Medical Dictionary

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oliva, pl .olivae (o-li′va) [TA]
A smooth oval prominence of the ventrolateral surface of the medulla oblongata lateral to the pyramidal tract, corresponding to the inferior olivary nucleus. SYN: corpus olivare, inferior olive, olivary body, olivary eminence, olive (1) . [L.] o. inferior the o.. o. superior SYN: dorsal nucleus of trapezoid body.

olivary (ol′i-var-e)
1. Relating to the oliva. 2. Relating to or shaped like an olive.

olive (ol′iv)
1. SYN: oliva. 2. Common name for a tree of the genus Olea (family Oleaceae) or its fruit. [L. oliva] inferior o. SYN: oliva. superior o. SYN: dorsal nucleus of trapezoid body.

olive oil
See under oil.

olivifugal (ol′i-vif′u-gal)
In a direction away from the olive. [oliva + L. fugio, to flee]

olivipetal (ol′i-vip′e-tal)
In a direction toward the olive. [oliva + L. peto, to seek]

olivocochlear (ol′i-vo-kok′le-ar)
See o. tract.

olivopontocerebellar (ol′i-vo-pon′to-sar-e-bel′ar)
Relating to the olivary nucleus, basis pontis, and cerebellum.

Ollendorf
Helene, German dermatologist, fl. 1928. See Buschke-O. syndrome.

Ollier
Louis X.E.L., French surgeon, 1830–1900. See O. graft, O. disease, O. theory, O.-Thiersch graft.

Olmsted
H.C., 20th century U.S. pediatrician. See O. syndrome.

-ology
See -logia.

ololiuqui (o-lo-lu′ke)
A hallucinogen used in ceremonies by the Aztec Indians in Mexico; contains ergot alkaloids and derivatives of lysergic acid. SEE ALSO: Rivea corymbosa, Ipomoea rubrocoerulea praecox.

olophonia (ol′o-fo′ne-a)
Impaired speech caused by an anatomical defect in the vocal organs. [G. oloos, destroyed, lost, + phone, voice]

Olszewski
Jerzy, Polish-Canadian neuropathologist, 1913–1964. See Steele-Richardson-O. disease, Steele-Richardson-O. syndrome.

-oma
A tumor or neoplasm. [G. -oma, suffix forming nouns from some verb stems]

-omata
Plural of -oma.

Ombrédanne
Louis, French surgeon, 1871–1956. See O. operation.

ombrophobia (om-bro-fo′be-a)
Morbid fear of rain. [G. ombros, rainstorm, + phobos, fear]

Omenn
Gilbert S., U.S. internist, *1941. See O. syndrome.

omental (o-men′tal)
Relating to the omentum. SYN: epiploic.

omentectomy (o-men-tek′to-me)
Resection or excision of the omentum. SYN: omentumectomy. [omentum + G. ektome, excision]

omentitis (o-men-ti′tis)
Peritonitis involving the omentum. [L. omentum + G. -itis, inflammation]

omento-, oment-
The omentum. SEE ALSO: epiplo-. [L. omentum]

omentofixation (o-men′to-fik-sa′shun)
SYN: omentopexy.

omentopexy (o-men′to-pek-se)
1. Suture of the greater omentum to the abdominal wall to induce collateral portal circulation. 2. Suture of the omentum to another organ to increase arterial circulation. SEE ALSO: omentoplasty. SYN: omentofixation. [omento- + G. pexis, fixation]

omentoplasty (o-men′to-plas-te)
Use of greater omentum to cover or fill a defect, augment arterial or portal venous circulation, absorb effusions, or increase lymphatic drainage. SEE ALSO: omentopexy. [omento- + G. plastos, formed]

omentorrhaphy (o-men-tor′a-fe)
Suture of an opening in the omentum. [omento- + G. rhaphe, suture]

omentovolvulus (o-men-to-vol′vu-lus)
Twisting of the omentum on a pedicile.

omentulum (o-men′tu-lum)
SYN: lesser omentum. [Mod. L. dim. of omentum]

omentum, pl .omenta (o-men′tum, -ta) [TA]
A fold of peritoneum passing from the stomach to another abdominal organ. [L. the membrane that encloses the bowels] gastrocolic o. SYN: greater o.. gastrohepatic o. SYN: lesser o.. gastrosplenic o. SYN: gastrosplenic ligament. greater o. [TA] an areolar, four-layer peritoneal fold, formed by the double-layer dorsal mesentery of the stomach (dorsal mesogastrium) descending from the greater curvature of the stomach to fold under on itself and ascend to the transverse colon; the descending and ascending portions fuse, obliterating the inferior recess of the omental bursa, resulting in the four-layer structure that usually hangs over the anterior aspect of the intestines like an apron; components include the following peritoneal ligaments: gastrophrenic, gastrosplenic, splenorenal, and gastrocolic. SYN: o. majus [TA] , caul (2) , cowl, epiploon, gastrocolic o., pileus, velum (3) . lesser o. [TA] a thin, double-layer peritoneal fold formed by the ventral mesentery of the stomach (ventral mesogastrium) passing from the lesser curvature of the stomach and upper border to the proximal duodenum (2 cm distal to the pylorus) to the liver (margins of the porta hepatis and into the depth of the fissure of the ductus venosus); major subcomponents include the hepatogastric ligament (main sheetlike portion) and the hepatoduodenal ligament (thickened free right border, which encloses the hepatic artery, portal vein, and common bile duct. SYN: o. minus [TA] , gastrohepatic o., omentulum. o. majus [TA] SYN: greater o.. o. minus [TA] SYN: lesser o..

omentumectomy (o-men-tu-mek′to-me)
SYN: omentectomy.

omeprazole (o-me′pra-zol)
A drug that blocks the transport of hydrogen ions into the stomach and is used as an antiulcerative and in treatment of Zollinger-Ellison syndrome.

Ommaya
Ayub K., U.S. neurosurgeon, *1930. See O. reservoir.

omn. hor.
Abbreviation for L. o., every hour.

omnipotence of thought (om-nip′o-tens)
A childish or magical thought process whereby instantaneous gratification of fantasies and wishes is believed to be imminent.

omnivorous (om-niv′o-rus)
Living on food of all kinds, upon both animal and vegetable food. [L. omnis, all, + voro, to eat]

omo-
The shoulder (sometimes including the upper arm). [G. omos, shoulder]

omoclavicular (o′mo-kla-vik′u-lar)
Relating to the shoulder and the clavicle; denoting an anomalous muscle attached to the coracoid process or upper edge of the scapula and to the clavicle.

omohyoid (o-mo-hi′oyd)
SYN: o. (muscle).

omophagia (o-mo-fa′je-a)
The eating of raw food, especially of raw flesh. [G. omos, raw, + phago, to eat]

omothyroid (o-mo-thi′royd)
Denoting a band of muscular fibers passing between the superior cornu of the thyroid cartilage and the omohyoid muscle.

OMP
Abbreviation for oligo-N-methylmorpholinium propylene oxide; orotidylic acid; orotidylate; orotidine 5′-monophosphate.

OMPA
Abbreviation for octamethyl pyrophosphoramide.

OMP decarboxylase
SYN: orotidylic acid decarboxylase.

omphal-, omphalo-
The umbilicus, the navel. [G. omphalos, navel (umbilicus)]

omphalectomy (om-fa-lek′to-me)
Excision of the umbilicus or of a neoplasm connected with it. [omphal- + G. ektome, excision]

omphalelcosis (om′fal-el-ko′sis)
Ulceration at the umbilicus. [omphal- + G. helkosis, ulceration]

omphalic (om-fal′ik)
SYN: umbilical. [G. omphalos, umbilicus]

omphalitis (om-fa-li′tis)
Inflammation of the umbilicus and surrounding parts.

omphalo-
See omphal-.

omphaloangiopagus (om′fa-lo-an-je-op′a-gus)
Unequal conjoined twins in which the parasite derives its blood supply from the placenta of the autosite. See conjoined twins, under twin. SYN: allantoidoangiopagus. [omphalo- + G. angeion, vessel, + pagos, something fixed]

omphalocele (om′fal-o-sel, om′fa-lo-)
Congenital herniation of viscera into the base of the umbilical cord, with a covering membranous sac of peritoneum-amnion. The umbilical cord is inserted into the sac here, in contradistinction to its attachment in gastroschisis. SEE ALSO: umbilical hernia. SYN: amniocele, exomphalos (3) , exumbilication (3) . [omphalo- + G. kele, hernia]

omphaloenteric (om′fa-lo-en-tar-ik)
Relating to the umbilicus and the intestine.

omphalomesenteric (om′fa-lo-mez-en-tar′ik)
1. Term denoting relationship of the midgut to the yolk sac. As the head and tail folds of the embryo continue to form, this relationship is diminished and is represented by a narrow yolk stalk or vitelline duct. 2. Relating to the vitelline duct.

omphalopagus (om′fa-lop′a-gus)
Conjoined twins united at their umbilical regions. See conjoined twins, under twin. SYN: monomphalus. [omphalo- + G. pagos, something fixed]

omphalophlebitis (om′fa-lo-fle-bi′tis)
Inflammation of the umbilical veins. [omphalo- + G. phleps, vein, + -itis, inflammation]

omphalorrhagia (om′fa-lo-ra′je-a)
Bleeding from the umbilicus. [omphalo- + G. rhegnymi, to burst forth]

omphalorrhea (om′fa-lo-re′a)
A serous discharge from the umbilicus. [omphalo- + G. rhoia, flow]

omphalorrhexis (om′fa-lo-rek′sis)
Rupture of the umbilical cord during childbirth. [omphalo- + G. rhexis, rupture]

omphalos (om′fa-los)
Rarely used term for umbilicus. [G. navel]

omphalosite (om′fa-lo-sit)
Underdeveloped twin of allantoidangiopagous twin; joined by umbilical vessels. SYN: placental parasitic twin. [omphalo- + G. sitos, food]

omphalospinous (om′fa-lo-spi′nus)
Denoting a line connecting the umbilicus and the anterior superior spine of the ilium, on which lies the McBurney point.

omphalotomy (om-fa-lot′o-me)
Cutting of the umbilical cord at birth. [omphalo- + G. tome, incision]

omphalotripsy (om′fa-lo-trip′se)
Crushing, instead of cutting, the umbilical cord after childbirth. [omphalo- + G. tripsis, a rubbing]

omphalovesical (om′fa-lo-ves′i-kal)
SYN: vesicoumbilical.

omphalus (om′fa-lus)
Rarely used term for umbilicus. [G. omphalos, navel]

OMP pyrophosphorylase
SYN: orotate phosphoribosyltransferase.

oncho-
See onco-.

Onchocerca (ong-ko-ser′ka)
A genus of elongated filariform nematodes (family Onchocercidae) that inhabit the connective tissue of their hosts, usually within firm nodules in which these parasites are coiled and entangled. SYN: Oncocerca. [G. onkos, a barb, + kerkos, tail] Onchocerca volvulus the blinding nodular worm, a species that causes onchocerciasis.

onchocerciasis (ong′ko-ser-ki′a-sis)
Infection with Onchocerca (especially O. volvulus, a filarial nematode transmitted from person to person by black flies of the genus Simulium), marked by nodular swellings forming a fibrous cyst enveloping the coiled parasites (onchocercoma); microfilariae move freely out of the nodule and escape into the intercellular lymph in the dermis. Dermatologic changes often develop, especially in Africa, resulting in intense pruritus, scaly or lichenoid skin, depigmentation, and destruction of elastic fibers. Most important are the ocular complications that may develop after a long chronic course, with blindness frequently occurring in advanced cases, caused by the presence of living or dead microfilariae seen by slitlamp biomicroscopy. SYN: blinding disease, onchocercosis, volvulosis. ocular o. ocular complications, such as keratitis, iridocyclitis, or retrobulbar neuritis, caused by the microfilariae of Onchocerca volvulus. SYN: river blindness.

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