Action potential: the way in which a neuron becomes active, creating an electrical signal that then passes down the neuron.
Adrenaline: also known as epinephrine, adrenaline is a hormone released by the adrenal glands and is very important in the fight-or-flight response of the sympathetic nervous system.
Amygdala: an almond shaped brain structure, one on each side. It is very important in how we produce and perceive emotions.
Aneurysm: a bulb in a blood vessel which causes turbulent flow of the blood. They happen most commonly in the brain and in the abdomen.
Antibodies: immune markers that we raise having been exposed to a bacteria or virus. It means we can combat them quickly next time and so are immune to their charms.
Autonomic: involuntary and unconscious
Autonomic nervous system: All of the bodily functions over which we have no conscious awareness are controlled by the autonomic nervous system. The cardiovascular system, the endocrine system, the digestive system and lots of others come under its control.
Axon: the part of the neuron that protrudes from the cell body and takes the signal to the next neuron or a muscle.
Axon hillock: the area of the axon that decides whether there has been enough net excitation (over inhibition) caused in its neuron by all of the other neurons synapsing onto it.
Bioabsorbable: a substance that the body can absorb to become part of its tissue.
Bronchospasm: narrowing of the airways in the lungs.
Cerebrovascular system: the blood vessels that bring blood to and away from the brain.
Cilia: tiny little hairs that are present on the surface of some cells in the body.
Ciliated pseudostratified columnar epithelial cells: cells that are found lining the sinuses. They look like layers under the microscope but there is actually only one layer, they are just different sizes. They have cilia on their outer surface to move the mucus along.
Cocci: any bacteria that has a sphere-like shape will have a name ending in –coccus (singular) or cocci (plural).
Coccobacilli: any bacteria that has a shape in between the spherical cocci and the rod-like bacilli.
Concentration gradient: as you pour cordial into a glass of water, it will be more concentrated at the bottom initially. Over time it will spread to be equally distributed in the glass. The concentration gradient is driving this movement from areas of high concentration to areas of low. It is the same principle by which people distribute themselves in lecture theatres, and bathrooms.
Cortical spreading depolarisation: a wave of excitation, or depolarisation, passes over the cortex of the brain in migraine.
Cortical spreading depression: The wave of excitation (cortical spreading depolarisation) seen in migraine is followed by cortical spreading depression, or a wave of relative inactivity (depression).
Cortisol: a hormone released from the adrenal gland which regulates our metabolism and immune response and is heavily involved in our response to stress (physical and mental).
Depolarisation: the insides of our neurons are more negative with respect to the outside. The inside and outside are polar opposites, or polarised. Depolarisation is when the inside of the cells gets more positive (so that the two sides are less polarised).
Diuretics: any chemical agent that makes us urinate more. Coffee and alcohol are the most common.
Dyspnoea: shortness of breath
Endocrine system: the system that regulates the body’s activity via hormones.
Endogenous opioids: our own natural painkillers, they act in the pain centres of the brain to dampen our perception of pain.
Endorphins: these endogenous opioids are released to relieve stress and pain in the body.
Endoscopic: the use of a tiny camera on the end of a very thin tube so that structures can be seen inside our body.
Enzyme: any substance that speeds up a chemical reaction.
Epigenetics: the study of how our environment can change how our genes are switched on and off (and therefore what proteins are produced, or not as the case may be).
Episodic cluster pain: if you have a break of from one month up to several years between a cluster headache attack, this will be diagnosed as episodic.
Epithelial cells: surface cells that separate the outside from the inside. They are found in skin, blood vessels, the urinary tract, the respiratory system, the urinary system and organs.
Gamma amino butyric acid (GABA): the brain’s main inhibitory neurotransmitter.
Ganglion: a grouping of neurons, and their cell bodies.
Genome-wide association studies (GWAS): an observational study in which the whole genome is investigated or variants between individuals to see if any of these variants can be associated with a trait or disorder.
Glial cells: support cells in the nervous system. They wrap around neurons to make signals go faster (the myelin sheath) and they mop up toxins and other substances that may harm the neuron or its action.
Glutamate: the most common excitatory neurotransmitter in the brain.
Goblet cells: a kind of epithelium cell that releases mucus.
Histamine: the first responders to tissue injury, histamine drives inflammation and also acts in the brain to keep us alert.
Hypothalamus: the endocrine system’s puppet master, the hypothalamus is a structure under the cerebral cortex that reacts to the concentration of circulating hormones to either make sure more are produced and released or that production is stopped.
Hypovolemia: too little volume, usually associated with blood volume.
Immunoglobulins: antibodies produced by white blood cells that recognise and stick to antigens such as bacteria or viruses, but also allergens so that they can be destroyed effectively.
Inhibitory neurons: neurons that release inhibitory neurotransmitter meaning that activity of the neurons they connect with will be suppressed.
Ion: a charged particle, either positive or negative.
Ischemia: a lack of blood flow due to a restriction of blood supply (usually a blockage of some sort).
Limbic system: the emotional system of the brain, the limbic system comprises a number of loosely connected areas that allow us to recognise and produce appropriate emotions in the setting in which we find ourselves.
Lysozymes: organelles inside each cell body that contain enzymes that will kill the cell if the lysosome bursts (if the cell isn’t functioning correctly, for example.)
Magnetoencephalography: a neuroscientific technique that allows us to map what is happening in the brain in addition to where and when. It works by detecting the magnetic fields that the electrical activity in the brain result in.
Mast cells: these cells live just under the epithelium and release their contents, including histamine and other factors that trigger the immune system when the tissue comes under attack.
Meninges: the covering of the brain between the grey matter of the cerebral cortex and the skull.
Myelin sheath: the coating that glial cells provide by wrapping themselves around the axon to allow it to pass the electrical signal (action potential) down its length quicker.
Neurochemicals: any chemicals that interact with neurons. These may be neurotransmitters but also chemicals that control how well neurotransmitters work.
Neurons: nerve cells. There are many forms but the main two are motor (taking information from the brain to the body) and sensory (taking information from the body to the brain). The brain is also full of interneurons allowing different areas of the brain to talk to each other.
Neuropeptide: small protein-like molecules that influence how neurons and other cells in the body work.
Neutrophils: white blood cells that are important in our response to damage, infection or other stressors.
Nociceptors: pain receptors that are sensory neurons that detect potentially damaging stimuli. It is only perceived as pain though once this signal has been processed in the brain.
Nucleus: the brain of the cell, this is the organelle in the cell body where all of our chromosomes live.
Oxytocin: made in the hypothalamus, this is the bonding hormone. It is released after childbirth and at the dawn of new relationships.
Pain gating: a way of lessening the impact of pain signals by reducing our ability to perceive them. Examples include rubbing it better (the brain will listen to the mechanical signal over the pain signal) or distraction.
Pain receptors: or nociceptors; sensory neurons that detect potentially damaging stimuli.
Parasympathetic system: the rest and digest part of the autonomic nervous system that calms the body down after a period of stress. Also active when the body is maintaining calm.
Patent foramen ovale: a hole in the septum (the barrier between the right and left of the heart) of the atrium which has not closed up properly after birth.
Periodic cluster pain: when cluster headaches occur at the same time of year.
Phosphenes: spots of light that can be detected by stimulating either the brain or the retina directly (by pressing your finger to your closed eyelid).
Photic sneeze: sneezing caused by exposure to bright light caused by cross wiring in your brain.
Piloerection: when the hairs on your arm stand on end.
Pituitary gland: the puppet of the hypothalamus, this master gland sits just below the hypothalamus and sends signals to the other glands of the body to produce or release their hormones. It also directly releases oxytocin and anti-diuretic hormone, which acts on the kidneys. Both are made in the hypothalamus.
Population genetics: the study of genetic variation within a population allowing us to see how this changes over time.
Post-nasal drip: when mucus runs down the back of your nose into your throat.
Postsynaptic membrane: The membrane of a dendrite or cell body that comes after the synapse. This is where the neurotransmitter that has been dumped into the gap (synapse) by the previous neurons binds with proteins to open ion channels starting off the electrical activity again.
Preoptic nucleus: an area of the hypothalamus very important in temperature regulation and sexual activity.
Primary motor cortex: the area of the brain just in front of the central sulcus in the frontal cortex that controls all of the fine movements our body has to do.
Primary viral infection: a virus that was able to attack and compromise our body in its fit state.
Primary visual cortex: the first area of the visual system where light is processed into lines. It is located at the very back of the brain in the occipital cortex.
Proprioception: the sense by which we know what the muscles and joints of our body are doing.
Prostaglandins: little lipid molecules that are important in the inflammatory response to tissue damage.
Referred pain: pain that you feel as coming from one place when actually it originates in another. It is caused by the pain signals from the two places being lumped together and our brain is not able to discriminate between the two (e.g. pain signals from the heart are perceived as pain in the left arm).
Rhinitis: inflammation inside the nose.
Rhinovirus: infections that cause the common cold.
Scotoma: a small, usually circular, blind spot in the visual field (the space we can see).
Serotonin: a neurotransmitter important in emotional regulation; also known as the happy hormone.
Serotonin agonist: an agonist is any molecule that acts just like or causes the same effect as a neurotransmitter, in this case serotonin.
Sinus: the sinuses are small, hollow spaces behind the cheekbones and forehead that connect to the nose. The term sinus is also interchangeable with sinusitis.
Sinusitis: inflammation of the lining of the sinuses.
Somatosensation: our ability to feel mechanical and temperature stimuli on the surface of the body.
Somatosensory cortex: an area of the brain just behind the central sulcus in the parietal lobe where all the sensory information coming from the body is processed so that we know what we are feeling and where.
Sub-mucosa: the layer of tissue beneath the mucous membrane. Here, we find blood vessels and nerves among other things.
Suprachiasmatic nucleus: an area of the hypothalamus that responds to light input to create our daily circadian rhythm.
Sympathetic system: the fight or flight part of the autonomic nervous system, it marshals our resources to allow us to deal effectively with threat or stress.
Synaptic clefts: the gap between neurons that are communicating with each other. It is where the neurotransmitters are released into and so houses the chemical part of electrochemical conduction.
Terminal bouton: the last part of the neuron. Arrival of an action potential here causes an influx of calcium into the bouton, which triggers the vesicles to fuse with the terminal membrane to dump their contents out into the synaptic cleft.
Thalamocortical loops: reciprocal loops of connected neurons and areas that function together to bring about a behaviour such as movement, vision, thinking, etc. The thalamus acts as the pacemaker.
Thalamus: the grand relay centre of the brain, all sensory and motor signals pass through here on their way to the cortex and often back again as part of thalamocortical loops.
Trigeminal nerve: responsible for sensation in the face and also movements such as biting and chewing.
Trigeminal pathway: this pathway carries pain, touch and temperature information to the brain from the face.
Vascular system: any system that involves blood vessels – for example cardiovascular system in the heart or cerebrovascular system in the brain.
Vasoactive: any chemical or agent that can interact and change the diameter or action of blood vessels.
Vasoconstrictor: any chemical or agent that can narrow the diameter of blood vessels.
Vasodilation: any chemical or agent that can widen the diameter of blood vessels.
Vesicles: tiny pouches that contain a substance (such as neurotransmitter vesicles).
Zona incerta: an area beneath the cortex of the brain that is involved in the perception of the affective component of pain (i.e. how bad the pain is) as opposed to the sensory component of pain (what it feels like). Activity here is coincident with chronic pain in the absence of a sensory stimulus.