Glossary of Histological & Micro-anatomical Terms
from the Department of Anatomy, University of New South Wales, Sidney, Australia.

 
 

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Ebner, Victor (Ritter von Rosenstein). 1842-1925 Innsbruck & Vienna histologist; E.'s glands = serous lingual glands; E.'s lines = fibrils in dentine and cementum of teeth; E.'s reticulum = network of cells in seminiferous tubules.

 

eccentric G. ek = out(side) + kentron = centre.

 

eccrine G. " + krinein = to separate; of sweat secretion, or of sweat glands.

 

ectoderm G. ek = outside + derma = skin; outer cell layer of embryo giving rise to CNS, skin, glands, etc.

 

ectopic G. ek = out + topos = placed; displaced; in an abnormal position; opposite to entopic.

 

ectoplasm G ektos = outside + plasma = a thing formed; outermost layer of cytoplasm.

 

Edinger, Ludwig. 1855-1918 Franfurt-am-Main anatomist & neurologist; skilled violinist; bequeathed his own brain for study; nucleus of Edinger-Westphal = oculomotor nucleus (1885); cf. Westphal.

 

efferent L. ex = away + ferre = to carry; centrifugal; e.g., motor nerves are efferent with respect to central nervous system; efferent arteriole of renal glomerulus; opposite to afferent, q.v.

 

effete worn out.

 

Ehrlich, Paul. 1854-1915 German pathologist & bacteriologist; named mast cells, q.v.; E.'s haematoxylin.

 

elastin G. elastikos = impulsive (as in elastic recoil); protein component of yellow fibres of elastic tissue.

 

electron-dense appearing dark in electron microscope; scatters electrons.

 

electron-lucent appearing light in electron microscope; transmits electrons; opposite to electron-dense.

 

eleidin G. elaia = oil; acidophilic substance in oily granules in cells of stratum lucidum of epidermis.

 

embolus G. embolos = wedge, something inserted; something blocking the lumen of a blood vessel.

 

embryo G. embryon = fruit of womb before birth, from bryein = to grow, swell out.

 

emphysema G. emphysan = to inflate; pathological distension of tissues by gas.

 

en bloc F. = in the block; of dyeing tissues in the block before sectioning the block in a microtome.

 

en face F. = face on; e.g. an aerial view of a surface.

 

enamel OF. esmail = enamel, from L. smatto = I smelt; hard prismatic white substance covering crown of tooth, like the enamel fused to surface of objects.

 

enarthrosis G. en = in + arthron = a joint; a ball-and-socket joint.

 

encephalon G. enkephalos = brain, from en = in + kephalos = head.

 

end artery a small artery that ends in branches which do not have sufficient anastomoses other arteries to keep the organ alive if the end artery is occluded, e.g., artery to the vermiform appendix (Cohnheim, c. 1860).

 

end-bulb the sensory corpuscle at the peripheral end of a sensory nerve, e.g., end-bulb of Krause.

 

endo- or ento- G. endon = within.

 

endocardium G. " + kardia = heart; the tunica intima of the heart.

 

endochondral G. " + chondros = cartilage; of ossification taking place in a cartilage model.

 

endocrine G. " + krinein = to separate; formation of internal secretions (= hormones) with release into blood or lymph stream.

 

endoderm or entoderm G. " + derma = skin; inner cell layer of embryo giving rise to digestive system, glands, liver, part of urinary system, etc; also called entoderm.

 

endolymph G. " + L. lympha = clear fluid, water; fluid inside the membranous labyrinth of the inner ear.

 

endometrium G. " + metra = womb; mucosal lining of uterus.

 

endomysium G. " + mys = muscle; fine connective tissue supporting single muscle cells within a muscle fascicle.

 

endoneurium G. " + neuron = sinew (nerve); delicate connective tissue supporting individual nerve fibres within a peripheral nerve fascicle.

 

endoplasm G. " + plasma = a thing formed; central, more fluid part of cytoplasm.

 

endoplasmic reticulum G. " + plasma = a thing formed + reticulum = a small net (-work), dimutive of L. rete, q.v.; a connecting network of membranous channels and sacs in cytoplasm; of two types: rough e.r. with many ribosomes on surface, and smooth e.r., without ribosomes; cf. ergastoplasm.

 

endosteum G. " + osteon = bone; vascular membrane and osteoblasts lining medullary cavity of a bone.

 

endotendineum G " L. tendo = sinew; connective tissue within a sinew (also endotenon).

 

endothelium G. " + thele = nipple; the special name for epithelium (q.v.) lining blood and lymph vessels.

 

enteroendocrine G. enteron = intestine + endon = within + krinein = to separate.

 

entoderm G. entos = within + derma = skin; see endoderm.

 

enzyme G. en = in + zyme = leaven (an early use of biotechnology!).

 

Eosin G. eos = dawn, rose-coloured; an acidic dye staining the basic cytoplasmic proteins pink.

 

eosinophil G. " + philein = to love; a type of blood cell with distinct cytoplasmic granules which stain pink with eosin.

 

eosinophilic having an affinity for eosin dye.

 

ependyma G. epi = upon + endyma = a garment, an upper garment, a wrap; a vest or singlet, hence an inner garment; cellular layer lining cerebral ventricles and central canal of spinal cord.

 

epi- G. = upon, on.

 

epicardium G. " + kardia = heart; outer layer of heart, including connective tissue (i.e., its tunica adventitia) and mesothelium of the serous visceral pericardium.

 

epidermis G. " + derma = skin; superficial layer of skin.

 

epididymis (-dymides) G. " + didymos = twofold, double, testis; hence an organ on the posterosuperior aspect of the duplicated organ, the testis, with a duct through which spermatozoa pass; cf. ductus epididymidis.

 

epidural space space external to the dura mater in the spinal cord.

 

epiglottis G. " + glottis = throat, larynx; leaf-shaped structure of the upper part of larynx at root of tongue.

 

epimysium G. " + mys = muscle; loose connective tissue investing several muscle fascicles = muscle fascia, q.v.

 

epineurium G. " + neuron = sinew; loose connective tissue investing several nerve fascicles.

 

epiphysis (-ses) G. epi = upon + physis = a growth; extremities of long bones, covering the actual sites of growth (= metaphysis); also epiphysis cerebri = pineal gland.

 

epiploic G. epiploon = a net; relating to greater omentum, resembling a net with adipose tissue deposits (Galen, c. 180 AD).

 

epithelioid cells G. -oeides = like; cells that appear like those of an epithelium but are not, e.g., lymphocytes around the germinal centre of an active lymphatic follicle; juxtaglomerular cells of an afferent arteriole in the kidney.

 

epithelium (-ia) G. epi = upon + thele = nipple, ridge of the lip; cells that cover the ridges of the lip (Ruysch, c. 1700); cells covering organs and structures, or lining spaces, tubes (Henle, c. 1870); many epithelia separate the inside the body from the outside world and its inward extensions.

 

eponychium G. " + onyx = nail; horny structure (i.e., stratum corneum) of skin fold covering root of a nail; cuticle of a nail.

 

epoöphoron G. " + oöphoron = ovary; minute tubules in mesosalpinx derived from upper part of embryonic mesonephros.

 

ergastoplasm G. ergon = work + plasma = a thing formed; cytoplasmic ribonucleic acid as a site of protein synthesis; synonym for rough endoplasmic reticulum.

 

erythroblast G. erythros = red + blastos = germ; early stage in development of an erythrocyte.

 

erythrocyte G. " + kytos = hollow vessel; red blood cell (without a nucleus).

 

erythropoiesis G. " + poiesis = making; process of erythrocyte production in bone marrow, liver, etc.

 

euchromatin G. eus = good + chroma = colour; chromatin rich in nucleic acid.

 

Eustachio, Bartolomeo. ?1513,1524-1574 Rome anatomist & physician to Pope; studied teeth; described thoracic duct (vena alba magna), cochlea, larynx; Eustachian tube = the cartilaginous part of auditory tube (1562).

 

evagination L. evaginare = to unsheath; protrusion of an organ or a surface.

 

exocrine G. exo = outside + krinein = to separate; of glands retaining connection with epithelial surface (opposite to endocrine).

 

extrafusal L. extra = out + fusus = a spindle; of normal skeletal muscle fibres other than the intrafusal (q.v.) fibres of the muscle spindle.

 

extravasation L. extra = out + vas = vessel; leakage, e.g., of urine from urinary tract.

 

exudate L. ex = out + sudare = to sweat.

 

Fabricius of Aquapendente, Hieronymus. ?1533,1537-1619 Studied under Fallopius; Padua anatomist; taught William Harvey; described valves in veins; bursa of F. = peritoneal blind pouch near anus in birds, producing lymphocytes.

 

facet F. facette = a face.

 

Fallopius, Gabriele. 1523-1563 Ferrara, Pisa & Padua anatomist & botanist; described accurately the inner ear, ethmoid bone, lacrimal duct, vagina, placenta; disproved earlier notion that ovarian ligaments conducted ovum to uterus; Fallopian tube = uterine tube (1561).

 

fascia (-ae) L. = a band, bandage; fibrous membrane covering and supporting muscles, cf. epimysium; hypodermis.

 

fascia adherens L. " + adhaerere = to stick to; most prominent component of the intercalated disc joining two cardiac muscle muscle cells; resembles zonula adherens of epithelium.

 

fascicle L. fasciculus = a little bundle, dim L. facis (fasces was a symbolic bundle of rod with an axe in the middle); e.g., a bundle of nerve fibres, of muscle fibres.

 

fasciculata adj. L. " ; e.g., zona fasciculata = middle zone in adrenal cortex where cells are arranged in columns.

 

Fast green a synthetic dye resistant to fading used in histology & cytology.

 

fenestrated adj. L. fenestra = window; 1. of an aperture in a cell membrane (e.g., in a capillary endothelial cell) often closed by a membrane; 2. of an aperture in an elastic sheet in tunica media of an artery.

 

Ferrein, Antoine. 1692-1769 Paris surgeon & physician. F.'s processes = medullary rays of kidney.

 

fibre L. fibra = fibre (Vesalius, c. 1550); original meaning was a lobe, e.g., of lung, liver, or bowels examined for prophecies.

 

fibril L. fibrilla = a small fibre (from L. fibra = fibre); subunit of a fibre, i.e., many fibrils bundle together to form a fibre; cf. microfibril.

 

fibroblast L. fibra = fibre + G. blastos = germ; young flat, elongated cell forming collagen.

 

fibrocartilage L. " + cartilago = gristle; a type of cartilage with many collagen fibres.

 

fibrocyte L. " + kytos = a vessel; mature form of the fibroblast, especially in tendon.

 

field of view the circular field seen when looking into an optical device.

 

filiform L. filum = a thread + forma = form; hair-like, of thread of keratin emerging from the apex of a filiform lingual papilla.

 

fimbria L. = a fringe; e.g., fimbria at ovarian end of uterine tube; fimbria of 3rd ventricle of brain.

 

flavum L. flavus = yellow (often due to presence of large amount of elastic tissue); ligamentum flavum of vertebral column.

 

Flechsig, Paul Emil. 1847-1929 Leipzig psychiatrist; named pyramidal tract; nucleus of F. = superior vestibular nucelus; fasciculus of F. = fasciculus lateralis proprius of spinal cord; F.'s law of myelination.

 

flocculus L. = a little tuft, dim. L. floccus; small lobe beneath each cerebellar hemisphere.

 

folium (-ia) L. = a leaf; 1. folds of cerebellar cortex; 2. leaf-like foliate papillae of tongue.

 

follicle L. folliculus = little bag (dim. of L. follis).

 

Fontana, Abbada Felice ?1720,1730-1805. Pisa philosopher; Director, Florence Museum of Natural Science; F.'s spirals = spiral pattern of nerves in a peripheral nerve fascicle; spaces of F. = spaces in the pectinate ligament of the iridocorneal angle of the iris through which the aqueous humour flows into the scleral venous canal (of Schlemm).

 

formalin fixative; aqueous solution of 37% formaldehyde, possibly with trace amounts of methanol.

 

fornix (-ices) L. = a cellar, a vault, the arch of a vault, a prostitute's cellar or brothel (hence fornication); conjuctival fornix = recess where palpebral conjunctiva joins to bulbar conjunctiva; vaginal fornices = vaults surrounding intravaginal part of cervix; fornix of the brain = arched bundle of fibres.

 

fossa (-ae) L. = a trench or ditch; axillary fossa = armpit; fossa ovalis = opening in thigh through which saphenous vein passes; fossa ovalis cordis = remnant of embryonic foramen ovale in heart; navicular fossa, q.v.

 

fourchette F. = fork; fold of mucous membrane at junction of posterior parts of labia majora.

 

fovea L. = a pit or depression.

 

fovea centralis L. = central depression; pit in retina which is site of maximum acuity.

 

foveola (-ae) L. = a little pit (dim. of L. fovea).

 

foveola gastrica L. = a little pit of the stomach; a gastric pit = a groove into which several gastric glands drain.

 

frenulum L.= a small bridle, dim L. frenum; frenulum linguae (when short - "tongue-tied").

 

fundus L. = bottom, base (as in fundamental); refers to region of organ (e.g., stomach, uterus, eye), gland (e.g., gastric glands).

 

fungiform L. fungus = mushroom + forma = a shape; of lingual papillae.

 

funiculus (-i) L. = a little cord (dim. L. funis = cord); a cordlike structure composed of longitudinally oriented fibres, vessels, etc., e.g., funiculi of white matter of spinal cord; funiculus spermaticus = spermatic cord; funiculus umbilicus = umbilical cord

 

fusiform L. fusus = spindle + forma = shape; see extrafusal/intrafusal.

 

Galen, Claudius? Clarissmus. ?129,130-200,201 AD Rome physician to Marcus Aurelius; famous early anatomist (however many statements based on animal dissections); great cerebral vein of Galen; collected medical works of Galen.

 

Gallocyanin a purple synthetic basic dye used to staining nuclei acids.

 

gamete G. = a wife, from gamein = to marry; a mature male germ cell (spermatozoon) or female germ cell (ovum); their union produces a zygote, q.v.

 

ganglion (-a, -ions) G. = knot, swelling; an accumulation of nerve cell somas outside the central nervous system; also applied to cells forming optic nerve axons within the central nervous system; also small synovial swelling under skin.

 

gap junction intercellular junction for communication between cells (see nexus).

 

Gärtner, Hermann Treschow. 1785-1827 Copenhagen physician & anatomist; G.'s duct = longitudinal duct of epoöphoron (q.v) = remains of mesonephric duct.

 

Gasser, Johann Ludwig. 1757-1765 Vienna anatomist; Gasserian ganglion = semilunar ganglion of trigeminal nerve (actually described by a student of Gasser, Raimund Hirsch, 1765).

 

gastric adj. L. gastricus, from G. gaster = stomach, belly; relating to the stomach.

 

gastric pit foveola gastrica, q.v.

 

gelatine L. = protein derived by hydrolysis (boiling) of collagen present in skin, bone and joints.

 

gemmules L. gemmula = a little bud; minute processes on dendrites of a neuron.

 

genital adj. L. genitalis = of birth.

 

Gennari, Francesco 1750-? Parma anatomist; stria of G. = the distinct outer stria of Baillarger (q.v.) in the visual part of the cerebral cortex (1782); hence striate cortex, q.v.

 

Gerlach, Joseph von. 1820-1896 Erlangen anatomist; invented method of injecting cadavers with carmine & gelatine; G.'s tonsil = tubal tonsil; G.'s valve = a fold of mucosa sometimes seen at entrance to vermiform appendix; G.'s valvulae = trabecular meshwork of pectinate ligament.

 

germinal L. germen = an offshoot; germinal epithelium of ovary (but not a source of germ cells!).

 

germinativum L. germinare = to sprout; deepest layer or stratum of epidermis = Malpighian layer.

 

Gerota, Dumitru. 1867-1939 Roumanian anatomist; G.'s fascia = perirenal fascia.

 

gingiva (-ae) L. = the gum.

 

Giraldès, Joachim Albin Cardozo Cazado. 1808-1875 Paris surgeon from Portugal; died of a wound acquired during an autopsy; organ of G. (1859) = paradidymis, q.v.

 

glabella L. glaber = smooth; space between eyebrows, often devoid of hair.

 

glabrous adj. L. glaber = smooth; of non-hairy skin.

 

gland L. glandula, dim of L. glans = an acorn, a pellet; term used to describe mesenteric lymph nodes (Herophilus, c. 300 BC).

 

glia G. gloia = glue; neuroglia is the non-nervous supporting tissue of central nervous system; gliosis = hyperplasia of astrocytes, q.v.

 

Glisson, Francis. 1597-1677 Cambridge classicist & physician; described bile duct and its sphincter (cf. Oddi); G.'s capsule = fibrous capsule of liver.

 

glomerulosa adj. L. = like a little ball; e.g., zona glomerulosa = superficial zone in adrenal cortex where cells are arranged in small clusters.

 

glomerulus (-i) L. = a little ball, dim. of L. glomus (from L. glomerare = to roll up, as in conglomerate); renal glomerulus = a cluster of capillaries in kidney cortex = Malpighian corpuscles; olfactory glomerulus = a ball of nerve cells and fibres in the olfactory bulb, where primary olfactory fibres synapse with mitral cells, q.v.

 

glomus (-mera) L. = a ball; cluster or conglomeration of small arteries or arterioles and nerve fibres, e.g., carotid glomus, at bifurcation of common carotid; choroidal glomus, at site where choroid plexus enters inferior horn of lateral ventricle; coccygeal glomus (or body) = glomus coccyxgeum, associated with median sacral artery at coccyx, cf. glands of Luschka.

 

glottis G. = larynx; now the space between the vocal cords.

 

glycan G. glykos = sweet.

 

glycocalyx G. " + kalyx = cup; layer like a husk rich in carbohydrates outside cell plasma membrane.

 

glycogen G. " + gennan = to produce; a polysaccharide ("animal starch") in liver, muscle, etc. yielding glucose on .hydrolysis.

 

glycosaminoglycan (abb. GAG) chemical constituent of glycocalyx.

 

Goethe, Johann Wolfgang von. 1749-1832 German poet & scientist; G.'s bone = premaxilla; G.'s theory of vertebral origin of skull; G.'s theory of colour.

 

Golgi, Camillo. 1844-1926. Italian histologist; shared Nobel prize in 1906 with Cajal, q.v.; Golgi apparatus (or G. complex) = an organelle consisting of a system of cytoplasmic membranes; G. technique = a histological staining technique for impregnation of single neurons (cf. Cajal); G. cells of nervous system; G. corpuscle = a sensory receptor in tendon, tendon; axon collaterals of G; Golgi-Mazzoni corpuscles = corpuscular nerve endings.

 

Goll, Friedrich. 1829-1903 Zurich pharmacologist; column of G. = funiculus gracilis of spinal cord (1860).

 

Gomori, George. American histochemist 1904- ; trichrome and histochemical stains.

 

gomphosis G. gomphos = wedge-shaped nail or bolt used in ship-building; a peg-in-socket joint (Galen, c. 180 AD); junction of tooth in alveolar socket.

 

gonad G. gone = seed; organs containing germ cells, i.e., ovary and testis.

 

Gowers, William Richard (Sir). 1845-1915 London physician & neurologist; tract of G. = superficial anterolateral fasciculus of spinal cord = anterolateral spinocerebellar tract.

 

Graaf, Regnier de. 1641-1673 Delft physician, anatomist; contemporary of Swammerdam & Leewenhoek; described corpus luteum; Graafian follicle = a mature ovarian follicle (1672).

 

granulosa L. granulum = little grain; cells around ovarian oocyte.

 

granulosum L. " ; referring to granule-containing cells in epidermis.

 

gray matter parts of central nervous system where there are relatively fewer myelinated fibres; central part of spinal cord; cortex of cerebrum and cerebellum; cf. white matter.

 

ground substance colloidal material, with variable viscosity, of the intercellular spaces of connective tissue; usually homogeneous and scarcely stainable.

 

Guérin, Alphonase F.M. 1816-1895 French surgeon; G.'s valve = fold of mucous membrane in navicular fossa of urethra.

 

gyrus G. gyros = circle, arc; one of the coils or convolutions of cerebral cortex, separated by sulci or fissures.

 

H-band abb. of Hell-band Ge. hell = light + band; also Henle's band; light band within A-band of the myofibril.

 

haematocrit G. haima = blood + krinein = to separate; the proportion by volume of erythrocytes (packed by centrifugation of a thin tube containing blood).

 

Haematoxylin a basic dye from a South American tree; its oxidation product haematein is used with mordants for histological staining of nucleic acids.

 

haemopoiesis G. haima = blood + poiein = to make; production of the cellular elements of blood, in bone marrow, etc. (also haematopoiesis).

 

Haller, Albrecht von. 1708-1777 Göttingen anatomist, surgeon & botanist; eminent scientist & poet; dissected over 400 cadavers and wrote extensive anatomical bibliography; ductulus aberrans of H. = a diverticulum of the canal of the ductus epididymidis; H.'s layer = vascular lamina of the choroid, q.v.; H.'s rete = rete testis.

 

haploid G. haplos = plain, simple; having the simplest (i.e., single) set of self-contained chromosomes in germ cells; cf. diploid.

 

Hartmann, Robert. 1831-1893 German anatomist; H.'s pouch = outpouching of gall bladder near its junction with cystic duct.

 

Hassall, Arthur Hill. 1817-1894 London chemist, botanist & physician; H.'s corpuscles = concentrically laminated corpuscles of thymus (1846).

 

haustrum (-a) L. haurire = to draw water in a bucket; sacculated pouches of colon.

 

Havers, Clopton. ?1655,1657-1702 London physician & anatomist; Haversian canals = minute vascular canals in compact bone (1691); Haversian glands = pads, folds or fringes containing fat in a synovial membrane (1691); Haversian lamellae = bony lamellae in an osteon (1691); Haversian system = an osteon (1691), q.v.; cf. Leeuwenhoek's canals.

 

Heidenhain, Martin. 1864-1949 Tübingen pathologist & histologist; H.'s azan = a histological dye; H.'s crescent cells = serous demilunes.

 

Heidenhain, Rudolph Peter Heinrich. 1834-1897 Breslau physiologist & histologist; described gastric parietal cells.

 

Heister, Lorenz. 1638-1758 Altdorf anatomist, surgeon & botanist; Helmstädt surgeon & botanist; H.'s valve = spiral folds of cystic duct.

 

helicine adj. G. helix = coil, snail; e.g, helicine arteries of ovarian medulla, penis, etc.

 

helicotrema G. " + trema = a hole; union of scala tympani and scala vestibuli at apex of cochlear canal.

 

hemidesmosome G. hemi = half + desmosome; found in cells of basal stratum of stratified epithelia.

 

Henle, Freidrich Gustav Jacob. 1809-1885 Zurich, Heidelberg & Göttingen anatomist; loop of H. = ansa nephronis (q.v.) of renal tubule (1866); endoneurium; H.'s layer = outer layer of cells of inner root sheath of hair follicle.

 

Hensen, Victor. 1835-1924 Kiel physiologist & embryologist; H.'s duct = ductus reuniens of membranous labyrinth; H.'s knot (or node) of embryonic disc; H.'s line = light band in middle of dark band of sarcomere = H-band, q.v.

 

hepatocyte G. hepar = liver + kytos = hollow vessel; liver parenchymal cell.

 

Herring, Percy T. 1872-1967 St. Andrews physiologist; H. bodies = axonal varicosities containing granules of neurophysins (q.v.) in pars nervosa of hypophysis.

 

heterochromatin G. heteros = other + chromatin; other than euchromatin.

 

Highmore, Nathaniel. 1613-1685 Dorsetshire physician; body of Highmore = mediastinum testis (1651).

 

hilum or hilus (-a) L. = a trifle; depression in a seed; a depression at vascular entrance/exit of a gland or organ.

 

hircus (-ci) L. = a he-goat; hair of arm-pits which had a goat-like smell; tragus of pinna with its tuft of goat's-beard-like hairs.

 

His, Wilhelm (the elder). 1831-1904 Basle, Leipzig anatomist; copula of H. = bond joining ventral ends of third pharyngeal arches in embryo (1880).

 

His, Wilhelm (the younger). 1863-1934 Leipzig, Basle, Göttingen & Berlin anatomist; bundle of H. = atrioventricular bundle of conducting tissue in heart (1893).

 

histiocyte a macrophage, q.v.

 

histochemistry G. histos = web, tissue + chemeia = chemistry; application of specific chemical reagents to a histological section to reveal the location (topography) of natural substances within the various tissues of the section; cf. cytochemistry.

 

histology G. histos = web, woven material, sail of a ship + logos = knowledge, study; microscopic anatomy, as opposed to macroscopic anatomy.

 

Hoboken, Nicolas van. 1632-1678 Harderwyck anatomist; valves of H. = internal valve-like folds of umbilical vessels.

 

holocrine G. holos = entire + krinein = to separate; a type of secretion where entire cell forms the secretory product, as in sebaceous glands.

 

Hooke, Robert. 1635-1703 English scientist; skilled in use of compound microscope; described cells in cork.

 

Howship John, 1781-1841, English surgeon; H.'s lacunae or foveolae= small depressions in bone where resporption of bone by osteoclasts takes place.

 

humour L. umor = a fluid; aqueous humour and vitreous humour of the eye.

 

Huxley, Thomas Henry. 1825-1895 English anatomist & naturalist; H.'s layer = the layer of cells lying inside Henle's layer (q.v.) in root-sheath of hair follicle,

 

hyaline adj. G. hyalos = glassy, translucent, crystalline; hyaline cartilage with its glassy appearance.

 

hyaloid adj. G. " + -oeides = form of.

 

hyaluronidase testicular enzyme, present in semen, depolymerises hyaluronic acid of ground substance.

 

hydatid G. hydatis = watery vesicle; a cyst; e.g., appendix testis is the hydatid of Morgagni.

 

hydroxyapatite crystalline, inorganic component of matrix of mature bone.

 

hymen G. = a membrane, also Greek god of marriage; membrane partially covering entrance to vagina (Vesalius, c. 1550).

 

hyperplasia G. hyper = above, an excess of + plassein = to form; growth of organ due to increase in cell number.

 

hypertrophy G. " + trophe = nourishment; growth of organ or tissue (e.g., muscle) due to increase in cell size.

 

hypodermis G. hypo = under, a lack of + dermis; subcutaneous connective tissue = superficial fascia.

 

hyponychium G. " + onyx = nail; thickened stratum corneum under the free end of a nail.

 

hypophysis G. = an undergrowth; pituitary gland under the brain; cf. epiphysis.

 

hypoplasia G. " + plassein = to form; reduction in tissue or organ size.

 

hypothalamus G. " + thalamus; below the thalamus, q.v.

 

 

 
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