Glossary

If you did not find the word you were looking for try these glossaries:

 

A

  • Abducens nerve

    Cranial nerve VI - innervates the lateral rectus muscle of the eye. It is the only cranial nerve that originates from the dorsal surface of the brainstem.

  • Ablation

    Removal or destruction of tissue.

  • Acetylcholine (ACh)

    A neurotransmitter found in the brain, spinal cord, neuromuscular junction and autonomic nervous system.

  • Acetylcholinesterase (AChE)

    Enzyme that terminates the action of acetylcholine.

  • Action potential

    Electrical 'all-or-none' impulse that transmits information within the nervous system.

  • Adrenergic

    Associated with catecholamines.

  • Afferent

    Neural information flowing from the periphery to more central areas of the nervous system.

  • Agonist

    Chemical that acts like a neurotransmitter; increases the effect of a neurotransmitter.

  • Alzheimer's disease

    A degenerative brain disease. Characterised by memory loss and disorientation.

  • Amnesia

    Partial or complete loss of memory. 'Anterograde' amnesia is when people cannot form new memories.

  • Amphetamine

    A synthetic central nervous system stimulant.

  • Amplitude

    The size or magnitude of a signal or response.

  • Amygdala

    Brain structure that is part of the limbic system. Implicated in emotion.

  • Analgesia

    Insensitivity to pain.

  • Antagonist

    Chemical that blocks the action of a neurotransmitter

  • Anterior

    A directional term meaning toward the front.

  • Anterior commissure

    A small fibre tract that connects the right and left cerebral hemispheres (like the corpus callosum).

  • Aphasia

    Inability to speak or understand language.

  • Aqueous humor

    Fluid in the space between the cornea and lens of the eye.

  • Arachnoid

    Middle layer of the meninges.

  • Astrocyte (astroglia)

    A glial cell that supports neurons.

  • Autoradiography

    Neuroanatomical method using radioactivity that is incorporated into neurons.

  • Axodendritic (synapse)

    A synapse formed by contact between a presynaptic axon and a postsynaptic dendrite.

  • Axon

    The part of the neuron that takes information AWAY from the cell body.

B

  • Basal Ganglia

    Areas of the brain that are important for movement. These areas include the putamen, caudate nucleus, globus pallidus, subthalamic nucleus and substantia nigra.

  • Bipolar neuron

    Neuron with only two processes extending from the cell body.

  • Blood brain barrier

    A system of astrocytes and capillaries in the brain that prevents the passage of specific substances.

  • Brainstem

    The central core of the brain.

C

  • Cauda equina

    The 'horse's tail' made up of a bundle of spinal nerves at the base of the spinal cord.

  • Caudal

    A directional term meaning toward the tail end.

  • Cell body

    Also called the soma; the part of the cell that contains the nucleus.

  • Central Nervous System (CNS)

    The brain and spinal cord.

  • Central sulcus

    Large groove in the brain that separates the frontal and parietal lobes.

  • Cerebellum

    Area of the brain above the pons and medulla that is important for balance and posture.

  • Cerebral aqueduct

    Part of the ventricular system that connects the third and fourth ventricles.

  • Cerebral cortex

    Outermost layer (the gray matter) of the cerebral hemisphere.

  • Cerebrospinal fluid (CSF)

    Clear fluid in the ventricular system.

  • Chimeric figure

    Figure using two separate faces on each half. These figures are used in split brain experiments.

  • Choroid plexus

    Vascular structures in the ventricular system that produce cerebrospinal fluid.

  • Cingulate cortex

    Part of the limbic system. Located directly above the corpus callosum. Important for emotional behavior.

  • Circadian

    About one day; used to describe some body rhythms.

  • Cochlea

    Inner ear structure important for hearing.

  • Cone

    Receptor found in the retina important for colour vision and detailed sight.

  • Cornea

    Transparent front coat of the eye.

  • Corpus callosum

    Large collection of axons that connect the left and right hemispheres of the brain.

  • Cranial nerves

    12 pairs of nerves that exit from the brain.

  • Cranium

    The part of the skull that contains the brain.

D

  • Dendrite

    Extensions from the neuron cell body that take information TO the cell body.

  • Depolarisation

    Movement of the membrane potential toward 0 mV; a decrease in polarisation.

  • Dopamine

    A neurotransmitter found in many areas of the brain. Important for movement and other behaviour.

  • Dorsal root

    Bundle of nerve fibres taking information into the spinal cord.

  • Dura

    Outermost layer of the meninges.

E

  • Electroencephalogram (EEG)

    Record of electrical activity of the brain obtained from scalp electrodes.

  • Endorphin

    Neurotransmitter with similar properties as opiates. Important for pain reduction.

  • Excitatory Postsynaptic Potential (EPSP)

    A graded depolarisation of the postsynaptic cell.

F

  • Fetal Alcohol Syndrome

    When a foetus is exposed to alcohol and consequently develops a pattern of unusual facial features and impaired brain development

  • Fornix

    Pathway that connects the hippocampus with the mamillary bodies.

  • Fovea

    Central part of retina; area of retina with most accurate vision.

G

  • Glia

    Non-neural support cells of the nervous system.

  • Gyrus (plural is gyri)

    'Hills' or 'bumps' on the brain that are separated by fissures.

H

  • Hippocampus

    Area of the limbic system important for memory.

  • Hormones

    Chemicals used by endocrine system to transmit messages.

  • Hypothalamus

    Brain structure that monitors internal environment and attempts to maintain balance of these systems. Controls the pituitary.

I

  • Inferior colliculus

    Midbrain structure important for hearing.

  • Iris

    Muscles of eye that control the size of the pupil. Gives color to the eye.

L

  • Lens

    Transparent structure in the eye that focuses light on the retina.

  • Lesion

    Injury caused by destruction of tissue.

  • Limbic system (or Limbic areas)

    Interconnected areas of the brain important for emotional and other behaviours.

M

  • Medulla

    Part of the brain stem important for breathing, respiration and other behaviours.

  • Meninges

    Series of three membranes (dura mater, arachnoid, pia mater) that cover the brain and spinal cord.

  • Myelin sheath

    Fatty substance that surrounds some axons.

N

  • Neurotransmitters

    Chemicals that transmit information across the synapse to communicate from one neuron to another.

  • Node of Ranvier

    Short unmyelinated segment of an axon.

O

  • Occipital lobe

    Area of the brain located behind the parietal lobe and temporal lobe and responsible for vision.

  • Optic chiasm

    Crossing of the fibers from each retina.

  • Ossicles

    Bones in the middle ear.

P

  • Parkinson's disease

    Neurological disorder caused by damage to the dopamine system of the brain; symptoms include tremor, rigidity, slow movement.

  • Pia

    Inner most layer of the meninges. Adjacent to the surface of the brain.

  • Pituitary

    'Master' gland attached to the base of the brain that secretes hormones.

  • Pons

    Area of the brainstem between the medulla and the midbrain.

  • Proprioceptor

    Sensory receptor providing information related to body position, mainly in muscles and tendons.

R

  • Retina

    Innermost layer of the eye; contains receptors responsive to light.

  • Rod

    Receptor found in the retina important for in low light conditions.

S

  • Soma

    The neuron cell body. Contains the nucleus.

  • Sulcus (plural is sulci)

    Groove located on the surface of the brain.

  • Synapse

    Functional connection between a terminal of one neuron with a membrane of another neuron.

T

  • Tectum

    "Roof" of the midbrain.

  • Tegmentum

    "Floor" of the midbrain.

  • Thalamus

    Group of nuclei in the diencephalon of the brain. The different nuclei have sensory and motor functions.

V

  • Ventricles

    Hollow spaces within the brain that are filled with cerebrospinal fluid.