cells, white blood cells, and platelets.
blood pressure (BP) The measurement of the force exerted against the walls of the blood vessels as the heart contracts and relaxes; it is calculated as the product of cardiac output and peripheral vascular resistance.
blood tubing A special type of macrodrip administration set designed to facilitate rapid fluid replacement by manual infusion of multiple IV bags or IV-blood replacement combinations.
bloodborne pathogens Pathogenic microorganisms that are present in human blood and can cause disease in humans; include, but are not limited to, hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus.
bloody show A plug of mucus, sometimes mixed with blood, that is expelled from the dilating cervix and discharged from the vagina.
blow-by technique A method of delivering oxygen by holding a face mask or similar device near an infant’s or a child’s face; used when a nonrebreathing mask is not tolerated.
blowout fracture A fracture to the floor of the orbit usually caused by a blow to the eye.
blunt trauma An impact on the body by objects that cause injury without penetrating soft tissues or internal organs and cavities.
body-over-frame construction Vehicle design where the body of the vehicle is placed onto a frame skeleton and the frame acts as the foundation for the vehicle. The design consists of two large beams tied together by cross member beams.
bolus A term used to describe “in one mass”; in medication administration, a single dose given by the IV or IO route; may be a small or large quantity of the drug.
bonding The formation of a close, personal relationship.
bone The most rigid type of connective tissue, with high mineral content that makes it harder than the other types.
Bone Injection Gun (BIG) A spring-loaded device that is used for inserting an IO needle into the proximal tibia in adult and pediatric patients.
bone marrow Specialized tissue found within bone that manufactures most erythrocytes.
bony labyrinth The collection of hollows in the bone of the inner ear that provide protection to the structures of the inner ear from damage and from extraneous stimulation.
borborygmi A bowel sound characterized by increased activity within the bowel; also called hyperperistalsis.
borderline personality disorder A disorder characterized by disordered images of self, impulsive and unpredictable behavior, marked shifts in mood, and instability in relationships with others.
botulinum A very potent neurotoxin produced by bacteria; when introduced into the body, this neurotoxin affects the nervous system’s ability to function and causes muscle paralysis.
botulism Poisoning from eating food containing botulinum toxin.
Bourdon-gauge flowmeter An oxygen flowmeter that is commonly used because it is not affected by gravity and can be placed in any position.
bowing fracture An incomplete fracture typically occurring in children in which the bone becomes bent as the result of a compressive force.
boxer’s fracture A fracture of the head of the fifth metacarpal that usually results from striking an object with a clenched fist.
Boyle’s law At a constant temperature, the volume of a gas is inversely proportional to its pressure (if you double the pressure on a gas, you halve its volume); written as PV = K, where P = pressure, V = volume, and K = a constant.
brachial artery The artery that runs through the arm and branches into the radial and ulnar arteries.
bradycardia A pulse rate of less than 100 beats/min in the newborn.
bradykinesia The slowing down of voluntary body movements. Found in Parkinson disease.
bradypnea A slow respiratory rate.
brain Part of the central nervous system located within the cranium; contains billions of neurons that serve a variety of vital functions; serves as the center of consciousness; functions include perception, control of reactions to the environment, emotional responses, and judgment.
brainstem The midbrain, pons, and medulla, collectively; the area of the brain between the spinal cord and cerebrum, surrounded by the cerebellum; controls functions that are necessary for life, such as respiration.
brake fade A sensation that an ambulance has lost its power brakes.
brake pull A sensation that, when an operator depresses the brake pedal, the steering wheel is being pulled to the left or the right.
breath-hold diving Also called free diving, this type of diving does not require any equipment, except sometimes a snorkel.
breech presentation A delivery in which the buttocks come out first.
brisance The shattering effect of a shock wave and its ability to cause disruption of tissues and structures.
bronchi The main branches of the trachea; subdivide into smaller bronchi and bronchioles that conduct air into and out of the lungs.
bronchioles Fine subdivisions of the bronchi that give rise to the alveolar ducts; made of smooth muscle and dilate or constrict in response to various stimuli.
bronchiolitis A condition seen in children younger than 2 years, characterized by dyspnea and wheezing.
bronchoconstriction Narrowing of the bronchial tubes.
bronchodilation Widening of the bronchial tubes.
bronchophony A test of decreased breath sounds performed by placing the diaphragm of the stethoscope over the area in question while the patient says “ninety-nine”; a loud, clear sound indicates lung consolidation.
bronchopulmonary dysplasia A spectrum of lung conditions found in premature neonates who require long periods of high-concentration oxygen and ventilator support, ranging from mild reactive airways to debilitating chronic lung disease.
bronchospasm Severe constriction of the bronchial tree.
bronchovesicular sounds A combination of the tracheal and vesicular breath sounds; heard where airways and alveoli are found, the upper part of the sternum and between the scapulas.
Brown-Séquard syndrome A condition associated with penetrating trauma with hemisection of the spinal cord and complete damage to all spinal tracts on the involved side.
Brugada syndrome A genetic disorder involving sodium channels in the heart; characterized by incomplete RBBB and ST-segment elevation that aggressively returns to baseline.
bruits Abnormal whooshing sounds indicating turbulent blood flow within a narrowed blood vessel, usually heard in the carotid arteries.
buboes Enlarged lymph nodes (up to the size of tennis balls) that are characteristic of people infected with the bubonic plague.
bubonic plague An epidemic that spread throughout Europe in the Middle Ages, causing over 25 million deaths, also called the Black Death; transmitted by infected fleas and characterized by acute malaise, fever, and the formation of tender, enlarged, inflamed lymph nodes that appear as lesions, called buboes.
buccal Between the cheek and gums.
buckle fracture A common incomplete fracture in children in which the cortex of the bone fractures from an excessive compression force; also called a torus fracture.
buddy splinting Securing an injured digit to an adjacent uninjured one to allow the intact digit to act as a splint.
buffer system Fast-acting defenses for acid-base changes, providing almost immediate protection against changes in the hydrogen ion concentration of extracellular fluid.
buffers Molecules that modulate changes in pH to keep it in the physiologic range; they do this by reversibly binding with H+.
bulbourethral glands Cowper’s glands; glands that lie inferior to the prostate gland and secrete a lubricating fluid that prepares the penis for sexual intercourse.
bulimia nervosa An eating disorder characterized by consumption of large amounts of food, and for which the patient then sometimes compensates by using purging techniques.
bundle branch block A disturbance in electric conduction through the right or left bundle branch from the bundle of His.
bundle of His The portion of the electric conduction system in the interventricular septum that conducts the depolarizing impulse from the atrioventricular junction to the right and left bundle branches.
burn shock The shock or hypoperfusion caused by a burn injury and the tremendous loss of fluids; capillaries leak, resulting in intravascular fluid volume oozing out of the circulation and into the interstitial spaces, and cells take in increased amounts of salt and water.
burnout The exhaustion of physical or emotional strength.
BURP maneuver The backward, upward, rightward pressure used during intubation to improve the laryngoscopic view of the glottic opening and vocal cords; also called external laryngeal manipulation.
bursa A small fluid-filled sac located between a tendon and a bone that cushions and protects the joint.
bursitis Inflammation of a bursa.
butterfly catheter A rigid, hollow, venous cannulation device identified by its plastic “wings” that act as anchoring points for securing the catheter.
butyrophenones Potent, effective sedatives; include drugs such as haloperidol (Haldol) and droperidol (Inapsine).
caladium A common houseplant that contains caladium oxalate crystals; ingestion leads to nausea, vomiting, and diarrhea.
calcaneus The heel bone; the largest of the tarsal bones.
calcitonin The hormone secreted by the thyroid gland that helps maintain normal calcium levels in the blood.
calorie The amount of heat needed to raise the temperature of a gram of water by 1°C.
calyces (singular: calyx) Large urinary tubes that branch off the renal pelvis and connect with the renal pyramids to collect the urine draining from the collecting tubules.
CAMEO Computer-Aided Management of Emergency Operations; a tool to help predict downwind concentrations of hazardous materials based on the input of environmental factors into a computer model.
cancellous bone A type of bone that consists of a lacy network of bony rods called trabeculae.
cancer Excessive growth and division of abnormal cells within the body that can occur in many body systems, tissues, and organs, and that can progress rapidly and cause death in a relatively short period of time.
candidiasis A vaginal infection that is not technically a sexually transmitted infection, and which can occur in a pregnant or nonpregnant female, but which is more common in pregnancy; also called thrush or a yeast infection.
cannulation The insertion of a catheter, such as into a vein to allow for fluid flow.
capacitance vessels The smallest venules.
cape cyanosis Deep cyanosis of the face and neck and across the chest and back; associated with little or no blood flow; a particularly ominous sign.
capillaries The tiny blood vessels between the arterioles and venules, composed of a single layer of cells, that permit transfer of oxygen, carbon dioxide, nutrients, and waste between body tissues and the blood.
capillary refill time A test done on the fingernails or toenails by briefly squeezing the toenail or fingernail and evaluating the time it takes for the color to return.
capnographer A device that attaches between the endotracheal tube and bag-mask device; provides graphic information about the presence of exhaled CO2.
capnography A noninvasive diagnostic tool that can quickly and efficiently provide information on a patient’s ventilatory and circulatory status.
capnometer A device that performs the same function and attaches in the same way as a capnographer but provides a digital reading of the exhaled CO2.
capnometry The use of a capnometer, a device that measures the amount of expired carbon dioxide.
carbohydrates Substances (including sugars and starches) that provide much of the energy required by the body’s cells, as well as helping to build cell structures.
carbon monoxide A chemical asphyxiant that results in a cellular respiratory failure; this gas ties up hemoglobin to the extent that oxygen in the blood becomes inaccessible to the cells.
carboxyhemoglobin (COHb) Hemoglobin loaded with carbon monoxide (CO).
carboy A glass, plastic, or steel nonbulk storage container, ranging in volume from 5 to 15 gallons.
cardiac cycle The period from one cardiac contraction to the next. Each cardiac cycle consists of ventricular contraction (systole) and relaxation (diastole).
cardiac muscle tissue A special striated muscle of the myocardium, containing dark intercalated disks at the junctions of abutting fibers.
cardiac output (CO) The volume of blood pumped by the heart per minute. Calculated by multiplying the stroke volume by the heart rate per minute.
cardiac sphincter Sphincter that serves as a doorway connecting the esophagus and the stomach; controls the amount of food that moves up the esophagus.
cardiac tamponade A condition in which the atria and right ventricle are collapsed by a collection of blood or other fluid within the pericardial sac, resulting in a diminished cardiac output.
cardiogenic shock A condition caused by loss of 40% or more of the functioning myocardium; the heart is no longer able to circulate sufficient blood to maintain adequate oxygen delivery.
cardiopulmonary arrest The sudden and often unexpected cessation of adequate cardiac output.
cardiovascular collapse Failure of the heart and blood vessels; shock.
cargo tank Bulk packaging that is permanently attached to or forms a part of a motor vehicle, or is not permanently attached to any motor vehicle, and that, because of its size, construction, or attachment to a motor vehicle, is loaded or unloaded without being removed from the motor vehicle.
carina A ridgelike projection of tracheal cartilage located where the trachea bifurcates into the right and left mainstem bronchi.
carotid artery The major artery that supplies blood to the head and brain.
carotid bifurcation The point of division at which the common carotid artery branches at the angle of the mandible into the internal and external carotid arteries.
carpal tunnel syndrome Compression of the median nerve at the wrist where it passes through the carpal canal, causing numbness and tingling in the hand, and possibly pain.
carpals The eight small bones of the wrist.
carpometacarpal joint The joint between the wrist and the metacarpal bones; the thumb joint.
carpopedal spasm Contorted position of the hand or foot in which the fingers or toes flex in a clawlike manner; may result from hyperventilation or hypocalcemia.
carriers People who harbor an infectious agent and, although not personally ill, can transmit the infection to other people.
cartilage The support structure of the skeletal system that provides cushioning between bones; also forms the nasal septum and portions of the outer ear.
cartilaginous joints Joints that are spanned completely by cartilage and allow for minimal motion.
case study A type of research in which a single case is investigated and documented over a period of time.
castor bean A seed that contains the poison ricin; causes a variety of toxic effects: burning of the mouth and throat; nausea, vomiting, diarrhea, and severe stomach pains; prostration; failing vision; and kidney failure, which is the usual cause of death.
casualty collection points Areas where slightly injured or noninjured displaced persons can be gathered together and transported by bus or truck for further treatment.
catabolism The breakdown of larger molecules into smaller ones.
cataract A clouding of the lens of the eye or its surrounding transparent membrane; normally a result of aging; leads to decreased vision.
catatonic Lacking expression or movement, or appearing rigid.
catecholamines Hormones produced by the adrenal medulla (epinephrine and norepinephrine) that assist the body in coping with physical and emotional stress by increasing the heart and respiratory rates and the blood pressure.
catheter shear Occurs when a needle is reinserted into the catheter, and it slices through the catheter, creating a free-floating segment.
cation An ion that contains an overall positive charge.
cauda equina The location where the spinal cord separates, composed of nerve roots.
cauda equina syndrome A neurologic condition caused by compression of the bundle of nerve roots located at the end of the spinal cord.
caustics Chemicals that are acids or alkalis; cause direct chemical injury to the tissues they contact.
cavitation Cavity formation; shock waves that push tissues in front of and lateral to the projectile and may not necessarily increase the wound size or cause permanent injury but can result in cavitation.
cecum The first part of the large intestine, into which the ileum opens.
cell membrane The cell wall; a selectively permeable layer of cells that surround intracellular contents and control movement of substances into and out of the cell.
cell signaling The process by which cells communicate with one another.
cell-mediated immunity The immune process by which T-cell lymphocytes and macrophages attack and destroy pathogens or foreign substances; the process involves recognizing antigens, then secreting cytokines (specifically lymphokines) that attract other cells or stimulate the production of cytotoxic cells that kill the infected cells.
cellular immune response Cell-mediated immunity; it occurs when T cells attach to foreign, antigen-bearing cells such as bacterial cells, and interact with direct cell-to-cell contact.
cellular immunity The immunity provided by special white blood cells called T cells that attack and destroy invaders.
cellular metabolism Process within a cell where nutrients can be broken down from complex to simpler forms or complex forms can be built from those building blocks.
cellular respiration A biochemical process resulting in the production of energy in the form of adenosine triphosphate; also called metabolism.
cellular telephones Low-power portable radios that communicate through an interconnected series of repeater stations called “cells.”
cellulitis An acute inflammation in the skin caused by a bacterial infection.
Celsius scale A scale for measuring temperature where water freezes at 0° and boils at 100°.
central auditory processing disorder (CAPD) A disorder in which patients have difficulty interpreting speech and differentiating it from other sounds that are present.
central cord syndrome A condition resulting from hyperextension injuries to the cervical area that cause damage with hemorrhage or edema to the central cervical segments; findings include greater loss of function in the upper extremities with variable sensory loss of pain and temperature.
central cyanosis Bluish coloration of the skin due to the presence of deoxygenated hemoglobin in blood vessels near the skin surface.
central nervous system (CNS) The system containing the brain and spinal cord.
central neurogenic hyperventilation Deep, rapid respirations; similar to Kussmaul, but without an acetone breath odor; commonly seen following brainstem injury.
central shock A type of shock caused by central pump failure, including cardiogenic shock and obstructive shock.
central venous catheter A catheter inserted into the vena cava to permit intermittent or continuous monitoring of central venous pressure and to facilitate obtaining blood samples for chemical analysis.
central vision The visualization of objects directly in front of you.
cephalic vein One of the two major veins of the arm that combine to form the axillary vein.
cephalopelvic disproportion A situation in which the head of the fetus is larger than the woman’s pelvis; in most cases, cesarean section is required for such a delivery.
cerebellum One of the three major subdivisions of the brain, sometimes called the “little brain”; coordinates the various activities of the brain, particularly fine body movements.
cerebral concussion Occurs when the brain is jarred around in the skull; a mild diffuse brain injury that does not result in structural damage or permanent neurologic impairment.
cerebral contusion A focal brain injury in which brain tissue is bruised and damaged in a defined area.
cerebral cortex The largest portion of the cerebrum; regulates voluntary skeletal movement and one’s level of awareness—a part of consciousness.
cerebral edema Cerebral water; causes or contributes to swelling of the brain.
cerebral palsy (CP) A developmental condition in which damage is done to the brain. It presents during infancy as a delay in walking or crawling, and can take on a spastic form in which muscles are in a nearly constant state of contraction.
cerebral perfusion pressure (CPP) The pressure of blood flow through the brain; the difference between the mean arterial pressure (MAP) and intracranial pressure (ICP).
cerebrospinal fluid (CSF) Fluid produced in the ventricles of the brain that flows in the subarachnoid space and bathes the meninges.
cerebrospinal fluid shunt (CSF shunt) A tube placed in the body to relieve pressure by drawing excess cerebrospinal fluid away from the brain or spinal cord.
cerebrospinal otorrhea Cerebrospinal fluid drainage from the ears.
cerebrospinal rhinorrhea Cerebrospinal fluid drainage from the nose.
cerebrum The largest part of the three subdivisions of the brain, sometimes called the “gray matter”; divided into right and left hemispheres, or halves; made up of several lobes that control movement, hearing, balance, speech, visual perception, emotions, and personality.
certification A process in which a person, an institution, or a program is evaluated and recognized as meeting certain predetermined standards to provide safe and ethical care.
cerumen Ear wax.
cervical canal The interior of the cervix.
cervical spine The portion of the spinal column consisting of the first seven vertebrae that lie in the neck.
cervix The narrowest portion of the uterus that opens into the vagina.
chalazion A small, swollen bump or pustule on the external eyelid, resulting when the eyelid’s oil glands or ducts become blocked.
chancre The primary hard lesion or ulcer of syphilis that occurs at the entry site of the infection.
chancroid A highly contagious sexually transmitted disease caused by the bacteria Haemophilus ducreyi, which causes painful sores (ulcers), usually of the genitals.
CHARTE method A narrative writing method that allows the narrative to be broken down into logical sections similar to the steps of the EMS assessment; components include chief complaint, history, assessment, treatment, transport, and exceptions.
chelating agents Medications that bind with heavy metals in the body and create a compound that can be eliminated; used in cases of ingestion or poisoning.
chemical asphyxiants Substances that interfere with the use of oxygen at the cellular level.
chemical energy The energy released as a result of a chemical reaction.
chemical mediators Chemicals that work to cause the immune or allergic response; for example, histamine.
chemoreceptors Sense organs that monitor the levels of oxygen and carbon dioxide and the pH of cerebrospinal fluid and blood and provide feedback to the respiratory centers to modify the rate and depth of breathing based on the body’s needs at any given time.
chemotactic factors The factors that cause cells to migrate into an area.
chemotaxins Components of the activated complement system that attract leukocytes from the circulation to help fight infections.
chemotaxis The movement of additional white blood cells to an area of inflammation in response to the release of chemical mediators, such as neutrophils, injured tissue, and monocytes.
CHEMTREC (Chemical Transportation Emergency Center) A resource available to emergency responders via telephone on a 24-hour basis.
Cheyne-Stokes respirations A gradually increasing rate and depth of respirations followed by a gradual decrease with intermittent periods of apnea; associated with brainstem insult.
chickenpox A very contagious disease caused by the varicella zoster virus, which is part of the herpes virus family, occurring most often in the winter and early spring.
chief complaint The problem for which the patient is seeking help.
chilblains Itchy reddish and purple swollen lesions that occur primarily on the extremities, due to longer exposure to temperatures just above freezing or sudden rewarming after exposure to cold.
child abuse Any improper or excessive action that injures or otherwise harms a child or infant; it includes physical abuse, sexual abuse, neglect, and emotional abuse.
child protective services (CPS) An agency that is the community legal organization responsible for protection, rehabilitation, and prevention of child maltreatment and neglect; it has the legal authority to temporarily remove children from homes if there is reason to believe they are at risk for injury or neglect and to secure foster placement.
chlamydia A sexually transmitted disease (STD) caused by the bacterium Chlamydia trachomatis; has the highest incidence in sexually transmitted diseases; signs and symptoms include inflammation of the urethra, epididymis, cervix, and fallopian tubes, and discharge from the urethra.
chlorine (CL) The first chemical agent ever used in warfare. It has a distinct odor of bleach, and creates a green haze when released as a gas. Initially it produces upper airway irritation and a choking sensation.
choanal atresia A narrowing or blockage of the nasal airway by membranous or bony tissue; a congenital condition, meaning it is present at birth.
choleangitis Inflammation of the bile duct.
cholecystitis Inflammation of the gallbladder.
cholelithiasis The presence of stones within the gallbladder.
cholestasis A disease of the liver that occurs only during pregnancy, in which hormones affect the gallbladder by slowing down or blocking the normal bile flow from the liver; the most common symptom is profuse, painful itching, particularly of the hands and feet.
cholinergic A term used to describe the fibers in the parasympathetic nervous system that release a chemical called acetylcholine.
chordae tendineae Thin bands of fibrous tissue that attach to the valves in the heart and prevent them from inverting.
choroid The vascular, pigmented middle layer of the eye wall.
choroid plexus Specialized capillaries within hollow areas in the ventricles of the brain that produce cerebrospinal fluid.
chromosomes Structures formed from condensed DNA fibers and protein; they are thread-like, and are contained within the nucleus of the cells.
chronic bronchitis A chronic inflammatory condition affecting the bronchi that is characterized by excessive mucus production as a result of overgrowth of the mucous glands in the airways.
chronic hypertension A blood pressure that is equal to or greater than 140/90 mm Hg, which exists prior to pregnancy, occurs before the 20th week of pregnancy, or continues to persist postpartum.
chronic obstructive pulmonary disease (COPD) A progressive and irreversible disease of the airway marked by decreased inspiratory and expiratory capacity of the lungs.
chronic renal failure (CRF) Progressive and irreversible inadequate kidney function caused by the permanent loss of nephrons.
chronotropic effect The effect on the rate of contraction of the heart.
chyme The name given to the substance that leaves the stomach once food is digested; it is a combination of all of the eaten foods with added stomach acids.
cilia The hairlike microtubule projections on the surface of a cell that can move materials over the cell surface.
ciliary body The structure associated with the choroid layer of the eye that secretes aqueous humor and contains the ciliary muscle.
circulatory system The complex arrangement of connected tubes, including the arteries, arterioles, capillaries, venules, and veins, that moves blood, oxygen, nutrients, carbon dioxide, and cellular waste throughout the body.
circumferential burns Burns on the neck or chest that may compress the airway or on an extremity that might act like a tourniquet.
circumflex coronary artery One of the two branches of the left main coronary artery.
circumstantial thinking Situation in which the patient includes many irrelevant details in his or her account of things.
cirrhosis Early failure of the liver; characterized by portal hypertension, coagulation deficiencies, and diminished detoxification.
civil suit An action instituted by a private person or corporation against another private person or corporation.
clandestine drug laboratories Locations where illegal drugs such as methamphetamine, lysergic acid diethylamide (LSD), ecstasy, and phencyclidine hydrochloride (PCP) are manufactured.
class How a medication is categorized as compared to other medications. This is usually done by grouping those medications with similar characteristics, traits, or primary components.
classic heatstroke Also called passive heatstroke, this is a serious heat illness that usually occurs during heat waves and is most likely to strike very old, very young, or bedridden people.
claudication A severe pain in the calf muscle that is caused by narrowing of the arteries in this muscle and that leads to a painful limp.
clavicle The collarbone; it is lateral to the sternum and anterior to the scapula.
cleaning The process of removing dirt, dust, blood, or other visible contaminants from a surface.
cleft lip An abnormal defect or fissure in the upper lip that failed to close during development. It is often associated with cleft palate.
cleft palate A fissure or hole in the palate (roof of the mouth) that forms a communicating pathway between the mouth and nasal cavities.
clitoris In females, a small, cylindrical mass of erectile tissue and nerves located at the anterior junction of the labia minora, similar to the glans penis of the male.
clonic activity Type of seizure movement involving the contraction and relaxation of muscle groups.
closed abdominal injury An injury in which there is soft-tissue damage inside the body, but the skin remains intact.
closed fracture A fracture in which the skin is not broken.
closed incident A contained incident in which patients are found in one focal location and the situation is not expected to produce more patients than initially present.
closed wound An injury in which damage occurs beneath the skin or mucous membrane but the surface remains intact.
closed-ended question A question that is specific and focused, demanding either a yes or no answer or an answer chosen from specific options.
clotting cascade The term that refers to the process by which clotting factors work together to ultimately form fibrin.
clotting factors Substances in the blood that are necessary for clotting; also called coagulation factors.
coagulation Clotting of the blood.
coagulation system The system that forms blood clots in the body and facilitates repairs to the vascular tree.
coagulopathy Any type of bleeding disorder that interferes with the activation or continuation of the clotting cascade or hemostasis.
coarctation of the aorta (CoA) Pinching or narrowing of the aorta that obstructs blood flow from the heart to the systemic circulation.
Cobra perilaryngeal airway (CobraPLA) A supraglottic airway device with a shape that allows the device to slide easily along the hard palate and to hold the soft tissue away from the laryngeal inlet.
cocaine A stimulant; a naturally occurring alkaloid that is extracted from the Erythroxylon coca plant leaves found in South America.
coccyx The last three or four vertebrae of the spine; the tailbone.
cochlea The shell-shaped structure within the inner ear that contains the organ of Corti.
cochlear duct A canal within the cochlea that receives vibrations from the ossicles.
code team leader The code team member who has the responsibility for managing the rescuers or team members during a cardiac arrest, as well as choreographing the effort of the group.
code team member A member of the resuscitation team trying to revive the patient.
cohort research A type of research that examines patterns of change, a sequence of events, or trends over time within a certain population of study subjects.
coining A cultural ritual intended to treat an illness by rubbing hot coins, often on the torso, which produces rounded and oblong red, patchy, flat skin lesions.
cold diuresis Secretion of large amounts of urine in response to cold exposure and the consequent shunting of blood volume to the body core.
cold protective response Phenomenon associated with cold water immersion in which reflexes in the body and a lowered metabolic rate help preserve basic body functions.
cold stress A psychological condition that can develop in people who are exposed to cold weather for long periods of time, even if sheltered.
cold zone A safe area for those agencies involved in the operations; the incident commander (IC), command post, EMS providers, and other support functions necessary to control the incident should be located in the cold zone.
collagen A protein that gives tensile strength to the connective tissues of the body.
collagen vascular diseases A group of autoimmune disorders that affect the collagen in tendons, bones, and connective tissues.
collateral circulation The mesh of arteries and capillaries that supplies blood to a segment of tissue whose original arterial supply has been obstructed.
colloid solutions Solutions that contain molecules (usually proteins) that are too large to pass out of the capillary membranes and, therefore, remain in the vascular compartment.
colonized A pathogen is present but has produced no illness in the host; often progresses to active infection; a colonized host is often called a carrier because he or she can transmit the pathogen to others.
colorimetric capnographer A device that attaches between the endotracheal tube and bag-mask device; uses special paper that should turn from purple to yellow during exhalation, indicating the presence of exhaled CO2.
colostomy The surgical establishment of an opening between the colon and the surface of the body for the purpose of providing drainage of the bowel.
colostomy bag A plastic pouch or bag attached over a colostomy to collect stool.
coma A state in which a person does not respond to verbal or painful stimuli.
Combitube A multilumen airway device that consists of a single tube with two lumens, two balloons, and two ventilation ports; an alternative device if endotracheal intubation is not possible or has failed.
comedo A noninflammatory acne lesion.
comfort care Medical treatment aimed at symptom relief and providing comfort for the patient.
command In incident command, the position that oversees the incident, establishes the objectives and priorities, and from there develops a response plan.
comminuted fracture A fracture in which the bone is broken into three or more pieces.
common reality Sensory stimulation that can be verified by others.
commotio cordis An event in which an often fatal cardiac dysrhythmia is produced by a sudden blow to the thoracic cavity.
communicability The ease with which a disease spreads from one human to another human.
communicable disease An infectious disease that can be transmitted from one person to another by direct contact or by indirect contact through a vector or fomite; also called contagious disease.
communicable period The period during which an infected person can transmit a communicable disease to someone else.
compact bone A type of bone that is mostly solid.
compartment syndrome A condition that develops when edema and swelling result in increased pressure within soft tissues, causing circulation to be compromised, possibly resulting in tissue necrosis.
compensated shock (classes I and II) The early stage of shock, in which the body can still compensate for blood loss. The systolic blood pressure and brain perfusion are maintained.
competitive antagonists The medications that temporarily bind with cellular receptor sites, displacing agonist chemicals.
competitive depolarizing A term used to describe paralytic agents that act at the neuromuscular junction by binding with nicotinic receptors on muscles, causing fasciculations and preventing additional activation by acetylcholine.
complement A group of proteins in plasma and other body fluids that interact to cause inflammation and phagocytic activities.
complement system A group of plasma proteins whose function is to do one of three things: attract leukocytes to sites of inflammation, activate leukocytes, and directly destroy cells.
complete abortion Expulsion of all products of conception from the uterus.
complete fracture A fracture in which the bone is broken into two or more completely separate pieces.
complete spinal cord injury Total disruption of all tracts of the spinal cord, with all cord-mediated functions below the level of transection lost permanently.
complex access Complicated entry that requires special tools and training and includes breaking windows or using other force.
complex febrile seizures An unusual form of seizure that occurs in association with a rapid increase in body temperature.
complex partial seizures Seizures characterized by alteration of consciousness with or without complex focal motor activity.
compound fracture An open fracture; a fracture beneath an open wound.
compounds Molecules made up of different bonded atoms.
compulsions Repetitive actions carried out to relieve the anxiety of obsessive thoughts.
concealment Protection from being seen.
concentration The amount of a medication that is present in the ampule or vial; usually expressed in milligrams, grams, or grains.
concentration gradient The natural tendency for substances to flow from an area of higher concentration to an area of lower concentration, within or outside the cell.
concept formation Pattern of understanding based on initially obtained information.
concordant precordial pattern A pattern in which the QRS complexes are all in the same direction in the precordial leads.
conduction Transfer of heat to a solid object or a liquid by direct contact.
conductive hearing loss A type of hearing impairment due to problems with the middle ear bones’ ability to conduct sounds from the outer ear to the inner ear.
conductivity The property that enables cardiac cells to pass an electrical impulse from one cell to another.
cones One of two photoreceptors of the retina that can distinguish colors, but requires a greater amount of light to activate and create an image.
confabulation The invention of experiences to cover gaps in memory, seen in patients with certain organic brain syndromes.
confined space A space with limited or restricted access that is not meant for continuous occupancy, such as a manhole, well, or tank.
confirmation bias Occurs with the tendency to gather and rely on information that confirms your existing views and to avoid or downplay information that does not conform to your preexisiting hypothesis or field differential.
confrontation Pointing out something of interest in the patient’s conversation or behavior, thereby directing the patient’s attention to something he or she may have been unaware of.
congenital adrenal hyperplasia (CAH) Inadequate production of cortisol and aldosterone by the adrenal gland.
congenital heart disease (CHD) The most common birth defect; associated with hypoxia in the newborn period requiring intervention during the first months of life; often lead to cyanosis.
congestive heart failure (CHF) A condition that occurs when the heart is unable to pump powerfully enough or fast enough to empty its chambers; as a result, blood backs up into the systemic circuit, the pulmonary circuit, or both.
conjunctiva A thin, transparent membrane that covers the sclera and internal surfaces of the eyelids.
conjunctivitis An inflammation of the conjunctivae that usually is caused by bacteria, viruses, allergies, or foreign bodies; should be considered highly contagious; also called pink eye.
connective tissues Tissues that bind, support, protect, frame, and fill body structures; they also store fat, produce blood cells, repair tissues, and protect against infection.
Consensus formula A formula that recommends giving 4 mL of normal saline for each kilogram of body weight, multiplied by the percentage of body surface area burned; sometimes used to calculate fluid needs during lengthy transport times; formerly called the Parkland formula.
consent Agreement by the patient to accept a medical intervention.
contact and cover Technique that involves one paramedic making contact with the patient to provide care, while the second paramedic obtains patient information, gauges the level of tension, and warns his or her partner at the first sign of trouble.
contact burn A burn produced by touching a hot object.
contact hazard A hazardous agent that gives off little or no vapors; the skin is the primary route for this type of chemical to enter the body; also called a skin hazard.
contact transmission The transmission of an infectious agent by means of direct or indirect contact with the infected persons, such as skin-to-skin contact or contact with the patient’s environment.
contagious An adjective used to describe the ability of a person infected with a highly communicable disease to pass that disease to another person.
contagious disease See communicable disease.
container Any vessel or receptacle that holds material, including storage vessels, pipelines, and packaging.
contaminated The presence or the reasonably anticipated presence of blood or other potentially infectious materials on an item or surface.
contaminated stick The puncturing of an emergency care provider’s skin with a needle or catheter that was used on a patient.
contiguous leads Leads that view geographically similar areas of the myocardium; useful for localizing areas of ischemia.
continuity of operations plan (COOP) The detailed plan describing the functioning of the agency in situations that disrupt normal operations.
continuous positive airway pressure (CPAP) A method of ventilation used primarily in the treatment of critically ill patients with respiratory distress; can prevent the need for endotracheal intubation.
continuous quality improvement (CQI) A system of internal and external reviews and audits of all aspects of an EMS system.
contraceptive device A device used to prevent pregnancy.
contractility The strength of heart muscle contraction.
contraindication Any condition, especially any condition of disease, that renders some particular line of treatment improper or undesirable.
contributory negligence Act(s) committed by plaintiff that contributes to adverse outcomes.
contusion A bruise; an injury that causes bleeding beneath the skin but does not break the skin.
convection Mechanism by which body heat is picked up and carried away by moving air currents.
convenience sampling A type of research in which subjects are manually assigned to a specific person or crew, rather than being randomly assigned; the least-preferred component of research.
conventional reasoning A type of reasoning in which a child looks for approval from peers and society.
conversion disorder A psychological condition in which stress or mental conflict is converted into physical complaints.
conversion hysteria A reaction in which a person subconsciously transforms his or her anxiety into a bodily dysfunction; the person may be unable to see or hear or may become partially paralyzed.
cookbook medicine Blindly following a protocol or algorithm without thinking about what you are doing and whether or not it is working.
CO-oximeter A device that measures absorption at several wavelengths to distinguish oxyhemoglobin from carboxyhemoglobin.
cor pulmonale Heart disease that develops because of chronic lung disease, affecting primarily the right side of the heart.
core body temperature (CBT) The temperature in the part of the body comprising the heart, lungs, brain, and abdominal viscera.
cornea The transparent anterior portion of the eye that overlies the iris and pupil.
corneal reflex A protective movement that results in blinking, moving the head posteriorly, and pupillary constriction.
coronal plane An imaginary plane where the body is cut into front and back parts.
coronal suture The point where the parietal bones join with the frontal bone.
coronary arteries Arteries that arise from the aorta shortly after it leaves the left ventricle and supply the heart with oxygen and nutrients.
coronary artery disease (CAD) A pathologic process caused by atherosclerosis that leads to progressive narrowing and eventual obstruction of the coronary arteries.
coronary sinus Veins that collect blood that is returning from the walls of the heart.
coronary sulcus The groove along the exterior surface of the heart that separates the atria from the ventricles.
corpus callosum A deep bridge of nerve fibers connecting the brain hemispheres.
corpus luteum The remains of a follicle after an oocyte has been released, and which secretes progesterone.
corrosives A class of chemicals with either high or low pH levels. Exposure can cause severe soft-tissue damage.
cortex Part of the internal anatomy of the kidney; the lighter-colored outer region closest to the capsule.
corticosteroids Hormones secreted by the adrenal gland, and which regulate the body’s metabolism, the balance of salt and water in the body, the immune system, and sexual function.
cortisol A hormone of the middle adrenal cortex that influences protein and fat metabolism and stimulates glucose to be synthesized from noncarbohydrates; stimulates most body cells to increase their energy production.
countercurrent multiplier The process by which the body produces either concentrated or diluted urine, depending on the body’s needs.
coup-contrecoup injury Dual impacting of the brain into the skull; coup injury occurs at the point of impact; contrecoup injury occurs on the opposite side of impact, as the brain rebounds.
couplet Two premature ventricular contractions occurring sequentially.
covalent bond A chemical bond where atoms complete their outer electron shells by sharing electrons.
cover Obstacles that are difficult or impossible for bullets to penetrate.
covert Act in which the public safety community generally has no prior knowledge of the time, location, or nature of the attack.
covert behavior Behavior that has a hidden meaning or intention that only the person understands.
crackles The breath sounds produced as fluid-filled alveoli pop open under increasing inspiratory pressure; can be fine or coarse; formerly called rales.
cranial nerves The 12 pairs of nerves that arise from the base of the brain.
cranial vault The bones that encase and protect the brain, including the parietal, temporal, frontal, occipital, sphenoid, and ethmoid bones; also called the cranium or skull.
craniofacial disjunction A Le Fort III fracture involves a fracture of all of the midfacial bones, thus separating the entire midface from the cranium.
cranium The area of the head above the ears and eyes; the skull. The cranium contains the brain.
creatine phosphate An organic compound in muscle tissue that can store and provide energy for muscle contraction.
crenation Shrinkage of a cell that results when too much water leaves the cell through osmosis.
crepitus Crackling, grating, or grinding that is often felt or heard when two ends of bone rub together.
cretinism A disease caused by lack of thyroid hormone during pregnancy; it results in severely stunted physical and mental development.
cribbing Short lengths of wood that are used to stabilize vehicles.
cribriform plate A horizontal bone perforated with numerous foramina for the passage of the olfactory nerve filaments from the nasal cavity.
cricoid cartilage A firm ridge of cartilage that forms the lower part of the larynx; the first ring of the trachea and the only upper airway structure that forms a complete ring; also called the cricoid ring.
cricothyroid membrane A thin, superficial membrane located between the thyroid and cricoid cartilage that is relatively avascular and contains few nerves; the site for emergency surgical and nonsurgical access to the airway.
criminal prosecution An action instituted by the government against a private person for violation of criminal law.
crista galli A prominent bony ridge in the center of the anterior fossa to which the meninges are attached.
critical incident An event that overwhelms the ability to cope with the experience, either at the scene or later.
critical incident stress management (CISM) A process that confronts responses to critical incidents and defuses them.
critical infrastructure The external foundation in communities made up of structures and services critical in the day-to-day living activities of humans: energy sources, fuel, water, sewage removal, food, hospitals, and transportation systems.
critical minimum threshold Minimum cerebral perfusion pressure required to adequately perfuse the brain; 60 mm Hg in the adult.
critical patients Patients in either pre-morbid conditions, with major trauma, or in the peri-arrest period.
Crohn disease Inflammation of the ileum and possibly other portions of the GI tract, in which the immune system attacks portions of the intestinal walls, causing them to become scarred, narrowed, stiff, and weakened.
cross section The product of slicing an object across or perpendicular to its long axis.
cross-contamination Occurs when a person is contaminated by an agent as a result of coming into contact with another contaminated person.
cross-sectional design A data collection method in which all data at one point in time are collected, essentially serving as a “snapshot” of events and information.
cross-tolerance A process in which repeated exposure to a medication within a particular class causes a tolerance that may be “transferred” to other medications in the same class.
croup A common disease of childhood due to upper airway obstruction and characterized by stridor, hoarseness, and a barking cough.
crown The part of the tooth that is external to the gum.
crowning The appearance of the newborn’s body part (usually the head) at the vaginal opening at the beginning of labor.
crush injury An injury in which the body or part of the body is crushed, preventing tissue function and, possibly, resulting in permanent tissue damage.
crush syndrome A condition that arises after a body part that has been compressed for a significant period is released, leading to the entry of potassium and other metabolic toxins into the systemic circulation.
crystalloid solutions Solutions of dissolved crystals (for example, salts or sugars) in water; contain compounds that quickly dissociate in solution.
cubital tunnel syndrome Compression of the ulnar nerve at the tunnel along the outer edge of the elbow, causing numbness, tingling, and possible partial loss of function of the little finger and medial aspect of the ring finger.
cumulative action Several smaller doses of a particular medication capable of producing the same clinical effects as a single larger dose of that same medication.
cumulative stress reaction Prolonged or excessive stress.
cupping The cultural practice of placing warm cups on the skin to pull out illness from the body. The red, flat, rounded skin lesions are often more intensely red at the borders.
curative care Medical treatment aimed at curing an illness.
current health status A composite picture of a number of factors in a patient’s life, such as dietary habits, current medications, allergies, exercise, alcohol or tobacco use, recreational drug use, sleep patterns and disorders, and immunizations.
curved laryngoscope blade A blade designed to fit into the vallecula, indirectly lifting the epiglottis and exposing the vocal cords; also called the Macintosh blade.
Cushing reflex The combination of a slowing pulse, rising blood pressure, and erratic respiratory patterns; a grave sign for patients with head trauma or cerebrovascular accident.
Cushing syndrome A condition caused by an excess of cortisol production by the adrenal glands or by excessive use of cortisol or other similar corticosteroid (glucocorticoid) hormones.
Cushing triad Hypertension (with a widening pulse pressure), bradycardia, and irregular respirations; classic trio of findings associated with increased intracranial pressure.
cushion of safety Keeping a safe distance between your vehicle and other vehicles on any side of you.
cusps In the context of the heart, the flaps that comprise the heart valves; in the context of the oral cavity, the points at the top of a tooth.
cutaneous Pertaining to the skin.
cutaneous membrane The skin; it covers the entire surface of the body.
cyanide A colorless gas that has an odor similar to almonds, and which is a chemical asphyxiant used in many industrial processes; exposure can occur from by-products of combustion at structure fires.
cyanosis A bluish-gray skin color that is caused by inadequate levels of oxygen in the blood.
cylinders Portable, nonbulk, compressed gas containers used to hold liquids and gases. Uninsulated compressed gas cylinders are used to store substances such as nitrogen, argon, helium, and oxygen. They have a range of sizes and internal pressures.
cystic fibrosis (CF) A genetic disorder of the endocrine system that makes it difficult for chloride to move through cells; primarily targets the respiratory and digestive systems.
cytochrome P-450 system A hemoprotein involved in the detoxification of many drugs.
cytokines The products of cells that affect the function of other cells.
cytokinesis The division of the cytoplasm of a cell.
cytomegalovirus (CMV) A herpesvirus that can produce the symptoms of prolonged high fever, chills, headache, malaise, extreme fatigue, and an enlarged spleen.
cytoplasm The gel-like material that fills out a cell; it makes up most of the cell’s volume, and suspends the cell’s organelles.
cytosol The clear liquid portion of the cytoplasm.
D5W An intravenous solution made up of 5% dextrose in water.
Dalton’s law Each gas in a mixture exerts the same partial pressure that it would exert if it were alone in the same volume, and the total pressure of a mixture of gases is the sum of the partial pressures of all the gases in a mixture.
damages Compensation for injury awarded by a court.
data interpretation The process of reaching conclusions based on comparing the patient’s presentation with information from your training, education, and past experiences.
daughter cells The two identical cells produced when a parent cell divides by mitosis.
DCAP-BTLS A mnemonic for assessment in which each area of the body is evaluated for Deformities, Contusions, Abrasions, Punctures/penetrations, Burns, Tenderness, Lacerations, and Swelling.
dead space Any portion of the airway that contains air and cannot participate in gas exchange, such as the trachea and bronchi.
dead space volume (VD) Any portion of the airway that does not contain air and cannot participate in gas exchange.
deafness A complete or partial hearing loss.
DeBakey classification A classification system for aortic dissections that includes three categories.
decay A natural process in which a material that is unstable attempts to stabilize itself by changing its structure.
deceleration A negative acceleration—that is, slowing down.
decerebrate (extensor) posturing Abnormal posture characterized by extension of the arms and legs, rotation of the wrists, and toe pointing indicates pressure on the brainstem.
decision-making capacity The patient’s ability to understand and process the information you give him or her about your proposed plan of care.
decompensated shock (class III) The late stage of shock, when blood pressure is falling.
decomposition A reaction that occurs when bonds within a reactant molecule break, forming simpler atoms, molecules, or ions.
decompression illness (DCI) A term for decompression sickness (DCS) and air gas embolism (AGE).
decompression sickness (DCS) A broad range of signs and symptoms caused by nitrogen bubbles in blood and tissues coming out of solution on ascent.
decontaminate To remove or neutralize radiation, chemical, or other hazardous material from clothing, equipment, vehicles, and personnel.
decontamination corridor A controlled area within the warm zone where decontamination takes place.
decorticate (flexor) posturing Abnormal posture characterized by flexion of the arms toward the chest and extension of the legs with toes pointed; indicates pressure on the brainstem.
decussation Movement of nerves from one side of the brain to the opposite side of the body.
deep Further inside the body and away from the skin.
deep fascia A dense layer of fibrous tissue below the subcutaneous tissue; composed of tough bands of tissue that ensheath muscles and other internal structures.
deep frostbite A type of frostbite in which the affected part looks white, yellow-white, or mottled blue-white and is hard, cold, and without sensation.
deep vein thrombosis (DVT) The formation of a blood clot within the larger veins of an extremity, typically following a period of prolonged stabilization.
defamation Intentionally making a false statement, through written or verbal communication, which injures a person’s good name or reputation.
defendant In a civil suit, the person against whom a legal action is brought.
defense mechanisms Psychological ways to relieve stress; they are usually automatic or subconscious. Defense mechanisms include denial, regression, projection, and displacement.
defibrillation The use of an unsynchronized direct current electric shock to terminate ventricular fibrillation or ventricular tachycardia.
degloving A traumatic injury that results in the soft tissue of a part of the body being drawn downward like a glove being removed.
degranulate To release granules into the surrounding tissue.
dehydration Depletion of the body’s systemic fluid volume.
delayed stress reaction Reaction to stress that occurs after a stressful situation.
delirium tremens (DTs) A severe withdrawal syndrome seen in people with alcoholism who are deprived of ethyl alcohol; characterized by restlessness, fever, sweating, disorientation, agitation, and seizures; can be fatal if untreated.
delirium An acute confusional state characterized by global impairment of thinking, perception, judgment, and memory.
delta cells Cells within the pancreas that produce somatostatin, which helps to regulate the endocrine system.
delta wave The slurring of the upstroke of the first part of the QRS complex that occurs in Wolff-Parkinson-White syndrome.
delusions Thoughts, ideas, or perceived abilities that have no basis in common reality.
dementia The slow, progressive onset of disorientation, shortened attention span, and loss of cognitive function.
demobilization The process of directing responders to return to their facilities when work at a disaster or multiple-casualty incident has finished, at least for the particular responders.
dendrites The parts of neurons that receive impulses from the axon and contain vesicles for release of neurotransmitters.
denial An early response to a serious medical emergency, in which the severity of the emergency is diminished or minimized. Denial is the first coping mechanism for people who believe they are going to die.
dense connective tissue White fibrous tissue that makes up tendons and ligaments, and exists in the eyeballs and deep skin layers.
dental abscess A collection of pus that forms in the gums, facial tissue, bones, and/or neck.
dentalgia Toothache.
dentin The principal mass of the tooth, which is made up of a material that is much more dense and stronger than bone.
dependence The physical, behavioral, or emotional need for a medication or chemical in order to maintain “normal” physiologic function.
depolarization The rapid movement of electrolytes across a cell membrane that changes the cell’s overall charge. This rapid shifting of electrolytes and cellular charges is the main catalyst for muscle contractions and neural transmissions.
depolarizing neuromuscular blocker A drug that competitively binds with the acetylcholine receptor sites but is not affected as quickly by acetylcholinesterase; succinylcholine is the only one.
depressant A chemical or medication that decreases the performance of the central nervous system or sympathetic nervous system.
depressed skull fractures Result from high-energy direct trauma to a small surface area of the head with a blunt object (such as a baseball bat to the head); commonly result in bony fragments being driven into the brain, causing injury.
depression A mental health disorder characterized by a persistent mood of sadness, despair, and discouragement; it may be a symptom of many different mental and physical disorders, or it may be a disorder on its own.
depression fracture A fracture in which the broken region of the bone is pushed deeper into the body than the remaining intact bone.
dermatomes Distinct areas of skin that correspond to specific spinal or cranial nerve levels where sensory nerves enter the central nervous system.
dermis The inner layer of the skin, containing hair follicles, sweat glands, nerve endings, and blood vessels.
descending aorta One of the three portions of the aorta, it is the longest portion and extends through the thorax and abdomen into the pelvis.
descriptive A research format in which an observation of an event is made, but without attempts to alter or change it.
designated infection control officer (DICO) A person trained to ensure that proper postexposure medical treatment and counseling are provided to an exposed employee or volunteer.
desired dose The quantity of a medication that is to be administered to a patient; the drug order; usually expressed in milligrams, grams, or grains.
despair phase The second phase of an infant’s response to a situational crisis; characterized by monotonous wailing.
desquamation The continuous shedding of the dead cells on the surface of the skin.
devascularization The loss of blood to a part of the body.
developmental delay A broad term that describes an infant or child’s failure to reach a particular developmental milestone by the expected time.
developmental disability Insufficient development of a portion of the brain, resulting in some level of dysfunction or impairment.
diabetes mellitus A metabolic disorder in which the ability to metabolize carbohydrates (sugar) is impaired due to lack of insulin or failure of the cells to use insulin properly.
diabetic ketoacidosis (DKA) A form of acidosis in uncontrolled diabetes in which certain acids accumulate when insulin is not available.
diabetic retinopathy A condition associated with diabetes, in which the small blood vessels of the retina are affected; can eventually lead to blindness.
dialysis A medical process by which a patient’s blood is cleansed of excess toxins by passing through a special machine.
diapedesis A process whereby leukocytes leave blood vessels to move toward tissue where they are needed most.
diaphoresis Excessive sweating; it is often associated with shock.
diaphragm Large skeletal muscle that plays a major role in breathing and separates the chest cavity from the abdominal cavity.
diaphragmatic hernia Passage of loops of bowel with or without other abdominal organs, through a developmental defect in the diaphragm muscle; occurs as the bowel from the abdomen “herniates” upward through the diaphragm into the chest (thoracic) cavity.
diaphysis The shaft of a long bone.
diarrhea Liquid stool.
diastasis An increase in the distance between the two sides of a joint.
diastole The period of ventricular relaxation during which the ventricles passively fill with blood.
diastolic pressure The result of residual pressure in the circulatory system while the left ventricle is relaxing (ie, in diastole).
dieffenbachia A common houseplant that resembles “elephant ears”; ingestion leads to burns of the mouth and tongue and, possibly, paralysis of the vocal cords and nausea and vomiting; in severe cases, may be edema of the tongue and larynx, leading to airway compromise.
diencephalon The part of the brain between the brainstem and the cerebrum that includes the thalamus, subthalamus, and hypothalamus.
differential diagnosis The process of weighing the probability of one disease versus other diseases by comparing clinical findings that could account for a patient’s illness.
differential field diagnosis The short list of the potential causes of the patient’s presenting condition.
differentiation The process of specialization of a cell.
diffuse axonal injury (DAI) Diffuse brain injury that is caused by stretching, shearing, or tearing of nerve fibers with subsequent axonal damage.
diffuse brain injury Any injury that affects the entire brain.
diffusion A process in which molecules move from an area of higher concentration to an area of lower concentration.
digestion The mechanical and chemical breakdown of the large molecules in food into small molecules that can be absorbed in the GI tract and converted to energy for cellular function.
digital arteries The arteries that supply blood to the fingers and toes.
digital intubation A method of intubation that involves directly palpating the glottic structures and elevating the epiglottis with the middle finger while guiding the endotracheal tube into the trachea by using the sense of touch.
digital radio The microwave transmission of digital signals through space or the atmosphere instead of transmission by radio waves.
digitalis preparations The drugs used in the treatment of congestive heart failure and certain atrial dysrhythmias.
dilated cardiomyopathy (DCM) A condition in which the heart becomes weakened and enlarged, making it less efficient and causing a negative impact to the pulmonary, hepatic, and other systems.
diluent A solution (usually water or normal saline) used for diluting a medication.
dilution A type of decontamination method that uses copious amounts of water to flush the contaminant from the skin or eyes.
diploid Cells that carry two of each of the 23 chromosomes—one from the father and one from the mother.
diplopia Double vision.
direct contact Exposure to or transmission of a communicable disease from one person to another by physical contact.
direct laryngoscopy Visualization of the airway with a laryngoscope.
directed area An area away from the command post or emergency operations center, considered by engineering expertise to be a safe place to stage until directed otherwise.
dirty bomb Name given to a bomb that is used as a radiologic dispersal device (RDD).
disaccharides A simple sugar comprised of two monosaccharides.
disaster A widespread event that disrupt community resources and functions, in turn threatening public safety, lives, and property.
disaster management A planned, coordinated response to a disaster that involves cooperation of multiple responders and agencies and enables effective triage and provision of care according to triage decisions.
disease vector An animal that, once infected, spreads a disease to another animal.
disequilibration syndrome A condition characterized by nausea, vomiting, headache, and confusion, which results when, as a consequence of dialysis, water initially shifts from the bloodstream into the cerebrospinal fluid, mildly increasing intracranial pressure.
disinfectants Chemicals used on nonliving objects to kill organisms; toxic to living tissues.
disinfection The killing of pathogenic agents by direct application of chemicals.
dislocation The displacement of a bone from its normal position within a joint.
disorganization A condition in which a person is characterized by uncontrolled and disconnected thought, is usually incoherent or rambling in speech, and may or may not be oriented to person and place.
disorientation A condition in which a person may be confused about his or her identity, the location, and the time of day; one of the ways in which various conditions such as schizophrenia or organic brain syndrome may present.
dispatch To send to a specific destination or to send on a task.
displaced fracture A break in which the ends of the fractured bone move out of their normal positions.
displacement Redirection of an emotion from yourself to another person.
disposal A type of decontamination in which as much clothing and equipment as possible is disposed of to reduce the magnitude of the problem.
dissection In reference to blood vessels, an aneurysm, or bulge, formed by the separation of the layers of an arterial wall.
disseminated intravascular coagulation (DIC) A life-threatening condition commonly found in severe trauma.
dissemination The means with which a terrorist will spread a disease—for example, by poisoning the water supply or aerosolizing the agent into the air or ventilation system of a building.
dissociates Process of losing a hydrogen atom in the presence of water. Acids are classified as strong or weak, depending on how completely they dissociate.
distal Farther from the trunk or nearer to the free end of the extremity.
distal convoluted tubule (DCT) Connects with the kidney’s collecting tubules.
distraction injury An injury that results from a force that tries to increase the length of a body part or separate one body part from another.
distribution The movement and transportation of a medication throughout the bloodstream to tissues and cells and, ultimately, to its target receptor.
distributive shock The type of shock that occurs when there is widespread dilation of the resistance vessels (small arterioles), the capacitance vessels (small venules), or both.
diuresis The production of large amounts of urine by the kidney.
diuretic A chemical that increases urinary output.
diverticulitis Inflammation of pouches in the colon; these pouches form as a result of difficulty moving feces through the colon. Once the pouches are formed, bacteria can become trapped in the pouch, leading to inflammation and infection.
diverticulum A weak area in the colon that begins to have small outcroppings that turn into pouches; plural is diverticula.
do not resuscitate (DNR) order A type of advance directive that describes which life-sustaining procedures should be performed in the event of a sudden deterioration in a patient’s medical condition.
domestic terrorism Terrorism that is carried out by native citizens against their own country.
dorsal The posterior surface of the body, including the back of the hand.
dorsal respiratory group (DRG) A portion of the medulla oblongata where the primary respiratory pacemaker is found.
dorsalis pedis artery The artery on the anterior surface of the foot between the first and second metatarsals.
dorsiflex To bend the foot or hand backward.
dose effect The principle that the longer a hazardous material is in contact with the body or the greater the concentration, the greater the effect will most likely be.
dose-response curve A graphic illustration of the response of a drug according to the dose administered.
dosing The specified amount of a medication to be given at specific intervals.
DOT KKK 1822 Federal standards that regulate the design and manufacturing guidelines of emergency ambulances.
Down syndrome A genetic chromosomal defect that can occur during fetal development and that results in mental retardation and certain physical characteristics, such as a round head with a flat occiput and slanted, wide-set eyes.
down-regulation The process in which a mechanism reducing available cell receptors for a particular medication results in tolerance.
dressing Material used to directly cover a wound.
drift A finding that when the operator lets go of the steering wheel, a vehicle consistently wanders left or right.
drip chamber The area of the administration set where fluid accumulates so that the tubing remains filled with fluid.
dromotropic effect The effect on the velocity of conduction.
droplet transmission The transmission of an infectious agent by inhalation of relatively large particles generated when an infected person coughs or sneezes; these particles travel a short distance through the air before falling to the ground.
drowning The process of experiencing respiratory impairment from submersion or immersion in liquid.
drug Substance that has some therapeutic effect (such as reducing inflammation, fighting bacteria, or producing euphoria) when given in the appropriate circumstances and in the appropriate dose.
drug abuse Any use of drugs that causes physical, psychological, economic, legal, or social harm to the user or others affected by the user’s behavior.
drug addiction A chronic disorder characterized by the compulsive use of a substance that results in physical, psychological, or social harm to the user who continues to use the substance despite the harm.
drug interactions Any potential effects that a medication may have when administered in conjunction or in the presence of another medication already in the patient’s system, a medication delivery device, or fluid.
drug reconstitution Injecting sterile water or saline from one vial into another vial containing a powdered form of the drug.
drums Barrel-like nonbulk storage vessels used to store a wide variety of substances, including food-grade materials, corrosives, flammable liquids, and grease. Drums may be constructed of low-carbon steel, polyethylene, cardboard, stainless steel, nickel, or other materials.
dry bulk cargo tanks Tanks designed to carry dry bulk goods such as powders, pellets, fertilizers, or grain. Such tanks are generally V-shaped with rounded sides that funnel toward the bottom.
due process A right to a fair procedure for a legal action against a person or agency; has two components: Notice and Opportunity to be Heard.
due regard Driving with awareness and responsibility for other drivers on the roadways when you are operating an ambulance in the emergency mode, and making sure that other drivers are aware of your approach.
Dunphy sign Severe abdominal pain in the right lower quadrant with coughing; a method for evaluating a patient for peritonitis.
duodenum The first part of the small intestine.
DuoDote A nerve agent antidote kit that contains a single injection of both atropine (2 mg) and 2-PAM chloride (pralidoxime chloride) (600 mg).
duplex Radio system using more than one frequency to permit simultaneous transmission and reception.
dura mater The outermost layer of the three meninges that enclose the brain and spinal cord; it is the toughest meningeal layer.
duration of action Three values are given: (1) onset: the estimated amount of time it will take for the medication to enter the body/system and begin to take effect, (2) peak effect: the estimated amount of time it will take for the medication to have its greatest effect on the patient/system, and (3) duration: the estimated amount of time that the medication will have any effect on the patient/system.
duration of effect The time a medication concentration can be expected to remain above the minimum level needed to provide the intended action.
dust suffocation A phenomenon that can occur during an earthquake, in which particles of dust and debris are loosened and released into the air, producing a toxic and hypoxic atmosphere.
duty Legal obligation of public and certain other ambulance services to respond to a call for help in their jurisdiction.
dysarthria A speech disorder caused by neuromuscular disturbance that causes speech to become slow and slurred.
dysconjugate gaze Paralysis of gaze or lack of coordination between the movements of the two eyes.
dysfunctional uterine bleeding Abnormal vaginal bleeding that is irregular and is not caused by pregnancy, infection, or tumor.
dyslipidemia An excessive level of lipids (fats) circulating in the blood, increasing the risk of atherosclerosis and coronary artery disease.
dysmenorrhea Painful menstruation.
dysphagia Difficulty swallowing.
dysphonia Difficulty speaking.
dysplasia An alteration in the size, shape, and organization of cells.
dyspnea Difficult or labored breathing.
dysrhythmias Disturbances in the cardiac rhythm.
dystonia Contractions of body into bizarre positions.
dystonic Pertaining to voluntary muscle movements that are distorted or impaired because of abnormal muscle tone.
ear canal The cavity leading from the exterior atmosphere to the tympanum.
early adults Persons who are 18 to 40 years of age.
ecchymosis Localized bruising or blood collection within or under the skin to produce a “black-and-blue” mark.
echolalia Meaningless echoing of the interviewer’s words by the patient.
eclampsia Seizures that result from severe hypertension in a pregnant woman.
ecstasy A drug officially named methylenedioxymethamphetamine (MDMA) that is sometimes used to facilitate date rape; a methamphetamine derivative with hallucinogenic properties; street names include XTC, Adam, X, lover’s speed, and clarity.
ectopic foci Sites of generation of electrical impulses other than normal pacemaker cells.
ectopic pregnancy A pregnancy in which the ovum implants somewhere other than the uterine endometrium.
effacement Thinning and shortening of the cervix; this is a normal process that occurs as the uterus contracts.
efferent arteriole The structure in the kidney where blood drains from the glomerulus.
efferent nerves Nerves that leave the brain through the peripheral nervous system and convey commands to other parts of the body.
efficacy In a pharmacologic context, the ability of a medication to produce the desired effect.
egophony A test of decreased breath sounds performed by placing the diaphragm of the stethoscope over the area in question while the patient says “ee”; an “ay” sound indicates lung consolidation.
ejaculation The forcing of semen through the urethra to outside of the body.
ejaculatory duct A structure formed by the vasa deferentia uniting with the duct of a seminal vesicle; this type of duct passes through the prostate gland to empty into the urethra.
ejection click A high-pitched heart sound that occurs just after the S1 sound.
ejection fraction (EF) The percentage of blood that leaves the heart each time it contracts.
elastic cartilage A flexible type of cartilage that provides framework for the ears and larynx.
elastin A protein that gives the skin its elasticity.
elective abortion Intentional expulsion of the fetus.
electrical conduction system In the heart, the specialized cardiac tissue that initiates and conducts electric impulses; includes the SA node, internodal conduction pathways, atrioventricular junction, atrioventricular node, bundle of His, and the Purkinje network.
electrical energy The energy delivered in the form of high voltage.
electrolytes Salt or acid substances that become ionic conductors when dissolved in a solvent (ie, water); chemicals dissolved in the blood; used in the body to perform certain critical metabolic functions.
electrons Single, negatively charged particles that revolve around the nucleus of an atom.
elements Fundamental substances, such as carbon, hydrogen, and oxygen, that compose matter.
elevated A threat level in which a terrorist event is suspected, but there is no specific information about its timing or location.
elimination In a pharmacologic context, the removal of a medication or its by-products from the body.
emancipated minor A person who is under the legal age in a given state, but is legally considered an adult because of other circumstances.
embryo The fetus in the earliest stages after fertilization.
emergency decontamination The process of removing the bulk of contaminants off of a victim without regard for containment. It is used in potentially life-threatening situations, without the formal establishment of a decontamination corridor.
emergency medical dispatch First aid instructions given by specially trained dispatchers to callers over the telephone while an ambulance is en route to the call.
emergency medical dispatcher (EMD) A person who receives information and relays that information in an organized manner during the emergency.
emergency medical services (EMS) A health care system designed to bring immediate on-scene care to those in need along with transport to a definitive medical care facility.
emergency operations center (EOC) A central command and control facility, found at all government levels, responsible for strategic overview; tactical decisions are left to incident commanders.
emission The movement of sperm cells from the testes, and secretions of the prostate gland and seminal vesicles, into the urethra.
emotional abuse A form of abuse that may be verbal (such as ridicule, threats, blaming, or humiliation), or nonverbal (caregiver ignores the victim or isolates the victim from others); causes a substantial change in the victim’s behavior, emotional response, cognitive function, or may manifest as a variety of mental illnesses.
emphysema The infiltration of any tissue by air or gas; a chronic obstructive pulmonary disease characterized by distention of the alveoli and destructive changes in the lung parenchyma.
EMTALA The Emergency Medical Treatment and Active Labor Act enacted in 1986 to combat the practice of patient dumping (hospitals refusing to admit seriously ill patients or women in labor who could not pay, forcing EMS providers to dump the patients at another hospital). EMTALA regulates hospitals that receive Medicare funding and severely fines hospitals or doctors who violate its provisions.
encapsulated nerve endings Nerve endings in the skin surrounded by connective tissue that measure mechanical inputs.
encoded A message is put into a code before it is transmitted.
endemic Consistently present or prevalent in a population or geographic area.
endocarditis Inflammation of the endocardium.
endocardium The thin membrane lining the inside of the heart.
endochondrial ossification The process of bone formation.
endocrine glands Glands that secrete or release chemicals that are used inside the body; these lack ducts and release hormones directly into the surrounding tissue and blood.
endocrine hormones The hormones that are carried to their target or cell group in the bloodstream.
endocrine system The complex message and control system that integrates many body functions, including the release of hormones.
endogenous Originating from within the organism (body).
endolymph The fluid containing nerve receptors that resides inside the membranous labyrinth. Sound waves converted into pressure waves are transmitted through this fluid to the auditory nerves.
endometriosis A condition in which endometrial tissue grows outside the uterus.
endometritis An inflammation of the endometrium that often is associated with a bacterial infection.
endometrium The innermost layer of the uterine wall.
endoscopy Insertion of a flexible fiberoptic tube into the esophagus to visualize, remove, or repair damaged or diseased tissue.
endosteum The inner lining of a hollow bone.
endothelial cells Specific types of epithelial cells that line the blood vessels.
endotoxin A toxin released by some bacteria when they die.
endotracheal (ET) tube A tube that is inserted into the trachea for definitive airway maintenance; equipped with a distal cuff, proximal inflation port, a 15/22-mm adapter, and centimeter markings on the side.
endotracheal intubation Inserting an endotracheal tube through the glottic opening and sealing the tube with a cuff inflated against the tracheal wall.
end-stage renal disease (ESRD) A condition in which the kidneys have lost all ability to function, and toxic waste materials build up in the patient’s blood; occurs after acute or chronic renal failure.
end-tidal carbon dioxide The carbon dioxide contained in the last few milliliters of exhaled air; the unit of measure is a percentage.
end-tidal CO2 (ETCO2) monitors Devices that detect the presence of carbon dioxide in exhaled air.
enhanced 9-1-1 system An emergency call-in system in which additional information such as the phone number and location of the caller is recorded automatically through sophisticated telephone technology and the dispatcher need only confirm the information on the screen.
enteral medications Medication administration that involves the medication passing through a portion of the gastrointestinal tract.
Enterococcus A common, normal organism of the gastrointestinal (GI) tract, urinary tract, and genitourinary tract that can be pathogenic and become resistant to vancomycin.
entrapment A condition in which a patient is trapped by debris, soil, or other material and is unable to extricate himself or herself.
entry wound The point at which a penetrating object enters the body.
envenomation The injecting of venom via a bite or sting.
environmental emergencies Medical conditions caused or exacerbated by the weather, terrain, or unique atmospheric conditions such as high altitude or underwater.
enzymes Substances designed to speed up the rate of specific biochemical reactions.
eosinophils White blood cells with a major role in allergic reactions and bronchoconstriction during an asthma attack; make up approximately 1% to 3% of leukocytes.
ependymal cells Neuroglia that cover specialized brain parts and form inner linings enclosing spaces inside the brain and spinal cord; they secrete cerebrospinal fliod.
epicardium The thin membrane lining the outside of the heart; also referred to as the visceral pericardium.
epidemic An outbreak of disease that substantially exceeds what is expected based on recent experience.
epidermis The outermost layer of the skin that acts as the body’s first line of defense.
epididymides Tightly coiled tubes connected to ducts within a testis; they become the vas deferens.
epididymitis An infection that causes inflammation of the epididymis along the posterior border of the testis; a possible complication of male urinary tract infection.
epidural hematoma An accumulation of blood between the skull and dura.
epigastric The region of the abdomen directly inferior to the xyphoid process and superior to the umbilicus.
epiglottis A leaf-shaped cartilaginous structure that closes over the trachea during swallowing.
epiglottitis Inflammation of the epiglottis.
epinephrine A hormone produced by the adrenal medulla that has a vital role in the function of the sympathetic nervous system.
epiphyseal plate The growth plate of a bone; a major site of bone development during childhood.
epiphysis The growth plate of a long bone; also called the epiphyseal plate.
episiotomy An incision in the perineal skin made to prevent tearing during childbirth.
epistaxis Nosebleed.
epithelial membranes Membranes that cover body surfaces and line body cavities.
epithelial tissues Body tissues that cover organs, form the inner lining of cavities, and line hollow organs.
epithelialization The formation of fresh epithelial tissue to heal a wound.
epithelium A type of tissue that covers all external surfaces of the body.
Erb palsy Lack of movement at the shoulder due to nerve injury resulting from the stretching of the cervical nerve roots (C5 and C6 most commonly) during delivery of the newborn’s head during birth. The effect is usually transient, but can be permanent.
erection The swelling and elongation of the penis in preparation for sexual intercourse.
erythema Reddening of the skin.
erythrocytes Red blood cells.
erythropoiesis The process by which red blood cells are made.
escharotomy A surgical cut through the eschar or leathery covering of a burn injury to allow for swelling and minimize the potential for development of compartment syndrome in a circumferentially burned limb or the thorax.
esophageal detector device A bulb or syringe that is attached to the proximal end of the endotracheal (ET) tube; a device used to confirm proper ET tube placement.
esophagogastric varices Dilated blood vessels of the esophagus, commonly caused by difficulty in blood flow through the liver; the presence of these can lead to vessel rupture.
esophagus A collapsible tube that extends from the pharynx to the stomach; contractions of the muscle in the wall of the esophagus propel food and liquids through it to the stomach.
estrogen A hormone released from the ovaries that stimulates the uterine lining during the menstrual cycle.
ethical A behavior expected by a person or group following a set of rules.
ethics A set of values in society that differentiates right from wrong.
etomidate A nonnarcotic, nonbarbiturate hypnoticsedative drug; also called Amidate.
eustachian tube A branch of the internal auditory canal that connects the middle ear to the oropharynx.
evacuation The removal or relocation of people who may be affected by an approaching release of a hazardous material.
evaluation Collection of the methods, skills, and activities necessary to determine whether a service or program is needed, likely to be used, conducted as planned, and actually helps people.
evaporation The conversion of a liquid to a gas.
evidence-based practice The use of practices that have been proven to be effective in improving patient outcomes.
evisceration Displacement of an organ outside the body.
exchange reaction A chemical reaction where parts of the reacting molecules are shuffled around to produce new products.
excitability The property that allows cells to respond to an electrical impulse.
exercise-associated hyponatremia A condition due to prolonged exertion in hot environments coupled with excessive hypotonic fluid intake that leads to nausea, vomiting, and, in severe cases, mental status changes and seizures (also known as exertional hyponatremia).
exertional heatstroke A serious type of heatstroke usually affecting young and fit people exercising in hot and humid conditions.
exhalation Passive movement of air out of the lungs; also called expiration.
exit wound The point at which a penetrating object leaves the body, which may or may not be in a straight line from the entry wound.
exocrine glands Glands that excrete chemicals for elimination.
exocrine hormones The hormones that are secreted through ducts into an organ or onto epithelial surfaces.
exogenous Originating outside the organism (body).
exophthalmos Protrusion of the eyes from the normal position within the socket.
exotoxin A toxin secreted by living cells to aid in the death and digestion of other cells.
expiratory reserve volume The amount of air that can be exhaled following a normal exhalation; average volume is about 1,200 mL.
expressed consent A type of informed consent that occurs when the patient does something, either through words or by taking some sort of action, that demonstrates permission to provide care.
expressive aphasia Damage or loss in the ability to speak.
extension The straightening of a joint.
external auditory canal The area in which sound waves are received from the auricle (pinna) before they travel to the eardrum; also called the ear canal.
external ear One of three anatomic parts of the ear; it contains the pinna, the ear canal, and the external portion of the tympanic membrane.
external jugular (EJ) vein Large neck vein that is lateral to the carotid artery.
external respiration The exchange of gases between the lungs and the blood cells in the pulmonary capillaries; also called pulmonary respiration.
external rotation Rotating an extremity at its joint away from the midline.
extracellular fluid (ECF) Fluid outside of the cell, in which most of the body’s supply of sodium is contained; accounts for 15% of body weight.
extravasation Seepage of blood and medication into the tissue surrounding the blood vessel.
extrication supervisor In incident command, the person appointed to determine the type of equipment and resources needed for a situation involving extrication or special rescue; also called the rescue supervisor.
extrinsic muscles Referring to the eye; six muscles that attach to the exterior of the globe and are controlled by the cranial nerves.
extubation The process of removing the tube from an intubated patient.
eyelash reflex Contraction of a patient’s lower eyelid when the upper eyelashes are gently stroked; a fairly reliable indicator of the presence or absence of an intact gag reflex.
EZ-IO A hand-held, battery-powered driver to which a special IO needle is attached; used for insertion of the IO needle into the proximal tibia of children and adults.
facet joint The joint on which each vertebra articulates with adjacent vertebrae.
face-to-face intubation Performing intubation at the same level as the patient’s face; used when the standard position is not possible. In this position, the laryngoscope is held in the provider’s right hand and the endotracheal tube in the left.
facial nerve The seventh cranial nerve; supplies motor activity to all muscles of facial expression and anterior two thirds of the tongue; and also relates to the sense of taste and cutaneous sensation to the external ear, tongue, and palate.
facilitated diffusion Process whereby a carrier molecule moves substances in or out of cells from areas of higher to lower concentration.
factitious disorder A disorder in which a person wishes to be sick and intentionally produces or feigns physical or psychological signs or symptoms. Symptoms are under voluntary control, with no obvious physiologic reason.
Fahrenheit scale A scale for measuring temperature where water freezes at 32° and boils at 212°.
fallopian tube The anatomic structure that connects each ovary with the uterus and provides a passageway for the ova.
false imprisonment The intentional and unjustified detention of a person against his or her will.
false lumen A term used to describe an area that a device was not intended to be inserted into—for example, when a tracheostomy tube is inserted into an area other than the trachea.
fascia A sheet or band of tough fibrous connective tissue that covers, supports, and separates muscles, and which also covers arteries, veins, tendons, and ligaments.
fascicular block Disease or ischemia of either of the anterior and posterior fascicles of the electrical conduction system of the heart; also called hemiblock.
fasciculation Brief, uncoordinated, visible twitching of small muscle groups; may be caused by the administration of a depolarizing neuromuscular blocking agent (namely, succinylcholine).
fasciitis Inflammation of the fascia.
fasciotomy A surgical procedure that cuts away fascia to relieve pressure.
FAST1 A sternal IO device used in adults; stands for First Access for Shock and Trauma.
fatigue fractures Fractures that result from multiple compressive loads.
feculent Smelling of feces.
Federal Communications Commission (FCC) The federal agency that has jurisdiction over interstate and international telephone and telegraph services and satellite communications, all of which may involve EMS activity.
feedback inhibition Negative feedback resulting in the decrease of an action in the body.
feet of seawater (fsw) An indirect measure of pressure under water, equal to one atmosphere absolute (ATA).
femoral artery The principal artery of the thigh, a continuation of the external iliac artery. It supplies blood to the lower abdominal wall, external genitalia, and legs. It can be palpated in the groin area.
femoral head The proximal end of the femur, articulating with the acetabulum to form the hip joint.
femoral shaft fractures A break in the diaphysis of the femur.
femoral vein A continuation of the saphenous vein that drains into the external iliac vein.
femur The proximal bone of the leg that extends from the pelvis to the knee.
fenestrated Having perforations, holes, or openings.
fetal macrosomia A situation in which a fetus is large, usually defined as weighing more than 4,500 grams or almost 9 pounds; also known as “large for gestational age.”
fetal transition The process through which the fluid in the fetal lungs is replaced with air, the ductus arteriosus constricts, and the newborn begins adequate oxygenation of its own blood.
fetus The developing, unborn infant inside the uterus.
fibrin A whitish, filamentous protein formed by the action of thrombin on fibrinogen; the protein that polymerizes (bonds) to form the fibrous component of a blood clot.
fibrinogen A plasma protein that is important for blood coagulation.
fibrinolysis The process of dissolving blood clots.
fibrinolysis cascade The breakdown of fibrin in blood clots and the prevention of the polymerization of fibrin into new clots.
fibrinolytic therapy The therapy that uses medications that act to dissolve blood clots.
fibroblast A star-shaped fixed cell that produces fibers via protein secretion into the extracellular matrix.
fibrocartilage A tough type of cartilage that absorbs shock in the spinal column, knees, and pelvic girdle.
fibrous joints The joints that contain dense fibrous tissue and allow for no motion.
fibula The long bone on the lateral aspect of the lower leg.
Fick principle A principle that states the movement and use of oxygen in the body is dependent on an adequate concentration of inspired oxygen, appropriate movement of oxygen across the alveolar-capillary membrane into the arterial bloodstream, adequate number of red blood cells to carry the oxygen, proper tissue perfusion, and efficient off-loading of oxygen at the tissue level.
field impression A determination of what you think is the patient’s current problem, usually based on the patient history and the chief complaint.
fight-or-flight syndrome A physiologic response to a profound stressor that helps a person deal with the situation at hand; features increased sympathetic tone and results in dilation of the pupils, increased heart rate, dilation of the bronchi, mobilization of glucose, shunting of blood away from the gastrointestinal tract and cerebrum, and increased blood flow to the skeletal muscles.
filtration Use of hydrostatic pressure to force water or dissolved particles through a semipermeable membrane.
finance In incident command, the position in an incident responsible for accounting of all expenditures.
first stage of labor The stage of labor that begins with the onset of regular labor pains, crampy abdominal pains, during which the uterus contracts and the cervix effaces.
first-degree heart block A partial disruption of the conduction of the depolarizing impulse from the atria to the ventricles, causing prolongation of the PR interval.
first-order elimination The process in which the rate of elimination is directly influenced by plasma levels of a substance.
fistula A surgical connection between an artery and a vein.
flail chest An injury that involves two or more adjacent ribs fractured in two or more places, allowing the segment between the fractures to move independently of the rest of the thoracic cage.
flame burn A thermal burn caused by flames touching the skin.
flammable range An expression of a fuel/air mixture, defined by upper and lower limits, that reflects an amount of flammable vapor mixed with a given volume of air.
flange The part of a tracheostomy tube that is used to stabilize the tube to the patient’s neck.
flash burn An electrothermal injury caused by arcing of electric current.
flash chamber The area of an IV catheter that fills with blood to help indicate when a vein is cannulated.
flash point The minimum temperature at which a liquid or a solid releases sufficient vapor to form an ignitable mixture with air.
flat affect The absence of emotion; appearing to feel no emotion at all.
flat bones Bones that are thin and broad, such as the scapula.
flexion The bending of a joint.
flexion injury A type of injury that results from forward movement of the head, typically as the result of rapid deceleration, such as in a car crash, or with a direct blow to the occiput.
flexor tenosynovitis of the hand A closed-space infection of the hand.
flight of ideas Accelerated thinking in which the mind skips very rapidly from one thought to the next.
fluid balance The process of maintaining homeostasis through equal intake and output of fluids.
focal brain injury A specific, grossly observable brain injury.
focused assessment A type of physical assessment that is typically performed on patients who have sustained an isolated injury or on responsive medical patients. This type of examination is based on the chief complaint and focuses on one body system or part.