Copy of `Dorland's Medical Dictionary`

The wordlist doesn't exist anymore, or, the website doesn't exist anymore. On this page you can find a copy of the original information. The information may have been taken offline because it is outdated.

Dorland's Medical Dictionary Category: Health and Medicine > Medical Dictionary Date & country: 31/12/2010, USA Words: 39128

hyaloplasm
(hi´ә-lo-plaz″әm) the more fluid, finely granular substance of the cytoplasm of cells.

hyaloserositis
(hi″ә-lo-se″ro-si´tis) inflammation of serous membranes marked by conversion of the serous exudate into a pearly coating of the affected organ.

hyalosis
(hi″ә-lo´sis) degenerative changes in the vitreous humor. asteroid hyalosis the presence of spherical or star-shaped opacities in the vitreous humor.

hyaluronate
(hi″ә-ldbobr´ro-nāt) a salt, anion, or ester of hyaluronic acid. The sodium salt and a derivative of it are used as analgesics in treatment of osteoarthritis of the knee, administered by intra-articular injection.

hyaluronic acid
(hi″ә-ldbobr-ron´ik) a glycosaminoglycan found in lubricating proteoglycans of synovial fluid, vitreous humor, cartilage, blood vessels, skin, and the umbilical cord.

hyaluronidase
(hi″ә-ldbobr-ron´ĭ-dās) an enzyme that catalyzes the hydrolysis of hyaluronic acid, the “cement material” of connective tissues; it is found in human testes, as well as in leeches, snake venom, and spider venom, and is produced by various pathogenic bacteria, enabling them to spread thr...

hybrid
(hi´brid) an offspring of genetically different parents. something of mixed origin or composition.

hybridization
(hi″brid-ĭ-za´shәn) the act or process of producing hybrids. nucleic acid hybridization. fluorescence in situ hybridization(FISH) in situ hybridization in which DNA probes are labeled with fluorescent tags and hybridized to metaphase chromo...

hybridoma
(hi″brid-o´mә) a somatic cell hybrid formed by fusion of normal lymphocytes and tumor (lymphoma) cells. B cell hybridomas are the most useful source of monoclonal antibodies; the hybridoma cells are able to produce antibody like the normal parent and to proliferate indefinitely in culture like the pare...

hyclate
(hi´klāt) USAN contraction for monohydrochloride hemiethanolate hemihydrate.

hydantoin
(hi-dan´to-in) a crystalline base derivable from allantoin. any of a group of anticonvulsants containing such a ring structure, including phenytoin and ethotoin.

hydatid
(hi´dә-tid) hydatid cyst. any cystlike structure. hydatid of Morgagni a cystlike remnant of the müllerian duct on the upper end of the testis. one of the small pedunculated structures attached to the uterine tubes near their fimbriated end; remnants of...

hydatid cyst
the larval stage of the tapeworms Echinococcus granulosis and E. multilocularis; each one contains daughter cysts that have many scoleces (mouths). See also hydatid disease. Called also echinococcal cyst and hydatid.

hydatid disease
an infection, usually of the liver, caused by larval forms (hydatid cysts) of tapeworms of the genus Echinococcus, and characterized by the development of expanding cysts. In the infection caused by E. granulosus, single or multiple cysts that are unilocular in character are formed, and in that caused by E. multilocularis, the host's...

hydatid tapeworm
Echinococcus granulosus.

hydatidiform
(hi″dә-tid´ĭ-form) resembling a hydatid; see also hydatidiform mole.

hydatidosis
(hi″dә-tĭ-do´sis) hydatid disease.

hydatidostomy
(hi″dә-tĭ-dos´tә-me) incision and drainage of a hydatid cyst.

Hydergine
(hi´dәr-jēn) trademark for preparations of ergoloid mesylates, ergot alkaloids used to combat mild to moderate dementia in the elderly.

hydragogue
(hi´drә-gog) increasing the fluid content of the feces. a cathartic that has this effect.

hydralazine
(hy-dral´ә-zēn) an antihypertensive agent and vasodilator, administered orally, intramuscularly, or intravenously as the hydrochloride salt in treatment of peripheral vascular disease, essential and early malignant hypertension, thrombophlebitis, and other conditions in which dilation of blood vessels of the ...

hydramnios
(hi-dram´ne-os) polyhydramnios.

hydranencephaly
(hi″dran-әn-sef´ә-le) absence of the cerebral hemispheres, with their normal site being occupied by cerebrospinal fluid.

hydrarthrosis
(hi″drahr-thro´sis) an accumulation of watery fluid in the cavity of a joint. adj., hydrarthro´dial., adj.

hydratase
(hi´drә-tās) an enzyme that catalyzes the hydration-dehydration of CsbondO linkages.

hydrate
(hi´drāt) a compound of water with a radical. a salt or other compound that contains water of crystallization.

hydration
(hi-dra´shәn) the absorption of or combination with water.

hydraulics
(hi-draw´liks) the science dealing with the mechanics of liquids.

hydrazine
(hi´drә-zēn) a gaseous diamine, H4N2, or any of its substitution derivatives.

Hydrea
(hi-dre´ә) trademark for a preparation of hydroxyurea, an antineoplastic agent.

hydremia
(hi-dre´me-ә) excess of water in the blood, so that it has a low osmolality; see also hypo-osmolality.

hydrencephalocele
(hi″dren-sef´ә-lo-sēl″) hydroencephalocele.

hydro-lyase
(hi″dro-li´ās) an enzyme that catalyzes the removal of a hydrogen atom and a hydroxyl group from the substrate molecule as water and the formation of a double bond.

hydroa
(hi-dro´ә) a vesicular or bullous eruption. hydroa vacciniforme a vesicular and bullous eruption on sun-exposed areas of the skin, sometimes preceded by pruritus and a burning sensation; it occurs most often in children and tends to recur each summer.

hydroalcoholic
(hi″dro-al″kә-hol´ik) pertaining to or containing both water and alcohol.

hydroappendix
(hi″dro-ә-pen´diks) distention of the vermiform appendix with watery fluid.

hydrocalycosis
(hi″dro-ka″lĭ-ko´sis) a usually asymptomatic cystic dilatation of a major renal calix, lined by transitional epithelium, and due to obstruction of the infundibulum.

hydrocarbon
(hi´dro-kahr″bәn) an organic compound that contains carbon and hydrogen only. alicyclic hydrocarbon one that has cyclic structure and aliphatic properties. aliphatic hydrocarbon one in which no carbon atoms are joined to form a ring. ...

hydrocele
(hi´dro-sēl) a circumscribed collection of fluid; especially, a painless swelling of the scrotum caused by fluid in the tunica vaginalis testis, the outermost covering of the testes. It can be removed by withdrawing the fluid by tapping through the outer layer of tissue, or by cutting away the outer layer of tissue...

hydrocelectomy
(hi″dro-se-lek´tә-me) excision of a hydrocele.

hydrocephalocele
(hi″dro-sef´ә-lo-sēl″) hydroencephalocele.

hydrocephaloid
(hi″dro-sef´ә-loid) resembling hydrocephalus.

hydrocephaloid disease
a condition resembling hydrocephalus, but with depressed fontanels, following severe diarrhea.

hydrocephalus
(hi″dro-sef´ә-lәs) enlargement of the skull because of abnormal accumulation of cerebrospinal fluid within the ventricular system of the brain. Although it occurs occasionally in adults, it is usually seen in young children associated with a congenital defect, especially a neural tube defect. The two c...

hydrocephaly
(hi″dro-sef´ә-le) hydrocephalus.

hydrochloric acid
(hi″dro-klor´ik) HCl, a normal constituent of gastric juice in humans and other animals. The absence of free hydrochloric acid in the stomach, called achlorhydria or gastric anacidity, may be found with chronic gastritis, gastric carcinoma, pernicious anemia, pellagra, and alcoholism.

hydrochloride
(hi″dro-klor´īd) an addition salt of hydrochloric acid with an organic base.

hydrochlorothiazide
(hi″dro-klor″o-thi´ә-zīd) a thiazide diuretic used as an antihypertensive agent and for treatment of edema.

hydrocholecystis
(hi″dro-ko″lә-sis´tis) distention of gallbladder with watery fluid.

hydrocholeresis
(hi″dro-ko″lә-re´sis) choleresis with excretion of watery bile (low in specific gravity, viscosity, and total solid content).

hydrocholeretic
(hi″dro-ko″lәr-et´ic) pertaining to or producing hydrocholeresis. an agent that so acts.

hydrocodone
(hi″dro-ko´dōn) a semisynthetic opioid analgesic similar to but more active than codeine; used as the bitartrate salt or polistirex complex as an oral analgesic and antitussive. Continued use may cause addiction.

hydrocolloid
(hi″dro-kol´oid) a colloid in which water is the dispersion medium; one type is used in dentistry as an impression material.

hydrocolpos
(hi″dro-kol´pos) collection of watery fluid in the vagina.

hydrocortisone
(hi″dro-kor´tĭ-sōn) the pharmaceutical term for cortisol, the principal glucocorticoid secreted by the adrenal gland; the base and its salts, including h. acetate, h. butyrate, h. cypionate, h. probutate, h. sodium phosphate, h. sodium succinate, and h. valerate, are used in replacement therapy for adrenocorti...

Hydrocortone
(hi″dro-kor´tōn) trademark for preparations of hydrocortisone, a corticosteroid.

hydrocyanic acid
(hi″dro-si-an´ik) hydrogen cyanide.

hydrocyst
(hi´dro-sist) a cyst with watery contents.

hydrocytosis
(hi″dro-si-to´sis) stomatocytosis.

HydroDIURIL
(hi″dro-di´u-ril) trademark for a preparation of hydrochlorothiazide, a diuretic and antihypertensive agent.

hydroencephalocele
(hi″dro-en-sef´ә-lo-sēl) hernial protrusion through a cleft in the skull of brain tissue containing fluid; called also hydrocephalocele and hydrencephalocele.

hydroflumethiazide
(hi″dro-floo″mә-thi´ә-zīd) a thiazide diuretic used as an antihypertensive agent and for treatment of edema.

hydrogel
(hi´dro-jel″) a gel that contains water.

hydrogen
(H) (hi´dro-jәn) a chemical element, atomic number 1, atomic weight 1.00797. It exists as the mass 1 isotope (protium, or light or ordinary hydrogen), mass 2 isotope (deuterium, heavy hydrogen), and mass 3 isotope (tritium). hydrogen cyanide an extremely...

hydrogen bond
a weak, primarily electrostatic, bond between a hydrogen atom bound to a highly electronegative element (such as oxygen or nitrogen) in a given molecule, or part of a molecule, and a second highly electronegative atom in another molecule or in a different part of the same molecule.

hydrogen breath test
(for deficiency of lactase or other hydrolases, or colonic overgrowth of bacteria) a known quantity of carbohydrate is administered and the subject's exhaled breaths are trapped and measured at timed intervals; patients unable to digest or absorb carbohydrates in the small intestine will have excess carbohydrates in the colon b...

hydrogen electrode
an electrode made by depositing platinum black on platinum and then allowing it to absorb hydrogen gas to saturation; used in determination of hydrogen ion concentration.

hydrogen ion concentration
the degree of concentration of hydrogen ions in a solution; it is inversely related to the pH of the solution and can be expressed by the equation [H+] = 10−pH.

hydrogen peroxide test
(for blood) a 20 per cent solution of hydrogen peroxide is added to the suspected fluid; if blood is present even in minute proportion, bubbles will rise, forming foam on the surface of the fluid.

hydrogen sulfide poisoning
poisoning by excessive exposure to hydrogen sulfide gas, seen primarily in those who work with petroleum or petrochemicals. The gas is a potent inhibitor of cytochrome-c oxidase and poisoning is characterized by metabolic acidosis and anoxia; severe cases may result in coma with death from respiratory paralysis.

hydrogenate
(hi´dro-jәn-at″) to cause to combine with hydrogen; to reduce with hydrogen.

hydrogymnastics
(hi″dro-jim-nas´tiks) therapeutic exercise performed in water.

hydrokinetic
(hi″dro-kĭ-net´ik) relating to movement of water or other fluid, as in a whirlpool bath.

hydrokinetics
(hi″dro-kĭ-net´iks) the science dealing with fluids in motion.

hydrolase
(hi´dro-lās) one of the six main classes of enzymes, comprising those that catalyze the hydrolysis of a compound.

hydrolysate
(hi-drol´ә-zāt) any compound produced by hydrolysis. protein hydrolysate any of various mixtures of amino acids that are prepared by splitting a protein with acid, alkali, or an enzyme and can be used as nutrient and fluid replenishers in special diets or for patients ...

hydrolysis
(hi-drol´ә-sis) pl. hydrol´yses the cleavage of a compound by the addition of water, the hydroxyl group being incorporated in one fragment and the hydrogen atom in the other. adj., hydrolyt´ic., adj.

hydroma
(hi-dro´mә) hygroma.

hydromeningitis
(hi″dro-men″in-ji´tis) meningitis with serous effusion.

hydromeningocele
(hi″dro-mә-ning´go-sēl) protrusion of the meninges through a defect in the skull or vertebral column, forming a fluid-containing sac.

hydrometer
(hi-drom´ә-tәr) an instrument for determining the specific gravity of a fluid.

hydrometra
(hi″dro-me´trә) collection of watery fluid in the uterus.

hydrometrocolpos
(hi″dro-me″tro-kol´pos) collection of watery fluid in the uterus and vagina.

hydrometry
(hi-drom´ә-tre) measurement of specific gravity with a hydrometer. adj., hydromet´ric., adj.

hydromicrocephaly
(hi″dro-mi″kro-sef´ә-le) smallness of the head with an abnormal amount of cerebrospinal fluid.

hydromorphone
(hi″dro-mor´fōn) a morphine alkaloid with effects similar to morphine but greater and of shorter duration; used as the hydrochloride salt as an analgesic, antitussive, and anesthesia adjunct, administered orally, subcutaneously, intramuscularly, intravenously, or rectally.

hydromphalus
(hi-drom´fә-lәs) a cystic accumulation of watery fluid at the umbilicus.

hydromyelia
(hi″dro-mi-e´le-ә) dilatation of the central canal of the spinal cord with an abnormal accumulation of fluid.

hydromyelomeningocele
(hi″dro-mi″ә-lo-mә-ning´go-sēl) a defect of the spine marked by protrusion of the membranes and tissue of the spinal cord, forming a fluid-filled sac.

hydromyoma
(hi″dro-mi-o´mә) a leiomyoma with cystic degeneration.

hydronephrosis
(hi″dro-nә-fro´sis) distention of the renal pelvis and calices with urine as a result of obstruction or atrophy of the urinary tract. Symptoms include recurrent pain in the kidney region, pus and blood in the urine, and fever if infection develops. If both kidneys are involved, there will be uremia as the fu...

hydronium
(hi-dro´ne-әm) the hydrated proton H3O+; it is the form in which the proton (hydrogen ion, H+) exists in aqueous solution, a combination of H+ and H2O.

hydropericarditis
(hi″dro-per″ĭ-kahr-di´tis) pericarditis with watery effusion.

hydropericardium
(hi″dro-per″ĭ-kahr´de-әm) an abnormal collection of fluid in the pericardial cavity.

hydroperitoneum
(hi″dro-per″ĭ-to-ne´әm) ascites.

hydrophilia
(hi-dro-fil´e-ә) the property of absorbing water; having a strong affinity for water.

hydrophilic
(hi″dro-fil´ik) readily absorbing moisture; hygroscopic; having strongly polar groups that readily interact with water.

hydrophilic contact lens
soft contact lens.

hydrophilous
(hi-drof´ĭ-lәs) hydrophilic.

hydrophobia
(hi″dro-fo´be-ә) irrational fear of water. choking, gagging, and fear on attempts to drink, a symptom of the paralytic phase of rabies. former term for rabies.