abdomen: Latin abdomen = the belly, the part of the trunk between thorax and the perineum, adjective - abdominal.
abducent: Latin ab = from, and ducens = led, hence, moving from, or effecting separation.
abduction: Latin ab = from, and ductum = led, hence, movement from; verb - abduct.
aberrant: Latin ab = from, and errare = to wander, hence, deviating from normal.
accessory: adjective, Latin accessum = added, hence, supplementary.
accommodation: Latin ad = to, and modus = measure, hence, adaptation of the optical power (focussing) of the eye for shorter distances.
acetabulum: Latin acetum = vinegar (cf. acetic), and abulum = small receptacle, hence, a vinegar cup, hence, the socket for the head of the femur, adjective - acetabular.
acoustic: adjective, Greek akoustikos, related to hearing.
acromion: Greek akros = summit (cf. Acropolis) and omos = shoulder, hence, the tip of the shoulder.
adduction: Latin ad = to, and ductum = led, hence, movement towards; verb - adduct.
adenoid: Greek aden = a gland, eidos = shape or form.
adhesion: Latin ad = to, and haesus = stuck, hence, stuck to, e.g., interthalamic adhesion - variable and functionally insignificant.
aditus: Latin ad = to, towards, iter = a way, hence an opening or entrance.
adrenal: Latin ad = towards, at, ren = kidney, hence situated near the kidney (see suprarenal)
adrenergic: adjective, Latin ad = at, ren = kidney, and Greek ergon = work, hence, stimuli which cause the adrenal (suprarenal) gland to produce adrenaline. Used to specify neurons or pathways which use adrenaline as a transmitter.
afferent: adjective, Latin ad = to, and ferent = carrying (cf. ferry), hence, carrying to, e.g., axons carrying information from retina to lateral geniculate nucleus are afferents to that nucleus.
agonist: Greek agonistes = rival, hence, a muscle in apparent contest with another. Used for a prime mover.
ala: Latin wing, hence a wing-like process; plural - alae.
alaeque: Latin ala = wing (ala of nose), suffix -que = and, hence levator labii superioris alaeque nasi muscles = lifter of the upper lip and ala of nose.
allocortex: Greek allos = other (than usual), and Latin cortex = bark, hence non-laminated external grey matter. It refers to paleo- or archi-cortex, as distinct from neocortex.
alveolus: Latin a basin, hence any small hollow. Plural - alveoli, adjective - alveolar.
alveus: Latin = tray. The allusion is unclear. The alveus is a layer of fibres on the free surface of the hippocampus.
ambiguus: adjective, Latin = doubtful (nucleus ambiguus).
ampulla: Latin = a two-handed flask, a local dilatation of a tube.
amygdaloid: adjective, Greek amygdala = almond, and eidos = shape or form, hence, amygdaloid body is an almond-shaped mass.
anaesthesia: Greek an = negative, and aisthesis = sensation, hence, loss of sensation; adjective - anaesthetic.
analgesia: Greek an = negative, and algesis = pain, hence insensibility to pain; adjective - analgesic.
analogous: Greek ana = up, apart, towards, and logos = word. A part with similar function through different morphology e.g., fish gills and mammalian lungs (c.f. homologous).
anastomosis: Greek ana = of each, and stoma = mouth, hence the end-to-end continuity of 2 vessels; adjective - anastomotic.
anatomy: Greek ana = up, and tome = a cutting, hence cutting up of a body (c.f. dissection).
anconeus: Greek ancon = elbow, hence the muscle attached to the (lateral surface of the) olecranon.
aneurysm: Greek angeion = blood vessel, and eurys = wide, hence a pathological dilatation of a blood vessel.
angiography: Greek angeion (v.s.) and graphe = a record, hence a picture of a blood vessel which has been injected with a dye or radiopaque material.
anhidrosis: (anhydrosis, anidrosis) Greek an = negative, and hidros = sweat, hence absence of sweating, typical of skin deprived of its sympathetic innervation.
aorta: Latin aorta, from Greek aorte = literally 'what is hung up,' from aeirein 'to lift, heave, raise,' of uncertain origin. Originally applied by Aristotle to the great artery of the heart, earlier by Hippocrates to the bronchial tubes.
aponeurosis: Greek apo = from, and neuron = tendon (later applied to nerve cell and its fibres), used for sheet-like tendons. Adjective - aponeurotic.
apophysis: Greek apo = from, and physis = growth, hence, a bony process - reserved for the articular process of a vertebra; adjective - apophysial.
appendage: Latin appendere = to hang on, supplement.
appendix: Latin appendere = to hang on, supplement.
apposition: Latin appositus = placed at, hence, in contact, in juxtaposition.
aqueduct: Latin aqua = water, and ductus = drawn or led off, hence a channel for conducting fluid, e.g. the cerebral aqueduct of the midbrain, which transmits fluid from the 3rd to the 4th ventricle.
arachnoid: adjective, Greek arachne = spider, and eidos = shape or form, hence like a spiders web. This middle layer of the three meninges is spread web-like over the brain when the dura has been removed.
arbor vitae: Latin arbor = tree, and vita = life, hence, resembling the tree of life. This colourful term is used to describe the pattern of cerebellar folia seen in a median section.
archaeocerebellum: Greek archi = first, hence the oldest part of the cerebellum, which is the flocculonodular lobe.
archaeopallium: Greek archi = first, and pallium = cloak, hence the cortex which developed first in vertebrates. Often synonymous with hippocampal formation.
archicerebellum: Greek archi = first, hence the oldest part of the cerebellum, which is the flocculonodular lobe.
archipallium: Greek archi = first, and pallium = cloak, hence the cortex which developed first in vertebrates. Often synonymous with hippocampal formation.
archistriatum: Greek archi = first, and Latin striatum = streaked or fluted.
astrocyte: Greek astron = star, and kytos = cell, hence a star-shaped (neuroglial) cell.
ataxia,: Greek a = negative, and taxis = order, hence inability to co-ordinate the voluntary muscles.
atlas: Greek atlao = I sustain. Atlas was a mythical god who sustained the globe on his shoulders. The 1st vertebra sustains the skull, and its upper surface bears 2 concavities which suggest Atlas' palms, not shoulders.
atresia: Greek a = negative, and tresis = a hole, hence an absence or closure of a body orifice or tubular organ
atrium: Latin = entrance hall, adjective - atrial.
atrophy: Greek a = negative, and trophe = food, hence wasting from starvation.
auditory: Latin audire = to hear, hence, pertaining to the ear.
