Neuroanatomy An Illustrated Colour Text, 4 ed.


Acalculia – Inability to calculate

Accommodation – Act of refocusing the visual image

Acromegaly – Overgrowth of the skeleton and organs caused by excessive release of growth hormone from a pituitary tumour

Acuity – Resolving power

Action potential – Transient reversal of the resting potential that is propagated along the axon

Adenoma – Benign tumour

Adhesion – Scarring of tissues, fixing them together

Adipsia – Inability, or loss of desire, to drink

Aetiology – Relating to the cause of disease

Afferent – Carrying towards (e.g. cerebellar afferent neurones carry impulses to the cerebellum)

Agnosia – Inability to recognise objects

Agraphia – Inability to write

Akinesia – Loss, or slowness, of movement

Alexia – Inability to read

Amnesia – Loss of memory

Anastomosis – Intercommunication between vessels (e.g. circulus arteriosus or circle of Willis)

Aneurysm – Abnormal dilatation of an artery

Angioma – Congenital swollen collection of blood vessels

Angiography – Demonstration of the arterial system after injection of an opaque medium

Anomia – Inability to name objects

Antidiuretic – An agent that reduces the volume of urine produced by the kidney

Aphagia – Inability, or loss of desire, to eat

Aphasia – Loss of ability to use language

Apraxia – Loss of skilled movements despite preservation of power, sensation and coordination

Arachnoid mater – Middle of the three meningeal layers enveloping the central nervous system

Areflexia – Loss of reflexes

Arthritis – Inflammation of one or more joints

Astrocyte (astroglial cell) – A type of neuroglial cell (q.v.) that may form the blood–brain-barrier

Ataxia – Loss of ability to coordinate voluntary movements

Atrophy – Wasting or degeneration

Axon – The nerve fibre carrying impulses away from the cell body

Baroreceptor – Neuronal sensory ending that detects changes in arterial blood pressure

Biopsy – Tissue sample taken from a patient for the diagnosis of disease

Bloodbrain barrier – A selectively permeable barrier between the circulating blood and the brain believed to be formed by astrocytes

Bulimia – Overeating disorder

Bradykinesia – Slowness of movement

Brain stem – The stalk-like portion of the brain connecting the cerebral hemispheres with the spinal cord

Bulbar palsy – Weakness of tongue, pharynx and larynx resulting from disease of the lower cranial nerves

Cataract – Opacity of the lens of the eye, leading to deterioration of vision

Cell body – The part of the neurone that contains the nucleus and possesses dendritic and axonal processes

Central nervous system – The brain and spinal cord

Cephalic – Relating to the head

Cerebrum – The largest, most highly developed part of the brain comprising two cerebral hemispheres

Cerebrospinal fluid (CSF) – The clear watery fluid that surrounds the brain and spinal cord

Chemoreceptor – Neuronal sensory ending that detects changes in the chemical composition of circulating blood

Chiasma – Decussation or crossing over of nerve fibres (e.g. optic chiasma)

Chorea – Involuntary, abnormal movements of the face and limbs

Collateral – A side-branch of a nerve or blood vessel

Coma – Prolonged and unnatural state of unconsciousness

Computed tomography (CT) – Imaging technique utilising X-rays to visualise the structure of the nervous system

Concussion – Loss of consciousness caused by head injury

Contralateral – Relating to the opposite side

Contusion – Bruising

Convulsion – Involuntary contraction or spasm of muscles

Cordotomy – Neurosurgical procedure to destroy specific pathways in the spinal cord

Craniopharyngioma – Congenital tumour of the base of the brain

Craniotomy – Neurosurgical procedure to open the cranial cavity

Cushing’s disease – Overgrowth of the adrenal glands causing excessive release of corticosteroid hormones

Decussation – Crossing over of nerve fibres from one side of the CNS to the other (e.g. pyramidal decussation)

Dementia – Loss of mental abilities

Demyelination – Loss of the myelin sheath surrounding neuronal axons

Dendrite – Branching process of a neurone that receives information from other neurones and conducts electrical changes to the cell body

Diabetes insipidus – Failure of the posterior pituitary gland causing reduced release of antidiuretic hormone

Diabetes mellitus – A disorder of carbohydrate metabolism caused by lack of insulin

Dorsal root ganglion – Location of cell bodies of primary afferent neurones entering the spinal cord through the dorsal roots of spinal nerves

Dura mater – Outermost of the three meningeal layers that envelop the central nervous system

Dysarthria – Inability to pronounce

Dysphagia – Inability to swallow

Dysphonia – Inability to produce the voice

Echocardiography – The use of ultrasound to display the action of the heart

Efferent – Carrying away from (e.g. striatal efferent fibres carry impulses away from the striatum)

Electroencephalography (EEG) – Technique to detect the surface electrical activity of the brain

Electromyography – Technique to determine the electrical activity of muscles

Emetic – Causing nausea and vomiting

Encephalopathy – Disorder of the brain

Entrapment neuropathy – Nerve injury caused by compression of a nerve within a tunnel or at a change in direction

Ependymal cells (ependyma) – Epithelial cells lining the ventricular system

Epilepsy – Paroxysmal attack of disturbed consciousness and sensorimotor function resulting from abnormal electrophysiological discharges of the brain

Fasciculation – Spontaneous contraction of denervated motor units, visible on inspection

Fasciculus – Bundle of nerve fibres (e.g. medial longitudinal fasciculus)

Febrile – Refers to raised body temperature (fever)

Fibrillation – Spontaneous contraction of denervated muscle fibres, detected on electromyography

Foramen – An opening (e.g. foramen magnum)

Ganglion – A collection of nerve cell bodies outside the CNS (e.g. dorsal root ganglion)

General paralysis of the insane (GPI) – Disease of the frontal lobes caused by late neurosyphilis

Glia – see Neuroglia

Glioma – Tumour derived from glial cells

Haematoma – Blood clot

Haemorrhage – Escape of blood from a ruptured blood vessel

Hallucination – Abnormal perceptual experience

Hemianopia – Loss of sight affecting one half of the visual field (e.g. bitemporal hemianopia)

Hemiparesis – Weakness of one side of the body

Hemiplegia – see Hemiparesis

Hepatolenticular degeneration (Wilson’s disease) – Inherited disease of copper metabolism affecting the liver and brain

Herpes zoster – Virus causing shingles (q.v.)

Huntington’s disease – Inherited degenerative disease of the brain causing chorea (q.v.) and dementia (q.v.)

Hydrocephalus – Abnormal amount of cerebrospinal fluid within the ventricles of the brain

Hyperacusis – Increased hearing sensitivity

Hyperreflexia – Abnormal increase in reflex activity

Hypertonia – Abnormal increase in muscle tone

Hypertrophy – Enlargement of tissues

Hypothyroidism – Underactivity of the thyroid gland causing reduced release of thyroid hormone

Hypotonia – Abnormal decrease in muscle tone

Idiopathic – Of unknown cause

Infarction – Death of tissue resulting from impairment of its circulation

Intervertebral – Between two vertebrae

Ipsilateral – Relating to the same side

Kinaesthesia – Perception of movement

Lamina – A thin layer (e.g. internal medullary lamina)

Lesion – Site of disease or damage

Lobectomy – Surgical resection of lobe of the brain

Lumen – A space or cavity

Lymphoma – Tumour of the lymphoid system

Magnetic resonance imaging (MRI) – Technique to image structure that does not employ ionising radiation

Mastication – The act of chewing

Miosis – Pupillary constriction

Meninges – connective tissue sheaths surrounding the CNS, namely dura mater, arachnoid mater and pia mater

Meningitis – Inflammation of the meninges

Meningioma – A tumour arising from the fibrous coverings (meninges) of the brain

Metastasis – Spread of tumour to distant sites

Microglia – A type of neuroglial cell (q.v.), having a mainly phagocytic function in the response to brain damage or injury

Migraine – Paroxysmal headache

Motor neurone disease – Degenerative disease of upper and lower motor neurones, causing paralysis

Multiple sclerosis – Immune disease of the CNS, causing relapsing disorder of nervous function

Muscular dystrophy – Inherited degeneration of muscles, causing progressive paralysis

Myasthenia gravis – Immune disorder of the neuromuscular junction, causing muscular fatigue

Myelin – A sheath of protein and phospholipid around the axons of certain neurones

Myopathy – Disease of muscle

Narcolepsy – Paroxysmal sleep attacks

Necrosis – Death of tissue

Neoplasia – Tumorous overgrowth of tissue

Neurofibromatosis – Inherited disease causing tumours of meninges, CNS, peripheral nerves and skin

Neuroglia (neuroglial cell) – non-neural supporting cells of the CNS comprised of oligodendrocytes, astrocytes, microglia and ependymal cells (q.v.)

Neuroma – Tumour derived from nerve cells

Neurone – The principle functional cell of the nervous system, specialised to integrate and transmit nerve impulses

Neuropathy – Disease of nerve cells

Neurosyphilis – Infection of the nervous system by a spirochaete

Neurotransmitter – Chemical substance stored within vesicles (q.v.) in presynaptic nerve endings and released on depolarisation to act upon postsynaptic receptors

Nociception – Sensitivity to noxious stimuli

Nucleus – Structure within a cell that contains chromosomal DNA; also a collection of nerve cell bodies within the CNS (e.g. dentate nucleus)

Nystagmus – To-and-fro movements of the eyes

Oedema – Swelling caused by accumulated fluid

Oligodendrocyte (oligodendroglia) – A type of neuroglial cell (q.v.) that produces the myelin sheath in the CNS

Oligodendroglioma – Tumour derived from oligodendroglia

Ophthalmoscopy – Clinical examination of the eye with an ophthalmoscope

Pallidum – Globus pallidus

Palsy – Weakness

Papilloedema – Swelling of the optic nerve(s)

Paraesthesia – Tingling sensations (‘pins and needles’)

Paralysis – Muscle weakness of varying severity

Paraphasia – Use of incorrect word

Paraplegia – Weakness or paralysis of the legs

Paresis – Muscular weakness

Parkinson’s disease – Disease of the basal ganglia causing akinesia (q.v.), rigidity (q.v.) and tremor (q.v.)

Paroxysm – Sudden attack

Peripheral nervous system – All parts of the nervous system excluding the brain and spinal cord (CNS)

Photophobia – Intolerance to light

Pia mater – Innermost of the three meningeal layers that envelop the central nervous system

Plexus – Structure consisting of interwoven nerves (e.g. brachial plexus) or blood vessels (e.g. choroid plexus)

Poliomyelitis – Viral infection of motor neurones of the spinal cord and brain stem

Positron emission tomography (PET) – Technique for imaging the function of the brain

Prolapse – Displacement from normal anatomical position

Proprioception – The detection of position and movement of body parts

Pseudobulbar palsy – Weakness of the tongue, pharynx and larynx caused by disease of the corticobulbar tracts

Psychosis – Abnormal mental state with altered precepts (hallucinations) and false ideas (delusions)

Ptosis – Abnormal drooping of the eyelid

Quadriplegia – Paralysis affecting all four limbs

Radiculopathy – Disease of the nerve roots

Receptor – Specialised element of the cell membrane that binds neurotransmitter substances (or exogenous drugs) bringing about a change in membrane permeability or an intracellular response

Resting potential – The electrical potential across the membrane of a nerve cell at rest

Rheumatic fever – Immune disease of the joints, heart and brain following bacterial infection

Rigidity – Increased resistance to passive movement of the limbs throughout their range

Schizophrenia – Disease of the brain causing psychosis (q.v.)

Seizure – Sudden disturbance of consciousness or sensorimotor function

Shingles – Infection of the ganglia of cranial and spinal nerves by herpes zoster virus (q.v.)

Single photon emission tomography (SPECT) – Technique for imaging the function of the brain

Somatic – Relating to body parts other than the viscera

Somatotopic – The orderly representation of body parts in the CNS

Spasticity – Increased resistance to passive movement of the limbs when muscles are initially stretched

Spondylosis – Degeneration of the spine

Stroke – Sudden neurological deficit caused by disease of the circulation to the brain

Sydenham’s chorea – Manifestation of rheumatic fever (q.v.) affecting the basal ganglia and causing involuntary movements

Synapse – The gap between neurones across which nerve impulses pass by release of a neurotransmitter

Synaptic vesicle – Structure within the presynaptic ending that contains neurotransmitter substance which is released on depolarisation

Syncope – Fainting attack

Syndrome – Group of signs and symptoms which characterise a disease

Syringobulbia – Expanding cavity (syrinx) within the medulla

Syringomyelia – Expanding cavity within the spinal cord

Syrinx – An abnormal cavity in the spinal cord

Thalamotomy – Neurosurgical destruction of part of the thalamus

Terminal bouton – specialised presynaptic ending of an axon

Thrombosis – Coagulation of blood in artery or vein

Tract – An aggregation of nerve cell processes having more or less the same origin and destination (e.g. corticospinal tract)

Tremor – Trembling of head or limbs

Tumour – A swelling or morbid enlargement; a mass of abnormal tissue resulting from uncontrolled cell growth (neoplasm)

Vesicle – see Synaptic vesicle