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.

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.

Aberrant - Latin ab = from, and errare = to wander, hence, deviating from normal.

Abscess - 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.

Accessory - (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.

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.

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.

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.

Adductor - (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.

Adhesion - Latin ad = to, and haesus = stuck, hence, stuck to, e.g., interthalamic adhesion - variable and functionally insignificant.

Adipose - 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 transmitter.

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.

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.

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.

Agger nasi - 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.

Alba - 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.

Alimentary - 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.

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).

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.

Amoeboid - Resembling an amoeba specifically in moving or changing in shape by means of protoplasmic flow.

Ampulla - Latin = a two-handed flask, a local dilatation of a tube. A saccular anatomic swelling or pouch.

Amygdaloid - adjective, Greek amygdala = almond, and eidos = shape or form, hence, amygdaloid body is an almond-shaped mass.

Amylacea - Greek amylon = starch, hence, starchy.

Amylase - Enzyme, also called diastase. It is found in both plants and animals.

Anaesthesia - Greek an = negative, and aisthesis = sensation, hence, loss of sensation; adjective - anaesthetic.

Anal verge - The external or distal boundary of the anal canal.

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).

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.

Anconeus - 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.

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.

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 innervation.

Ani - (L. anus, anal oriface). Pertaining to a muscle that supports the anus.

Ankle - 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.

Anorexia - The uncontrolled lack or loss of the appetite for food.

Ansa - Latin a handle or loop. Applicable to nerves.

Anserinus - Latin anser = a goose, hence like a goose, plural - anserina.

Antagonist - Greek anti = against, and agonistes = rival, hence a muscle which may oppose an agonist.

Antagonistic hormones - hormones that act to return body conditions to within acceptable limits from opposite extremes.

Anteflexion - 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 - 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.

Anticus - (L. anticus, anterior). Designating a muscle as placed anteriorly, e.g. serratus anterior.

Antidromic - adjective, Greek a = negative, and dromos = current, hence conducting in the opposite direction to the usual.

Antigen - 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 response.

Antrectomy - Removal of the walls of an antrum.

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.
 
Anulus - 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 blood.

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.

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.

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.

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 - 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.

Arch - (L. arcus, a bow). Any structure resembling a bent bow or an arch.

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.

Arcuate - 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).

Articulation - 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.

Aspect - 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 muscles.

Atelectasis - Absence of air in the alveolar spaces resulting in incomplete expansion of the lungs at birth or collapse of the lungs of an adult.

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, not shoulders.

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.

Atresia - 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.

Atrium - 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.

Auditory - 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 meatus.

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.

Axial skeleton - 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.