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from the Department of Anatomy, University of New South Wales, Sidney Australia,




Pacchioni, Antonio. 1665-1726 Rome & Tivoli anatomist; Pacchionian bodies = arachnoid granulations (1705), q.v.


pachymenix G. pachys = thick + menix = a membrane; the dura mater.


Pacini, Filippo. 1812-1883 Pisa & Florence anatomist; lamellated (onion-like) corpuscles of Vater-Pacini in skin (1840); tendon sheaths.


palate L. palatum = roof of mouth.


palisade L. palus = stake; like a fence of stakes.


palmate folds cf. plicae palmatae.


palpebral adj. L. palpebra = eyelid, from L. palpitare = to move quickly.


pampiniform adj. L. pampineus = full of vine tendrils + forma = shape; a tangled mass of veins in spermatic cord.


pancreas G. pan = all + kreas = edible flesh; a sweetbread (though less of a delicacy than the thymus); intestinal exocrine & endocrine gland.


pancreatic islets small islands or clusters of endocrine cells in pancreas; cf. Langerhans.


panniculus adiposus L. = a little piece of cloth, a rag + L. adeps = fat (adiposus is a L. corruption); the hypodermis (Berengarius, 1524).


Paneth, Josef. 1857-1890 Breslau & Vienna physiologist; P. cells (1887) = eosinophilic cells at base of intestinal crypts of Lieberkühn.


papilla (-ae) L. = a teat, a nipple; a nipple-like projection, e.g., on the tonge (Malpighi, c. 1670; cf. circumvallate, filiform, foliate, fungiform, vallate); duodenal papilla (containing duodenal ampulla); optic papilla; renal papilla (Berengarius, c. 1480-1550).


papillary adj. L. "; of the most superficial layer of the dermis, containing fine collagen fibres immediately under the epidermis; of cardiac muscle fibres that form eminences on the inner surface of the ventricles.


para- G. = beyond, beside, near.


paradidymis G. " + didymos = testicle; remains of mesonephros situated on the spermatic cord above the epididymis= organ of Giraldès, q.v.; also = organ of Waldeyer.


paraganglion (-ia) G. " + ganglion = a swelling; clumps of chromaffin tissue scattered alongside sympathetic nerves in thorax and abdomen; cf. Zuckerkandl.


parakeratin G. " + keras = horn; a type of keratin formed in superficial cells at sites of abrasion and rapid epithelial renewal, e.g., gingiva, tongue, tonsillar crypts, palate.


parametrium G. " + metra = womb, uterus; loose, fatty connective tissue in the broad ligament around uterus.


parathyroid G. " + thyreos = a shield (cf. thyroid gland); gland lying "alongside" the thyroid.


parenchyma G. " + enkeim = to pour in; the essential functional cells of an organ as opposed to its stroma, q.v. (NB. the accent is on the "e", not the "y").


paries (-ities) L. paries = a wall; cf. body wall around a coelom q.v.


parietal adj. L. parietalis = relating to walls; the outer region or wall as opposed to visceral.


paroöphoron G. para = beside + öon = egg + phoros = bearing; minute tubules of the mesosalpinx lying adjacent to the uterine tube, derived from caudal part of embryonic mesonephros.


parotid G. para = beside + otos = of the ear; a salivary gland.


parous L. pario = I bear (children).


pars L. = a part; a part of an organ, or structure, e.g., pars iridica retinae; pars nervosa; pars distalis, etc.


PAS periodic acid & Schiff's reagent; histochemical stain for carbohydrates involving production of aldehyde groups by initial treatment with periodic acid, then reaction of these groups with Schiff's reagent to produce a magenta colour.


pearl 1. a concretion formed around a grain of sand, etc.; 2. a small tough mass of material, e.g., a keratin pearl, an enamel pearl, a pearl of mucus in sputum.


pectinate adj. L. pecten = a comb; musculi pectinati = muscular bands passing forwards from crista terminalis in wall of right atrium (including the crista, resembles a comb).


pedicel L. pediculus = a little foot, dim. L. pes; stem attached to growing process; pedicles of podocytes in renal glomerulus.


pedicle L. pediculus = a little foot (dim. of L. pes = a foot); stem or connecting stalk of a tumour; bony process connecting the lamina of a vertebra to its body; renal pedicle = renal "stalk".


pellucidum L. per = through + lucere = to shine; translucent; e.g., zona pellucida of ovarian follicle; septum p. of brain.


pelvis L. = a basin.


penicillar adj. L. penicillum = a paint-brush, from L. penna = a feather; branching into many short segments, as in the penicillar arterioles of the spleen


penis L. = a tail.


pepsinogen G. pepis = digestion + gennan = to produce; a precusor of pepsin = enzyme that aids digestion.


peri- G. = around, about.


pericardium G. " + kardia = heart; of two types: visceral (covering the heart) and parietal (lining the pericardial sac).


perichondrium G. " + chondros = granule, gristle, cartilage; connective tissue and cellular layer surrounding cartilage.


pericyte G. " + kytos = hollow vessel; mesenchymal cell adjacent to capillaries.


perikaryon G. " + karyon = nucleus; body of a nerve cell surrounding its nucleus; soma, q.v.


perilymph G. " + L. lympha = clear fluid; a bastard term (from G. & L.) for fluid in bony labyrinth surrounding the membranous labyrinth; cf. endolymph.


perimysium G. " + mys = muscle; connective tissue around a muscle fascicle.


perineurium G. " + neuron = sinew; a lamellated sheath of connective tissue and cells around a nerve fascicle.


periodontal ligament or membrane G. " + odons = tooth; fibro-elastic tissue (including Shapey's fibres) joining the tooth to its alveolar socket in the bone.


periodontium G. " ; all the tissue around the root of a tooth.


periosteum G. " + osteon = bone; fibrous membrane covering bone, attached to bony matrix by Sharpey's fibres.


peripheral nervous system nerves and nerve cells outside the central nervous system; abb. PNS.


peristalsis G. " + stalsis = a contraction, from stellein = to constrict; progressive contractile wave along body tubes (Culpeper, 1655); adj. peristaltic.


peritoneum G. peri = around + teinein = to stretch around; membrane stretched around the lining of the abdominal sac and ensheathing some viscera; adj. peritoneal.


Perls, Max, 1843-1881 German pathologist; Perls' test for hemosiderin using the Prussian blue reaction/stain.


Peyer, Johann Konrad. 1653-1712 Schaffhausen, professor of Logic, Rhetoric & Natural Science; P.'s patches = aggregated lymphatic nodules in terminal ileum (1673).


phagocytosis G. phagein = to eat + kytos = cell + osis = a condition of; process by which a cell engulfs foreign particles, dead material, etc.


phalangeal adj. G. phalanx = a band of soldiers (a Greek army division in battle order); phalangeal cells = sustentacular cells in organ of Corti whose processes extend upwards between the hair cells like fingers; Deiters, q.v.


pharynx G. = throat; adj. pharyngeal (? G. pharanx = a cleft, chasm).


pheomelanin G. phaios = dusky red + melas = black; pigment found in red hair.


phlegm G. phlegma = thick mucus; one of four humours of early physiology; thought to be a discharge from brain; cf. pituitary.


Phloxine red cytoplasmic dye.


photoreceptor G. phos = light + L. recipio = I receive; bastard term for light-sensitive cells in retina.


physic G. physikos = natural; the art of medicine.


pia mater L. pius = soft, faithful (L. pietas was one of the cardinal virtues) + mater = mother; delicate vascular membrane which adheres to surface of brain and spinal cord, faithfully following their contours.


picric acid a yellow dye.


pilomotor L. pilus = a hair + motor = mover; causing hair movement; cf. arrector pili.


pineal L. pinea = pine cone; cone-shaped gland of the brain; cf. conarium.


pinocytosis G. pinein = to drink + kytos = cell + osis = a condition of; process by which a cell takes in droplets of fluid.


pituitary L. pituita = phlegm, snot; gland at base of brain thought to be responsible for nasal secretion, via perforations in cribriform plate of ethmoid (Vesalius, c. 1560).


placenta L. = a flat cake, from G. plax- = flat- ; (Ge. Mutterkuchen = "mother-cake" = placenta).


plasma G. = a thing formed; liquid component of lymph, blood; NB. plasma membrane = cell membrane.


plasmodium G. " + -oeides = like; a continuum of protoplasm in which many nuclei are embedded, e.g., placental plasmodium = syncytiotrophoblast.


plasmolysis G. " + lysis = solution; shrinkage of a cell due to osmotic pressure.


platelet OF. plate = flat; small, non-nucleated discoids in circulating blood derived from fragmentation of megakaryocytes.


pleomorphic G. pleon = more + morphe = form; varying in shape and size.


pleura (-ae) G. = rib, side; serous membrane covering lungs and lining thorax; parietal and visceral pleurae.


plexus (-i) L. = a braid; a woven network of linear structures, especially nerves.


plica (-ae) a corruption from L. plicare = to fold; in13th century a scalp infection endemic in Poland was called plica polonica (Polish plait); any kind of fold.


plicae circulares L. = circular folds; actually transverse folds that are not circular in small intestine = valves of Kerckring, q.v.


plicae palmatae L. " + palmatae = like palm trees; flat mucosal folds like palm fronds in uterine cervical canal.


podocyte G. podos = foot + kytos = hollow vessel (cell); cell in renal glomerulus with many feet (foot processes) and pedicels.


-poiesis G. = making or producing; suffix as in haemopoiesis, leucopoiesis.


polar body the smaller daughter nucleus of a fertilised dividing ovum.


polkissen Ge. = pole cushion; extraglomerular mesangial cells at vascular pole.


polychromatophilic G. polys = many + chroma = colour + philein = to love.


polymorphonuclear (abb. polymorph) adj. G. " + morphe = form; having a nucleus with different shapes (multiple lobes), e.g., a neutrophilic leucocyte.


polyploid G. " + -oeides = form of; G. = manifold; having several sets of chromosomes; cf. diploid, haploid, aneuploid.


polysome aggregation of ribosomes.


pore L. porus = hole, aperture; nuclear pore = aperture in nuclear envelope.


porta hepatis L. porta = door + hepatis = of liver; fissure at hilum of liver; NB. portal vein was vein entering porta hepatis.


porta lienis L. porta = door + L. lienis = of the spleen; fissure at hilum of spleen.


portal adj. L. portare = to carry; of a vascular system carrying blood between infundibulum and adenohypophysis = hypothalamohypophyseal portal system. (NB. portal vein is named from L. porta = door).


postcapillary venules smallest vessels which drain capillary beds into collecting venules.


postsynaptic membrane region of membrane on a second cell opposite a synaptic terminal of the first cell; cf. synapse.


prepuce L. praeputium = prepuce or covering of glans penis (? from G. pro + posthe = penis; or ? L. puteo = I stink, from smell of smegma, q.v.; thus uncleanliness is figuratively termed praeputia).


presynaptic membrane region of a nerve cell at the synapse of a terminal bouton; cf. synapse.


progesterone G. pro = before + L. gerere = to bear; hormone from corpus luteum preparing the uterus for pregnancy.


prophase G. pro = before + phasis = phase, from phainein = to appear, to show; first stage in mitosis of somatic cells.


prostate G. pro = before + G. istanai = to stand, or ? L. statum = stood; standing before; male gland at base of ("before") bladder; Aristotle uses prostatai chirsoedeis = varicose prostate = seminal vesicles; Herophilus (c. 300 BC) uses prostatai adenoeideis = glandular prostate; Galen (c. 180 AD) uses prostatai for whole complex of seminal vesicles and prostate, based on animal dissections.


protoplasm G. protos = first + plasma = a thing formed; living matter (Purkinje).


proximal L. proxime = nearest (to the head, to a source, etc.); opposite to distal, q.v.


psammoma G. psammos = sand + oma = tumor; laminated concretions found in the pineal gland (cf. brain sand, acervulus)


pseudopodium (-ia) G. pseudos = false, fraud + podos = foot; temporary extension of a cell.


pseudostratified G. pseudos = false, fraud; simple epithelium where not all apical borders of cells reach lumen, thereby appearing to be stratified.


pseudounipolar G. " ; of a sensory ganglion cell, bipolar in embryo, but in adult having one axon which bifurcates into a central and a peripheral branch, the peripheral branch behaving as a dendrite, q.v.; cf. bipolar.


PTAH phosphotungstic acid and haematoxylin stain.


pubes L. = signs of manhood; hair of genital region.


pulmonary L. pulmo = lung.


pulp L. pulpa = soft, fleshy; central part of a tooth; parts of spleen; central part of a finger.


pulvinar L. = a cushioned couch (used by the gods); the raised posterior part of the thalamus, q.v.


punctum lacrimale L. = a point + of tears; opening of lacrimal duct at inner canthus of the eye.


pupil L. pupa = a girl, damsel, a doll (as in puppet); L. pupillae = small doll-like images seen mirrored in the eye, led to term pupilla for the central aperture of the iris (Cicero).


Purkinje (Purkyne), Johannes Evangelista, Ritter von. 1787-1869 Breslau pathologist, Prague physiologist; famous microscopist; early use of microtome; recognized importance of fingerprints (1823); P. cells = largest cerebellar neurones with extensive dendrites (1837); P. cells = conducting heart cells (1845); P. phenomenon = casting shadows of retinal blood vessels.


pyknotic G. pyknos = thick, close, compact + osis = condition; a nucleus with very condensed chromatin; a shrunken nucleus.


pylorus G. pyle = a gate + ouros = a guard; a gate-keeper, a janitor; distal, sphincteric orifice of stomach (Galen, c. 180 AD).


pyramidal cell G. pyramis = pyramid; cell in the cerebral cortex with a pyramid-shaped soma.


racemose L. racemosus = full of clusters (like a bunch of grapes); of compound exocrine glands whose grape-like acini are attached to branching ducts.


radicle L. radicula = a small root, dim L. radix; adj. radicular.


ramification L. ramus = a branch + facere = to make; branching.


Ramon y Cajal cf. Cajal.


ramus L. = a branch.


Ranvier, Louis Antoine. 1835-1922 Paris physician & histologist; nodes of R. (1875) = constrictions in nerve fibre between adjacent internodes; R.'s cross (1875) = intersection of stained glycocalyx & axoplasm forming a cross at site of node.


Rathke, Martin Heinrich. 1793-1860 Dorpat physiologist & pathologist, Königsberg anatomist & zoologist, embryologist; R.'s pouch = a recess anterior to the buccopharyngeal membrane in the embryo (1838).


RBC red blood cell or corpuscle.


rectum L. rectus = straight; terminal part of large intestine. NB. the rectum is straight in a rhesus monkey dissected by Galen (c. 180 AD), but curved in man.


refractile L. refractus = ability to turn back, i.e., bend the path of light.


refractive index 1. a measure of the extent to which a transparent object may bend the incident light path; 2. the ratio of velocity of light in vacuum (or air) to its speed in another medium; symbol h = 1.33 for water, 1.413 for lens of eye.


Reinke, Friedrich B. 1862-1919 German anatomist; crystalloids of R. = intracellular rod-shaped crystal-like structures in interstitial cells of testis (Leydig cells).


Reisseisen, Franz D. 1773-1828 R.'s muscle = smooth muscle fibres of microscopic bronchial tubes, i.e., bronchiolar muscle.


Reissner, Ernst. 1824-1878 Dorpat & Breslau anatomist, also Berlin; R.'s membrane (1851) = vestibular membrane of cochlea between scala media & scala vestibuli; R.'s duct = cochlea duct; R.'s fibre = fibre of jelly in central canal of spinal cord.


Remak, Robert. 1815-1865 German physician & neurologist; R.'s fibres (1838) = unmyelinated nerve fibres; R.'s ganglion = autonomic (as opposed to sensory) ganglion cells in heart; showed cell proliferation is due to division of existing cells, contrary to teaching of Schleiden & Schwann.


renal adj. L. ren = kidney.


renculus L. = a little kidney (dim. L. ren); a lobe of the kidney, defined partly by its papilla in the medulla.


resolving power closest distance between two points at which each can be seen separately, using naked eye or a a magnifier.


rete (-tia) L. = a net (-work); a snare.


rete Malpighii L. " ; the stratum germinativum of epidermis, called rete because of all the criss-crossing tonofilaments which it contains; cf. Malpighi.


rete mirabile L. " + L. = marvellous; sudden division of a vessel into a large number of capillaries which then reunite to a single vessel, as in a renal glomerulus, or swim bladder of some fish. Galen, dissecting animals, also thought it erroneously to be present around the internal carotid of man.


rete peg downward projection of stratum germinativum, which appears peg-like in 2-dimensions, but is really part of a ridge.


rete testis network of spaces in the mediastinum testis.


reticular adj. L. reticula = a little net; of a type of extracellular fibres that form a network and can be impregnated with silver salts; of a type of connective tissue with a network of many fine branching reticular fibres; thickest and strongest layer of dermis with many dense irregular collagen fibres.


reticulata (or reticularis) adj. L. " ; e.g., zona reticulata (reticularis) = deepest zone of adrenal cortex where cells are arranged in an irregular network.


reticulocyte L. " + kytos = hollow vessel; young red blood cell with network of basophilic protein in an acidophilic cytoplasm


reticulum L. reticula = a little net; cf. stellate.


retina from L. rete = a net, based on an inappropriate translation of Galen where G. amphiblestron = 1. that which surrounds the vitreous; 2. a fisherman's net; the light-sensitive coat of eye (not like a net!).


Retzius, Magnus Gustav. 1842-1919 Stockholm anatomist; lines of R. = concentric brown lines in tooth enamel.


ribosome ribose + G. soma = body; small cytoplasmic particle containing ribonucleoprotein (G. Palade).


rima L. = a cleft, fissure; rima glottidis = gap between vocal cords; rima palpebrarum = gap between eyelids (later, margins of eyelids).


Riolan, Jean, the son. ?1577,1580-1657 Paris anatomist, botanist & pharmacologist; R.'s muscle = 1. ciliary muscle (palpebral part of orbicularis oculi), 2. cremaster muscle.


Robin, Charles Philippe. 1821-1885 Paris histologist; described osteoclast; also cf. Virchow-Robin spaces = perivascular spaces around arterioles and arteries of central nervous system.


rod terminal part of the dendrite of a photoreceptor (sensory neuron) in the retina, responsible for perception of grey tones at low light intensities.


Rolando, Luigi. 1773-1831 Turin anatomist; fissure of R. = central sulcus of cerebral hemisphere (named eponymously by François Leuret after Rolando had shown it to him, 1839-1857); substantia gelatinosa of spinal cord.


Romanowsky, Dimitri L. 1861-1921 Russian physician; R.'s stain = a stain for parasites and cells of a blood film.


Rosenmüller, Johann Christian. 1771-1820 Leipzig anatomist & surgeon; organ of R. = epoöphoron; pharyngeal recess.


rouleaux F. = rolls (of erythrocytes).


Ruffini, Angelo. 1874-1929 Italian anatomist; R.'s nerve endings or bodies or corpuscles = varicose sensory nerve endings surrounded by a fibrous capsule found deep in connective tissues (1898).


ruga (-ae) L. = a fold or wrinkle, e.g., in stomach, in vagina.


Ruysch, Frederick. 1638-1731 Amsterdam anatomist; master of the preparation of injected specimens; described bronchial blood vessels, lymph valves; established a suberb anatomical museum, which was purchased by Peter the Great, but was destroyed en route to St. Petersburg when the sailors drank the alcohol used as a fixitive and preserving fluid.