Abdomen – the portion of the trunk below the diaphragm.
Abortion – the expulsion or removal of an embryo or foetus from the uterus at a time when it is incapable of independent survival.
Abortifacient – a substance that will induce an abortion or miscarriage.
Absorption – the uptake of fluids and other substances by the tissues.
Acid – sharp or sour taste; also chemically, an acid combines with a base to form a salt.
Acid-base balance – the levels of carbonic acid and bicarbonate in the blood must be maintained at a constant ratio of 1:20. Any disturbance results in a state of acidosis or alkalosis in the blood and tissues. This may be caused by lung or kidney problems, as these organs both play an important role in the regulation of the body’s acid-base balance.
Acidosis – a condition in which the acidity of the body fluids is abnormally high, caused by failure of the mechanisms, in the lungs or kidneys, which normally maintain the acid-base balance.
Active – effective or potent, ready.
Activate – to make active, to stimulate or increase biological activity.
Acute – an illness of rapid onset, severe symptoms and brief duration.
-aemia – relating to a biochemical condition of the blood.
Adeno – relating to a gland.
Adipose tissue – fibrous connective tissue packed full of fat cells.
Adsorption – the adhesion of a thin layer of molecules of a substance to the surface of a solid or liquid.
Aerobe – an organism that requires oxygen for life and growth.
Agent – something that causes an effect.
Agranulocytosis – a severe deficiency of certain blood cells, the neutrophils, due to damage to the bone marrow, where blood cells are made; may be caused by toxic drugs or chemicals.
Albumin – a water-soluble protein, made by the liver and present in blood plasma. Can indicate kidney or heart disease if found in the urine.
Alcohol – a type of organic chemical in which a hydroxyl group (-OH) is substituted for a hydrogen atom.
The alcohol we drink is ethyl alcohol, C2H5OH.
Other alcohols, such as methyl alcohol, CH3OH, are poisonous.
-algia – a suffix meaning pain.
Alkali – a basic substance that combines with an acid to form a salt.
Alkaloid – a nitrogen-containing substance produced by a plant. They are many and varied, and have potent effects on the body. Many alkaloids are used as drugs, such as morphine, quinine and atropine.
Alkalosis – an illness in which the blood and tissues become too alkaline, due to disturbance of the acid-base balance.
-amine – an organic compound containing an amino (-NH2) group, e.g. histamine.
Amino acids – the fundamental components of proteins.
Amphetamine – a very addictive type of stimulant drug, which lessens fatigue and produces a feeling of mental alertness and well-being.
Anabolic – building up from simple to complex substances.
Anaemia – a reduction in the quantity of haemoglobin in the blood. There are many causes but the symptoms are tiredness and breathlessness, pallor and poor resistance to infection.
Anaerobe – an organism which can live and grow without oxygen.
Anaphylactic shock – an extreme and generalised allergic reaction in which there is widespread release of histamine, which causes massive swelling, resulting in breathing difficulties, heart failure, circulatory collapse and sometimes death.
Ankylostomiasis – a disease caused by a widely distributed parasitic hookworm that lives in the small intestine of humans in Europe, America, Africa and Asia.
Anorectic – a drug that reduces the appetite.
Anorexia – loss of appetite.
Antagonism – having the opposite effect.
Anti- – against.
Antibody – a special type of protein in the blood; a globulin which circulates and attacks antigens to render them harmless. An essential part of our immune system.
Anticoagulant – a drug that prevents blood from clotting.
Anticonvulsant – a drug that prevents convulsions, used in treating epilepsy.
Antidote – a drug that counteracts the effects of poison.
Antigen – any substance the body regards as foreign or potentially dangerous, against which it produces an antibody.
Anti-inflammatory – reduces or prevents inflammation.
Antipyretic – reduces fever by lowering body temperature.
Antiserum – a fluid that contains antibodies.
Antitoxin – an antibody produced by the body to counteract a toxin.
Aplastic anaemia – anaemia due to bone marrow failure.
Apoplexy – a stroke.
Argyria – deposition of silver in the skin and other tissues, resulting from chronic exposure.
Arthritis – inflammation of one or more joints.
Aspirate – to withdraw fluid from the body by suction.
Asphyxia – suffocation.
ATP – adenosine triphosphate, a compound that acts as an energy store within body cells, which is needed for muscular contraction.
Atrophy – wasting away.
Auxins – plant hormones or growth substances.
Base – reacts with an acid to produce a salt.
Bacteria – a type of micro-organism, widely distributed and the cause of many illnesses and infections.
Barbiturate – a highly addictive sedative drug.
Bends – compressed air illness, suffered by divers. If a diver surfaces too quickly, nitrogen that has dissolved in the bloodstream forms bubbles, causing pain in the joints; this causes damage as it leads to blocking the small blood vessels of the body, including those in the brain. This condition can be lethal without prompt treatment in a decompression chamber.
Benign – harmless.
Bilharziasis – schistosomiasis, an illness caused by a parasitic blood fluke. The larval stage is transmitted by water-snails in sewage-contaminated water in the Americas, Africa and Asia.
Blood pressure – the pressure of blood against the main arteries. Low blood pressure caused by shock or circulatory failure is called hypotension. In contrast, hypertension is raised blood pressure and if untreated can result in a stroke and other vascular damage.
Bound – some substances, such as metals, become bound to chelators and so are effectively removed, as they are then no longer available in the free state to damage organs; similarly some drugs are largely circulating in the body in the bound form and the drug’s action is due only to the small amount that is circulating in the free state.
Brimstone – the old name for sulphur.
Buffer – a substance or solution that maintains the acidity or alkalinity (pH) even when diluted or when more acid or alkali is added. The bicarbonate system is the main buffer in the body.
Calcification – build-up of calcium in the tissues.
Calculus/calculi – a stone, or stones, formed in the body, usually composed largely of calcium phosphate or oxalate; they form in the gall bladder, the kidneys and bladder and even sometimes in the salivary glands. They are very painful and need to be removed surgically, although today they are usually broken up into tiny pieces using ultrasonic devices.
Cancer – a malignant tumour or growth, arising from the abnormal and uncontrolled division of cells, which then destroys the surrounding tissues.
Cantharides – Spanish Fly, the dried bodies of the blister beetle, Lytta vesicatoria; contains cantharadin, a toxic and highly irritant chemical, which on contact causes blistering of the skin.
Carbohydrate – a source of energy, such as sugars and starch, manufactured by plants and an essential part of the diet in humans.
Carbolic acid – an old-fashioned disinfectant, no longer in use, now called phenol.
Carboxyhaemoglobin – this substance is formed when carbon monoxide combines with haemoglobin in the blood. The blood is then incapable of transporting oxygen to the tissues; this is the cause of death of carbon monoxide poisoning.
Carcinogen – any substance, which when exposed to living tissue, causes cancer.
Carcinoma – cancer.
Cardiac – relating to, or affecting, the heart.
Cardiomyopathy – chronic disorder affecting the muscles of the heart.
Cardiovascular – pertaining to the heart and blood supply.
Carminative – relieves flatulence; used for gastric discomfort and colic.
Catabolic – breaking down complex substances into simple ones.
Cataract – an opacity in the lens of the eye which causes blurred vision and ultimately blindness.
Cathartic – laxative.
Cellular respiration – see Electron Transport.
Chelator – a chemical that binds on to metals; chelators are used in the treatment of poisoning. Some form the active centres of enzymes.
Cholesterol – a fat-like material present in the blood and most other tissues of the body, especially the nervous system.
Chronic – long-standing; frequently a disease state of long duration with gradual onset and very slow changes.
-cidal – causes death.
Circulation – the heart and blood supply, arteries, veins and capillaries.
CJD – Creutzfeldt-Jakob Disease. A rare, rapidly progressive, neurological disease for which there is, as yet, no effective treatment.
Clotting /clotting factors – solidifying of blood; chemicals essential to stop bleeding. See Coagulate and Coagulation factors.
Coagulate – the process of changing blood from liquid to solid by clotting.
Coagulation factors – a number of chemicals which are all essential for the coagulation of blood. Some people, such as haemophiliacs, lack one or more of these factors and so their blood is unable to clot without an injection of the missing clotting factors.
Co-enzyme – an organic compound that plays an essential role in a reaction that is catalysed by an enzyme.
Co-factor – a substance which must be present in a sufficient quantity before certain enzymes can act.
Colic – severe abdominal pain, usually with fluctuating waves of pain.
Coma – a state of unconsciousness, which is unrousable.
Congestion – accumulation of fluid, such as blood or lymph.
Consumption – the old name for tuberculosis.
Contamination – pollution or infection.
Convulsion – a seizure due to an involuntary contraction of the muscles, which produces contortions of the body and limbs.
Copperas – any one of copper, iron or zinc sulphate, used as an adulterant in beer.
Coumarin – a substance produced by some plants or synthetically, used as an anti-coagulant.
Counter-irritant – a substance that causes irritation when applied to the skin and is used to relieve more deep-seated pain.
Cramp – a painful contraction of a muscle, which may be caused by a chemical imbalance of the salts in the tissues.
Crustacean – marine creature having a shell, e.g. shrimps, sea snails.
Cumulative – additional, increasing in quantity.
Cyanosis – a bluish discoloration of the tissues due to lack of oxygen.
Cystitis – inflammation of the bladder and urethra.
Cytochrome – a compound of a protein linked to haem; these are enzymes involved in electron transfer. See also Electron transfer chain.
Cytokines – proteins released by cells when activated by an antigen, acting as enhancing mediators for the immune response through interaction with specific cell surface receptors on leucocytes. There are several types: interkeukins, lymphokines, interferons and tumour necrosis factors.
Deficiency – lack of.
Defoliant – a chemical which, when applied to plants, causes their leaves to drop off.
Degeneration – deterioration and loss of specialised function of cells.
Delirium – an acute disorder of brain function due to toxicity, infection or a metabolic disorder or deficiency.
Dependence – physical and/or psychological effects produced by the habitual taking of certain drugs, with a compulsion to continue taking such drugs.
Depression – a reduction of normal activity; a psychiatric illness.
Diabetes – a metabolic disorder causing great thirst and much urine.
Dialysis – the separation of substances from a solution, as in the process of filtering waste from the blood of patients with kidney failure.
Diastolic – in measuring blood pressure, the lower number is the diastolic pressure, that is, the pressure between heartbeats when the heart muscle relaxes.
Dislocation – displacement from the normal position of a joint.
Distension – stretching and swelling.
Diuresis – increased secretion of urine by the kidneys.
Diuretic – a drug that promotes the excretion of salts and water by the kidneys.
DNA – deoxyribonucleic acid – the genetic material found in the nucleus of the cell, which controls heredity.
Dracontiasis – a tropical disease caused by the parasitic nematode Dracunculus medinensis, the guinea worm, which is transmitted to humans via contaminated drinking water.
Dyspepsia – indigestion.
Eczema – a common itchy skin disease treated with judicious use of corticosteroid creams and ointments, but mainly by the use of emollients.
Electron transfer chain – a method of converting chemical energy into a readily usable and storable form; the respiratory chain is the most important, as without oxygen we die.
Elevated – increased.
Emaciation – wasting of the body, due to malnutrition, cancer, tuberculosis or parasitic worms.
Emesis – vomiting.
Emollient – an agent that soothes and softens the skin.
Encephalitis – inflammation of the brain.
Encephalopathy – a disease affecting the functioning of the brain.
Endemic – frequently occurring in a particular region or population, usually of a disease.
Endotoxin – a poison contained by certain bacteria, released only when the bacterial cell is broken down or dies.
Enterotoxin – a poisonous substance acting on the gastrointestinal tract, causing vomiting, diarrhoea and abdominal pain.
Enzyme – a biological catalyst, that is, a protein, which in very small amounts speeds up the rate of a biological reaction, without being used up itself.
Eosinophilia – an increase in the number of white blood cells, called eosinophils, in the blood. Caused by certain drugs, allergies, parasitic infestations and some forms of leukaemia.
Epidemic – a sudden outbreak of infectious disease that spreads rapidly in a population.
Erythema multiforme – eruptions following a herpes simple infection; involves widespread flushing of the skin due to dilatation of the blood capillaries.
Erythropoietic – causing production of red blood cells in the bone marrow.
Eschar – a scab.
Excretion – removal of the waste products of metabolism from the body: carbon dioxide and water from the lungs, urine from the kidneys, faeces from the gastrointestinal tract and water and salts from sweat glands in the skin.
Exophthalmic – causing protrusion of the eyeball.
Exotoxin – a poison produced by a bacterial cell and secreted into the surrounding medium, as in botulism and tetanus.
Exudate – slow escape of liquid.
Factor – a substance that is essential to a physiological process.
Fats – the main form of stored energy in the body. It also acts as an insulation material and is one of the main constituents of our diet, which must contain an adequate supply of essential fatty acids.
Fatty acids – the basic constituents of many important lipids, including the triglycerides. Some fatty acids are essential, as we cannot synthesise them, and so they must be obtained from our diet.
Favism – an inherited enzyme deficiency causing red blood cells to become sensitive to a chemical in broad beans (fava beans). It destroys the red blood cells leading to severe haemolytic anaemia and requiring blood transfusion.
Ferritin – an iron-protein complex that is one of the body’s storage forms of iron.
Fibre – anatomically, a fibre is a threadlike structure such as a nerve, muscle or collagen fibre; dietetically, fibre is an important constituent of our diet, also called roughage, a non-digestable component needed for the proper functioning of the gastrointestinal tract.
Fibrosis – thickening and scarring of connective tissue, usually due to inflammation or injury.
Fluid ounce – see Ounce.
Fracture – break.
Free – not bound.
Fulminant – a condition or symptom, rapid, severe and of short duration.
Fungi – simple organisms, including yeasts, moulds and mushrooms.
Fungicide – an agent that kills fungi.
Gammaglobulin – consists mainly of immunoglobulins, a deficiency that results in an increased susceptibility to infections.
Gastric – pertaining to the stomach.
Gastrostomy – a surgical procedure in which an opening from the outside to the stomach is created, to facilitate feeding when swallowing food is impossible due to disease or to obstruction of the oesphagus.
Glycosuria – presence of glucose in the urine in abnormal amounts.
Goitre – a swelling of the neck resulting from enlargement of the thyroid gland.
Gout – an extremely painful condition, caused by uric acid crystals forming in the joints, particularly in the feet.
Grain – an old unit of mass, formerly used in medicine, equivalent to approximately 65mg. It was 1/7,000th part of a pound weight.
Granuloma – a localised collection of cells, usually produced in response to an infection or foreign body.
Griping – severe abdominal pains
Gynaecomastia – enlargement of the breasts in men, caused by some drugs as a side effect, but mainly caused by a hormonal imbalance or hormone therapy.
Haem – an iron-containing pigment (a porphyrin) that combines with the protein globin to form haemoglobin.
Haem- – relating to blood.
Haematemesis – vomiting blood.
Haemochromatosis – a hereditary disorder called iron storage disease or bronze diabetes, which causes damage and functional impairment to many organs.
Haemodialysis – blood flows on one side of a semi-permeable membrane, while dialysis fluid flows in the opposite direction on the other side of the membrane, removing accumulated waste products. In kidney failure, the patient’s blood supply must be connected to the machine for a number of hours, several times a week.
Haemoglobin – the oxygen-carrying substance in red blood cells.
Haemolysis/haemolytic – destruction of red blood cells or having that effect.
Haemoperfusion – a method of removing unwanted substances from the blood by passing it over a highly permeable synthetic membrane. In the treatment of poisoning, a material such as activated charcoal lies on the other side of the membrane to adsorb the unwanted substances, as the blood passes over the membrane.
Haemopoiesis – the process of producing blood cells and platelets.
Haemorrhage – bleeding, tends to be used to refer to severe blood loss.
Haemosiderin – a storage form of iron with a protein shell.
Hallucinogen – a substance which causes hallucinations.
Halogen – any of a specific group of elements, namely fluorine, chlorine, bromine, iodine or astatine.
Hayfever – allergic rhinitis – inflammation of nasal mucous membranes caused by allergy.
Hepatic – pertaining to the liver.
Hormesis – a controversial theory that states that low-dose stimulation by poisons can lead to high-dose inhibition of the effects of poisoning.
Host – a plant or animal upon which a parasite lives.
Hyper- – increased or excessive.
Hyperglycaemia – increased or high blood sugar level, as in diabetes.
Hyperlipidaemia – a high level of fats in the blood, e.g. cholesterol.
Hypertension – high blood pressure.
Hyperthermia – high body temperature.
Hypo- – lack, deficiency or decreased.
Hypogammaglobulinaemia – a deficiency of gammaglobulin in the blood. It can be inherited or acquired, as in lymphomas.
Hypoglycaemia – low blood sugar level.
Hypotension – low blood pressure.
Hypothermia – low body temperature.
Hypoxia – low oxygen level in the tissues.
Iatrogenic – an unforeseen or inevitable side effect, resulting from the treatment given for a condition.
Immunomodulatory – effect of modifying the immune response in order to treat or prevent a disease.
Incidence – frequency or range of occurrence.
Indicator – a substance that shows the presence of a chemical.
Inflammation – in response to injury, involves pain, heat, redness, swelling and loss of function.
Infusion – the slow injection of a substance usually into a vein, as with a saline drip.
Ingest – take in food.
Inhale – breathe in.
Inhibition – reduction or prevention of function.
Injection – administration by a syringe.
Insecticide – a poison specific to insects.
Insomnia – inability to sleep.
Interaction – effect produced by the mutual action of two or more substances.
Interleukin – one of a family of proteins that control some aspects of the immune response and haemopoiesis.
Intoxication – symptoms of poisoning due to ingestion of any toxic material, such as alcohol or heavy metals.
Intra- – within.
Intramuscular – into a muscle, a type of injection.
Intrathecal – a type of injection, directly into the cerebrospinal fluid contained in the meninges surrounding the spinal cord.
Intravascular – within a blood vessel.
Intravenous – a type of injection, directly into the bloodstream via a vein.
Involuntary muscle – not under conscious control, e.g. in gut, stomach, blood vessels.
Irreversible – cannot be reversed.
Irritability – typical response of certain tissues to a stimulus.
Irritant – causing irritation, e.g. nettles are an irritant and cause pain and swelling.
Isotonic – solutions which have the same osmotic pressure.
-itis – inflammation of an organ or tissue, e.g. arthritis.
In vitro fertilization – fertilization of an ovum outside the body, commonly referred to as a technique to produce a ‘test-tube’ baby.
Kidney – one of the pair of organs which excrete nitrogenous wastes, principally urea, from the blood. Only one working kidney is needed to survive.
Lachrymatory – causing the eyes to water.
Lactose – milk sugar.
Laryngeal – affecting the larynx.
Larvae – the pre-adult stage of life in some insects and nematodes. Caterpillars are the larvae of butterflies.
Larvicide – a poison specific to the larval stage of insect life.
Latency – period of delay in development.
Lavage – washing out part of the body with water or a medicated solution.
Lesion – area of damaged tissue, caused by disease or wounding.
Leukaemia – one of various malignant diseases in which there is increased production of some white blood cells, the leucocytes, as well as suppression of the other white cells, the red cells and platelets in the blood.
Lipoprotein – a type of protein, found in the blood and lymph, which is combined with fats and other lipids.
Luminescent – glows in the dark.
Lymphoma – a malignant tumour of the lymph glands.
-lysis – breakdown or remission.
Malignant – life-threatening if untreated, e.g. cancer.
Malleability – capable of being beaten or rolled into shape.
Mammary – pertaining to the breast.
ME – myalgic encephalopathy – chronic fatigue syndrome.
Medulla – the inner region of any tissue or organ, also the name of the part at the base of the brain.
Medullary paralysis – stopping of major pathways for nerve impulses, and centres for circulation, salivation, swallowing and respiration.
Metabolism – the chemical and physical processes in the body which maintain growth and functioning.
Methaemoglobinaemia – a substance formed when the iron present in haemoglobin is oxidised from the ferrous to the ferric form. It cannot bind with or transport oxygen to the tissues. It can be produced by some drugs or may be an inherited condition.
Microgram – a millionth part of a gram.
Milligram – a thousandth part of a gram.
Minerals – naturally occurring, inorganic substances essential for life.
Miscarriage – the loss of the foetus during pregnancy; an abortion.
Mitochondria – structures in the cytoplasm of every cell; they are the site of energy production within the cell.
Molecule – the smallest particle of a substance; it is composed of a group of atoms.
Morels and false morels – mushrooms and toadstools.
Motility – the ability to move.
MRSA – methicillin (or multiple) resistant staphylococcus aureus, a very severe infection.
Mucosa – moist membrane linings of many body cavities and tubular structures, including the nasal passages, respiratory tract, the mouth and the gastro-intestinal tract.
Muscle – a tissue that can contract and relax, so producing movement.
Myalgia – painful muscles.
Myo- – pertaining to the muscles.
Myoglobin – an iron-containing protein, similar to haemoglobin, which is found in muscle cells. It can bind to oxygen and so acts as an oxygen reservoir within the muscle cells.
Narcosis – a state of reduced consciousness or total unconsciousness caused by the use of narcotic drugs, such as opium.
Necro – death of.
Necrosis – the death of some or all the cells of an organ or tissue.
Nematode – a roundworm; there are many types, such as hookworm, guinea worm and threadworm, which are parasitic in plants, animals and humans.
Nephro- – relating to the kidneys.
Nervous system – a network of specialised cells throughout the body, which pass information around the body. The brain and spinal cord form the central nervous system, and everything else is the peripheral nervous system, which includes the autonomic nervous system and comprises the sympathetic and the parasympathetic nervous systems.
Neuritis – inflammation of one or more nerves.
Neuro- – pertaining to the nervous system.
Neuropathy – a disease of the peripheral nerves.
Nostrum – a traditional remedy of the pharmacist’s own compounding.
NSAIDs – non-steroidal anti-inflammatory drugs, e.g. ibuprofen.
Oedema – swelling caused by the accumulation of fluid in the tissues.
Onchocerciasis – a tropical disease of the skin and underlying tissues, caused by a parasitic worm. It leads to the growth of fibrous nodular tumours around the worms; later bacterial infections can lead to abscesses. Infestation can also lead to blindness.
Opiate / opioid – acting like opium, can be natural or synthetic.
Optical – relating to sight and the eye.
Osmosis – the passage of a fluid from a less concentrated to a more concentrated solution through a semi-permeable membrane.
Osmotic pressure – the pressure exerted during osmosis; the more concentrated the solution the higher the osmotic pressure.
Osteoporosis – a condition in which there is loss of bony tissue causing brittle bones which are liable to fracture.
Ounce – equal to 480 grains and a twelfth part of a pound troy, or one sixteenth part of a pound avoirdupois. A fluid ounce was the volume of distilled water which weighed an ounce. There are 20 fluid ounces to a pint in the UK, but only 16 to the US pint.
Oxidation – the process of oxidising, reacting with oxygen.Oxyhaemoglobin – haemoglobin with oxygen bound to it.
Paralyticileus – functional obstruction of the ileus (small intestine) due to loss of peristatic movement.
Paraesthesia – abnormal sensation, such as pins and needles.
Parasympathetic nervous system – enervates the blood vessels and most internal organs. This system works in balance with the sympathetic nervous system, frequently opposing its actions.
Parenteral – administered by a route other than by mouth, e.g. by injection.
Path- – a prefix denoting disease.
-pathy – a suffix denoting disease.
Peptide – a molecule formed by the bonding together of two or more amino acids.
Peri- – about, near or enclosing.
Pericarditis – inflammation of the membranous sac (pericardium) around the heart.
Peripheral – not central. See Nervous system.
Peritoneal dialysis – a method of dialysis that uses the peritoneum (membrane of the abdominal cavity) as a semi-permeable membrane. Used when haemodialysis is not appropriate.
Pesticide – a poison specific to pests.
Petechiae – small, round, flat dark-red spots caused by bleeding into the skin or beneath the mucous membrane.
Phenol – also known as carbolic acid, a strong disinfectant, no longer in use.
Phenylketonuria – an inherited defect of protein metabolism.
Photophobia – an abnormal reaction to light, where such exposure causes intense discomfort of the eyes. It may be associated with dilatation of the pupils as a result of eye drops, or with migraine, or infections e.g. measles, German measles, meningitis.
Photosensitivity – an abnormal reaction of the skin to sunlight.
Placenta – an organ that develops within the uterus to supply the foetus with food and oxygen and eliminate waste during pregnancy.
Placebo – a medicine that is ineffective but may help to relieve a condition because the patient has faith in its powers. New drugs are always tested against placebos in clinical trials.
Pleura – covering of the lungs and inner surface of the chest wall.
Pleuro – a prefix denoting the pleura or the side of the body.
Plumbism – lead poisoning.
Poly – many.
Polypharmacy – many medicines all being prescribed and taken by a single patient – a prime source of problems.
Porphyria – a group of rare inherited disorders resulting from errors of metabolism caused by enzyme deficiencies in the production of haem.
Porphyrins – pigments derived from porphin, which form chelates with metals, such as iron, copper, cobalt and zinc. These chelates are constituents of important body chemicals such as haemoglobin, myoglobin and the cytochromes.
Potentiation – to make more effective or more potent.
Precursor – existing before, and being converted to the active form.
Prophylaxis – a means of preventing disease, e.g. immunisation.
Proteins – nitrogen containing organic compounds made up of one or more chains of amino acids, which are synthesised in the body. They are essential constituents of the body, forming structural tissues, like muscles, as well as enzymes and hormones.
Psychosis – a mental disorder in which there is loss of contact with reality, e.g. schizophrenia.
Pulmonary – pertaining to the lungs.
Pungent – strong smelling or tasting.
Purgative – a drug that stimulates or increases the frequency of bowel evacuation.
Pyrexia – high temperature, fever.
Quack medicine – claims to cure everything but contains nothing of medicinal value.
QT interval – the interval shown on an electrocardiogram (ECG) that contains the deflections produced by contraction of the heart’s ventricles.
Quickening – the first movement of the foetus felt by the mother, usually at about 16 weeks of pregnancy.
Raynaud’s disease – a condition of unknown cause in which the arteries of the fingers are unduly reactive and enter spasm involuntarily when the hands are cold. A similar condition results from use of vibratory tools and the ingestion of ergot derivatives and may result in gangrene.
Receptor – a specialised group of cells, which can detect changes in the environment and trigger nervous impulses in the sensory nervous system.
Renal – pertaining to the kidney.
Reversible – able to be reversed or changed.
Rhabdomyolysis – a condition resulting in breakdown of the muscle fibres and progressive weakness.
Rhinitis – inflammation of the nasal mucous membranes, e.g. caused by a virus or allergy.
Ringworm – a fungal infection of the skin, scalp and nails.
RNA – ribonucleic acid – found in the nucleus and cytoplasm of cells; it is involved in the synthesis of proteins.
Scabies – a skin infection caused by a mite that tunnels into the skin to lay eggs; causes severe itching, particularly at night.
Schistosomiasis – an illness caused by a parasitic blood fluke. The larval stage is transmitted by water-snails, in water contaminated with sewage, in the Americas, Africa and Asia. Also called bilharziasis.
Septicaemia – blood poisoning that can result in widespread destruction of the tissues following the absorption of infective organisms or toxins from the bloodstream.
Shock – condition associated with circulatory collapse, when the arterial blood pressure is too low to maintain an adequate blood supply to the tissues.
Sign – an indication of illness observed by a doctor, but that is not apparent to the patient. See also Symptom.
Smooth muscle – also called involuntary muscle; produces slow, long-term contractions of which we are not consciously aware, as in the stomach and intestines, blood vessels and the bladder.
Spasm – a sustained muscular contraction which is involuntary.
-static – stopped.
Status epilepticus – a medical emergency in which there are repeated epileptic convulsions without return of consciousness between them.
Sterilisation – destruction of micro-organisms by heat, radiation, chemicals or filtration.
Stevens-Johnson syndrome – a rare skin condition characterised by severe blisters and bleeding in the mucous membranes of the eyes, lips, mouth, nasal passages and genitals. This syndrome is believed to be a life-threatening form of erythema multiforme and in many cases is thought to be caused by a drug reaction.
Stomatitis – inflammation of the mucous lining of the mouth.
Stricture – narrowing of any tubular part of the body, e.g. oesophagus.
Stridor – the noise of breathing, which is louder and harsher than a wheeze, heard when the trachea or larynx is obstructed.
Surfactant – a wetting agent, e.g. detergent.
Sympathetic nervous system – enervates the blood vessels, heart, lungs, intestines and other abdominal organs, also the sweat glands, salivary glands and genitals. This system works in balance with the parasympathetic nervous system, frequently opposing its actions.
Symptoms – an indicator of illness noticed by the patient. See Sign.
Syndrome – a collection of signs and symptoms indicative of a specific disorder.
Synergist – a substance (e.g. a drug) that interacts with another substance to produce an increased effect, which is greater than would be achieved by the sum of the effects of each substance if given separately.
Synergy – increased effect, greater than the sum of each part separately.
Synthetic – man-made.
Syphilis – a sexually transmitted disease caused by a bacterium.
Systolic – the highest pressure when the ventricles of the heart are contracting during a heart beat. See Blood pressure and Diastolic.
Tachycardia – an increased heart rate, above normal.
Teratogen – an agent that damages the embryo or foetus by causing developmental abnormalities, in utero.
Tetany – muscular spasm and twitching, due to low blood calcium level, particularly of the face, hands and feet.
Thiol group – a sulphur atom combined with a hydrogen atom (-SH).
Thrombosis – a blood clot with a vein.
Thyrotoxicosis – a syndrome caused by excess thyroid hormone.
Total parenteral nutrition – a form of artificial feeding in which all nutrients, carbohydrates, proteins, fats, vitamins and minerals are administered by way of a tube, either intravenously or by using a naso-gastric tube.
-toxic – poisonous.
Toxin – a poison produced by a living organism, e.g. a bacterium.
Toxicity – the state or degree of poisoning.
Trace element (or micronutrient) – a substance needed in a very small amount for normal healthy growth; often components or activators of enzymes.
Tracheostomy – an operation in which a hole is made into the trachea through the neck to relieve an obstruction to breathing.
Trimer – a substance formed from three molecules of a monomer.
Tumour – an abnormal swelling or growth, which may be benign or malignant.
Turpentine – an essential oil, extracted from long-leaf pine oil, by steam distillation. Turpentine susbtitute is a petroleum fraction of similar boiling point.
-uria – pertaining to urine or to urination.
Urine – fluid excreted by the kidneys, contains many of the body’s waste products.
Vasculo- – pertaining to blood vessels.
Vaso- – pertaining to blood vessels.
Vasoconstriction – decrease in the diameter of blood vessels, especially arteries.
Vasodilatation – increase in the diameter of blood vessels, especially arteries.
Vasospasm – sustained involuntary muscular contraction of the blood vessels, such as in the hands in Raynaud’s disease.
Vector – anything that transmits disease.
Vertigo – a disabling sensation of spinning or tilting that is a symptom of disease in the inner ear or of the vestibular nerve.
Vitamins – essential food factors, required in small amounts for healthy growth and development. They cannot be synthesised by the body and are thus essential constituents of our diet.
Voluntary muscle – under conscious control, e.g. skeletal muscles involved in movement.