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
Abduction - Latin ab = from, and ductum = led,
hence, movement from; verb - abduct.
Abductor - (L. abducere, to move away). A muscle that draws a structure away from the axis of the body or one of its parts, e.g. lateral rectus muscle.
- Latin ab = from, and errare = to wander, hence, deviating from normal.
- A localized collection of pus caused by suppuration buried in tissues, organs
or confined spaces. Usually due to an infective process.
Accessorius - (L. accessorius, to move toward). Accessory or supernumerary. Also denoting specific muscles.
- (L. accessorius, to move toward). Supernumerary, adjuvant. It is also an
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.
- Latin acetum = vinegar (cf. acetic), and abulum = small receptacle, hence, a
vinegar cup, hence, the socket for the head of the femur, adjective -
Achalasia - Constriction of the lower portion of the food pipe
(oesophagus) due to inability of the sphincter muscles to relax. Symptoms
include difficulty swallowing, chest pain, vomiting and heartburn.
Achlorhydria - The absence of hydrochloric acid from the gastric juice.
Acoustic - adjective, Greek akoustikos, related to hearing.
- 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.
- (L. adducere, to bring forward). A muscle that draws a structure toward the axis of the body or one of its parts, e.g. adductor pollicis.
Adenocarcinoma - One of the most common primary lung carcinomas, which
appears to be increasing in incidence, and now may be more common than squamous
cell carcinoma. This tumor is usually peripheral in location and often is
associated with scarring, leading to pleural puckering. This neoplasm may vary
in histologic appearance with some tumors having well-formed glands, others
having a papillary architecture, and yet others being less differentiated and
having a solid appearance.
Adenoid - Greek aden = a gland, eidos = shape or form.
- Latin ad = to, and haesus = stuck, hence, stuck to, e.g., interthalamic adhesion - variable and functionally insignificant.
- Latin adeps = fat, hence fatty
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
Adventitia - The outermost connective tissue covering of any organ, vessel, or other structure not covered by a serosa; instead, the covering is properly derived from without (i.e., from the surrounding connective tissue) and does not form an integral part of such organ or structure.
- 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.
Aflatoxins - A harmful substance made by certain types of mold (Aspergillus flavus and Aspergillus parasiticus) that is often found on poorly stored grains and nuts. Consumption of foods contaminated with aflatoxin is a risk factor for primary liver cancer.
- Latin = eminence of the nose.
Agnogenic - Synonym: idiopathic—refers
to a disease or condition of unknown cause or origin.
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.
Alae(l. ala, wing) - Relating to a muscle of the nose, and others.
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.
- Latin albus = white
Albicans - Latin = becoming white; albus = white
Albuginea - Latin albus = white, Greek gen = form, hence, like boiled
white of an egg.
Algorithm - The term algorithm (pronounced
AL-go-rith-um) is a procedure or formula for solving a problem.
- adjective, Latin alimentum = food, e.g., alimentary canal.
Allantois - Greek allantos = sausage, eidos = like, form.
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.
- 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).
Amitotic - Relating to or marked by
amitosis -- an unusual form of nuclear division, in which the nucleus simply
constricts, rather like a cell without chromosome condensation or spindle
formation. Partitioning of daughter chromosomes is haphazard.
Resembling an amoeba specifically in moving or changing in shape by means of
Ampulla - Latin = a two-handed flask, a local
dilatation of a tube. A saccular anatomic swelling or pouch.
- adjective, Greek amygdala = almond, and eidos = shape or form, hence,
amygdaloid body is an almond-shaped mass.
Amylacea - Greek amylon = starch, hence, starchy.
Enzyme, also called diastase. It is found in both plants and animals.
- Greek an = negative, and aisthesis = sensation, hence, loss of sensation;
adjective - anaesthetic.
Anal verge - The external or distal boundary of the anal canal.
- 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).
Anaplasia - Lack of differentiated features in a cancer cell, characterized by
cellular pleomorphism (variation in size and shape of cells and their nuclei),
enlarged and hyperchromatic nuclei, prominant nucleoli, atypical mitoses, and
bizarre cells, including giant cells.
Anastomosis - Greek ana = of each,
and stoma = mouth, hence the end-to-end continuity of 2 vessels; adjective -
anastomotic. An opening created by surgical, traumatic or pathological means
between two normally separate spaces or organs.
Anatomy - Greek ana =
up, and tome = a cutting, hence cutting up of a body (c.f. dissection). The
study of the structure and relationship between body parts.
Greek ancon = elbow, hence the muscle attached to the (lateral surface of the)
olecranon. (G. ankon, elbow). Musculus anconeus.
Anemia - Reduction in
total circulating red blood cell mass, diagnosed by a decrease in hemoglobin
concentration. Anemic patients have low oxygen-carrying capacity of the blood,
with resultant tissue hypoxia. The clinical symptoms are related to the severity
of the anemia, and may include pallor, tachycardia, angina, light-headedness and
fatigue. Anemia may be due to increased blood loss, decreased red blood cell
production, or increased red blood cell destruction.
Aneuploid - Having a
chromosome number that is not an exact multiple of the haploid number.
- 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.
Angiosarcoma - Angiosarcomas are
uncommon malignant neoplasms characterized by rapidly proliferating, extensively
infiltrating anaplastic cells derived from blood vessels and lining irregular
blood-filled spaces. Specialists apply the term angiosarcoma to a wide range of
malignant endothelial vascular neoplasms that affect a variety of sites.
Angiosarcomas are aggressive and tend to recur locally, spread widely, and have
a high rate of lymph node and systemic metastases.
Anhidrosis - (anhydrosis, anidrosis) Greek an = negative, and hidros = sweat,
hence absence of sweating, typical of skin deprived of its sympathetic
Ani - (L. anus, anal oriface). Pertaining to a muscle that supports the anus.
- the region between the leg and the foot.
Annulus - diminutive of Latin
anus = ring, hence little ring.
Anomaly - A marked deviation from the
normal standard, especially as a result of congenital defects.
The uncontrolled lack or loss of the appetite for food.
- Latin a
handle or loop. Applicable to nerves.
Anserinus - Latin anser = a goose, hence like a goose, plural - anserina.
- Greek anti = against, and agonistes = rival, hence a muscle which may oppose
Antagonistic hormones - hormones that act to return body conditions to within acceptable limits from opposite extremes.
- Latin ante = before, and flexere = to bend, hence anterior angulation between
the body and cervix of the uterus.
Anterior - comparative of Latin ante
= before, in front.
Anteversion - Latin ante = before, and versum = turned, hence, the
anterior angulation between cervix uteri and the vagina.
- Antibodies are special proteins that are part of the body's immune system. White blood cells make antibodies to neutralize harmful germs, or other foreign substances, called antigens. Antibodies are "good guys" that fight inside your body, protecting you from "bad guys" like bacteria and viruses.
- (L. anticus, anterior). Designating a muscle as placed anteriorly, e.g.
Antidromic - adjective, Greek a = negative, and dromos
= current, hence conducting in the opposite direction to the usual.
- An antigen is a substance that can trigger an immune response, resulting in
production of an antibody as part of the body's defense against infection and
disease. Many antigens are foreign proteins (those not found naturally in the
body). An allergen is a special type of antigen which causes an IgE antibody
Antrectomy - Removal of the walls of an antrum.
- A general term for cavity or chamber which may have specific meaning in reference certain organs or sites in the body. The antrum of the stomach (gastric antrum) is a portion before the outlet which is lined by mucosa which does not produce acid. The paranasal sinuses can be referred to as the frontal antrum, ethmoid antrum, and maxillary antrum.
- diminutive of Latin anus = ring, hence little ring.
Anus - diminutive
of Latin anus = ring, hence little ring.
Aorta - The largest artery in
the body which has its origin at the heart. It gives off branches to the
extremities, neck and major organs for the purpose of supplying oxygenated
Aplastic - Lacking in cell production, as in aplastic anaemia.
Aponeurosis - Greek apo = from, and neuron = tendon (later applied to nerve cell
and its fibres), used for sheet-like tendons. Adjective - aponeurotic.
- Greek apo = from, and physis = growth, hence, a bony process - reserved for
the articular process of a vertebra; adjective - apophysial.
Latin appendere = to hang on, supplement.
Appendicular skeleton - the
bones that make up the limbs, basically your arms, legs, hands, and feet.
Appendix - Latin appendere = to hang on, supplement.
Apposition - Latin appositus = placed at, hence, in contact, in juxtaposition.
- 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 - 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.
- (L. arcus, a bow). Any structure resembling a bent bow or an arch.
- Greek archi = first, hence the oldest part of the cerebellum, which is the
Archaeopallium - Greek archi = first, and pallium = cloak, hence the cortex
which developed first in vertebrates. Often synonymous with hippocampal
Archicerebellum - Greek archi = first, hence the oldest part
of the cerebellum, which is the flocculonodular lobe.
Greek archi = first, and pallium = cloak, hence the cortex which developed first
in vertebrates. Often synonymous with hippocampal formation.
Latin arcuatum = curved or arched.
Arcus - Latin an arch, Latin arcuatum = curved or arched.
Area - a part
of a surface.
Areola - Latin small, open space.
Arm - the upper
limb, between shoulder and elbow.
Arrector - Latin adrectus = raised,
hence, arrector pili = a hair-raising muscle.
Arteries - carry blood
away from the heart.
Artery - Latin arteria (which originally meant air-
or wind-pipe, and later a blood vessel carrying blood away from the heart).
- Latin artus = joint, hence, articulate - to form a joint.
Articulationis - (L. articulationes, the forming of new joints of a vine).
Pertaining to muscles that insert into a joint capsule.
Arytenoid - Greek
arytaina = pitcher, and eidos = shape or form, hence the arytenoid cartilage
because it curves like a spout. (G. arytenoideus, ladel-shaped). Pertaining to
muscles attached to this laryngeal cartilage.
Ascites - Abnormal buildup
of fluid in the abdomen. Ascites can occur as a result of severe liver disease.
- a view of more than one surface.
Aspera - Latin rough.
Asterion - Greek asterios = starry.
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
Atelectasis - Absence of air in the alveolar spaces resulting
in incomplete expansion of the lungs at birth or collapse of the lungs of an
Atlanto - (G. Atlas, in Greek mythology a Titan who supported the
world on his shoulders). Relating to muscles attached to the second cervicle
vertebra, the atlas.
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,
Atloideus - See Atlanto
Atom - the smallest quantity of an element that
still possesses the characteristics of the element.
Atp (adenosine triphosphate)
- a common source of activation energy for metabolic reaction.
Greek a = negative, and tresis = a hole, hence an absence or closure of a body
orifice or tubular organ
Atria - the two upper chambers of the heart.
- Latin = entrance hall, adjective - atrial.
Atrophy - Greek a = negative, and trophe = food, hence wasting
from starvation. A wasting away, a diminution in the size of a cell, tissue,
organ or part.
Atypia - State of being not typical.
Latin audire = to hear, hence, pertaining to the ear.
Auricle - Latin
auricula = a little ear.
Auricularis - (L. auricularis, the external
ear). Pertaining to muscles that attach to the external ear. Also referring to
the fifth digit of the hand because of its use in cleaning the external auditory
Auscultate - Latin ausculto = to listen to, hence, auscultation,
the act of listening to a bodily activity.
Autonomic - adjective, Greek auto = self, and nomos = law, hence self-regulating.
Autonomic nervous system (ans)
- controls the activities of organs, glands, and various involuntary muscles.
- the bones that revolve around the vertical axis of the skeleton, basically the
spine and skull.
Axilla - Latin armpit.
Axillary - (L. axilla, armpit). Pertaining to muscles that are found in the
region of the armpit, e.g. axillary arch muscle.
Axis - Latin axis = the
central line of a body or part thereof, especially the imaginary line around
which rotation takes place.
Axon - Latin axis = axis, hence the main
process of a neuron conducting impulses away from the cell body.
Azygos - adjective, Greek a = negative, and zygos =
paired, hence, unpaired. (G. a, without + zygon, yoke). Any unpaired muscle.