A sugar containing eight carbon atoms.
The -onic acid formally formed by oxidation of carbon atom 1 of octulose to a carboxylic acid group; a condensation product of d-arabinose and phosphoenolpyruvate analogous to ...
Having to do with the eye. In a microscope, the lens closest to the eye is termed the ocular (the eyepiece) whereas the objective (also called the objective lens) is the lens ...
That part of the conjunctiva, a clear membrane of the eye, which covers the outer surface of the eye. The other part of the conjunctiva is the palpebral conjunctiva, which lines ...
One skilled in the design, fabrication, and fitting of artificial eyes and the making of prostheses associated with the appearance or function of the eyes. [L. oculus, eye]
SYN: ophthalmic ointment. [Mod. L., fr. L. oculus, eye]
Plural of oculus. [L.]
SYN: ophthalmologist. [L. oculus, eye]
The eye, ocular. SEE ALSO: ophthalmo-. [L. oculus]
Pain in the eyeball. SYN: ophthalmalgia. [ophthalmo- + G. algos, pain]
A method of recording eye position and movements. [ oculo- + G. graphe, a writing]
- photosensor o. o. in which photocells are directed to the surface of the eye to record ...
The limits of rotation of the eyeballs. [ oculo- + G. gyros, circle]
Referring to rotation of the eyeballs; characterized by oculogyria.
Pertaining to the o. cranial nerve. [L. oculomotorius, fr. oculo- + L. motorius, moving]
The oculomotor nerve is the third cranial nerve. (The cranial nerves emerge from or enter the cranium, the skull, as opposed to the spinal nerves which emerge from the ...
Relating to the eyes and the nose. [ oculo- + L. nasus, nose]
Indirect measurement of the hemodynamic significance of internal carotid artery stenosis or occlusion by demonstration of an ipsilateral delay in the arrival of ocular pressure ...
A method of bilateral measurement of ophthalmic artery pressure that reflects pressure and flow in the internal carotid artery. See oculoplethysmography.
Pertaining to the sympathetic pathway to the eye, damage to which produces Horner syndrome.
Relating to the orbit or its margin and the zygomatic bone.
SYN: oxytocin. [G. okytokos, fast birth, prompt delivery]
Abbreviation for overdose; optic density (see absorbance).
OD (lens prescription)
Abbreviation of " oculus dexter." Latin for "right eye." (The words "dexterity" and "dextrous" derive from " dexter" since the right hand is usually more skillful than the left.) ...
A biting sensation; a form of paresthesia. [G. odaxesmos, an irritation, fr. odax (adv.), by biting.]
1. Causing formication or itching. 2. A substance or agent that causes formication or itching. [G. odaxesmos, an irritation]
Ruggero, Italian physician; 1864–1913. See O. sphincter.
The ratio of probability of occurrence to non-occurrence of an event. [pl. of odd, fr. M.E. odde, fr. O.Norse oddi, odd number]
SYN: neurocladism. [G. hodos, path, + genesis, source]
Obsolescent term for toothache thought to be of gouty origin. [ odonto- + G. agra, seizure]
SYN: toothache. [odont- + G. algos, pain]
- o. dentalis reflex pain in the ear due to dental disease, usually propagated along the auriculotemporal nerve.
Removal of teeth by the reflection of a mucoperiosteal flap and excision of bone from around the root or roots before the application of force to effect the tooth removal. ...
Chattering of the teeth. [odont- + G. erismos, quarrel]
1. Resembling dentin. 2. A small excrescence from a tooth, most common on the root or neck. 3. Toothlike.
One of the dentin-forming cells, derived from mesenchyme of neural crest origin, lining the pulp cavity of a tooth; odontoblasts are arranged in a peripheral layer in the dental ...
1. A tumor composed of neoplastic epithelial and mesenchymal cells that may differentiate into cells able to produce calcified tooth substances. 2. An odontoma in its early ...
One of the cells believed to produce resorption of the roots of the deciduous teeth. [ odonto- + G. klastos, broken]
SYN: toothache. [ odonto- + G. odyne, pain]
A developmental disturbance of one or of several adjacent teeth, of unknown etiology, characterized by deficient formation of enamel and dentin, which results in an abnormally ...
The process of development of the teeth. SYN: odontogeny, odontosis. [ odonto- + G. genesis, production]
- o. imperfecta SYN: odontodysplasia.
1. Shaped like a tooth. SYN: dentoid. 2. Relating to the toothlike o. process of the second cervical vertebra. [odont- + G. eidos, resemblance]
SYN: dentistry. [ odonto- + G. logos, study]
- forensic o. SYN: forensic dentistry.
SYN: erosion (3). [ odonto- + G. lysis, dissolution]
1. A tumor of odontogenic origin. 2. A hamartomatous odontogenic tumor composed of enamel, dentin, cementum, and pulp tissue that may or may not be arranged in the form of a ...
Dental nomenclature. [ odonto- + G. onoma, name]
SYN: dentistry. [ odonto- + G. nosos, disease, + logos, study]
Irregularity of the teeth. SYN: odontoloxia, odontoloxy. [ odonto- + G. parallax, alternately]
Any disease of the teeth or of their sockets. [ odonto- + G. pathos, suffering]
Morbid fear of teeth. [ odonto- + G. phobos, fear]
Surgical contouring of tooth surface to enhance plaque control and gingival morphology. [ odonto- + G. plasso, to mold]
Grinding together of the teeth. SEE ALSO: bruxism. [ odonto- + G. prisis, a sawing, a grinding]
Downward movement of an upper tooth due to the loss of its lower antagonist(s). SEE ALSO: supereruption. [ odonto- + G. ptosis, a falling]
Profuse bleeding from the socket after the extraction of a tooth. [ odonto- + G. rhegnymi, to burst forth]
Fissure of a tooth. [ odonto- + G. schisma, a cleft]
An optical device, similar to a closed circuit television system, that projects a view of the oral cavity onto a screen for multiple viewing.
1. Examination of the oral cavity by means of the odontoscope. 2. Examination of the markings in prints of the cutting edges of the teeth; used, like fingerprints, as a method ...
Cutting into the crown of a tooth. [ odonto- + G. tome, incision]
- prophylactic o. a preventive operation in which imperfectly formed developmental grooves, pits, and fissures ...
Emanation from any substance that stimulates the olfactory sensory cells. SYN: scent, smell (3). [L.]
See lathyrism. [fr. Lathyrus odoratus, sweet pea]
Having a scent, perfume, or odor. SYN: odorous. [odor + L. fero, to bear]
The determination of the comparative power of different substances in stimulating olfactory sensations. [odor + G. metron, measure]
Conveying or bearing an odor, as in the air. [odor + L. vector, a carrier]
Description of odors. [odor + G. graphe, a description]
Hypersensitiveness of the organ of hearing, so that sounds cause actual pain. [odyn- + G. akouo, to hear]
Pain on swallowing. [odyno- + G. phago to eat]
Pain on using the voice. [odyno- + G. phone, sound, voice]
For words so beginning and not found here, see e-.
1. Manifestation of the Oedipus complex. 2. Rarely used term for self-infliction of injury to the eyes, usually an attempt at evulsion. [Oedipus, G. myth. char.]
Eusebio, Italian anatomist, 1827–1903. See O. muscles, under muscle.
A unit of magnetic field intensity; the magnetic field intensity that exerts a force of 1 dyne on a unit magnetic pole; equal to (1000/4π) A m−1. [Hans-Christian O., Danish ...
Infection with nematode parasites of the genus Oesophagostomum. SYN: esophagostomiasis. [G. oi-sophagos, gullet (esophagus), + stoma, mouth, + -iasis, condition]
A genus of strongyle nematodes ( subfamily Oesophagostominae) that encyst in the intestinal wall of herbivores and primates, causing nodular disease. Larvae appear to stimulate ...
Common name for botflies of the family Oestridae, such as Oestrus. [G. oistros, gadfly]
Infection of small ruminants and, rarely, humans with larvae of the fly Oestrus ovis.
A genus of tissue-invading flies that cause myiasis in sheep; the head botflies in the family Oestridae. O. ovis (a nose fly) is a grayish brown, robust, hairy, beelike botfly, ...
In the United States, the regulations of the Food and Drug Administration (FDA) permit physicians to prescribe approved medications for other than their intended indications. ...
Authoritative; denoting a drug or a chemical or pharmaceutical preparation recognized as standard in the pharmacopeia. Cf.:officinal. [L. officialis, fr. officium, a favor, ...
Denoting a chemical or pharmaceutical preparation kept in stock, in contrast to magistral (prepared extemporaneously according to a physician's prescription); an o. preparation ...
The offspring are strictly speaking the progeny, or young, born to a person. In a larger sense, the offspring are collectively all of the descendants, brood or family. For ...
Kyusaka, 20th century Japanese physician. See O.-Knaus rule.
Sir Alexander, Scottish surgeon, 1844–1929. See O. line, O.-Luc operation.
Chita, Japanese ophthalmologist, 1875–1945. See O. disease.
Joseph H., U.S. otolaryngologist, 1915–1983. See O. operation.
Abbreviation for Oral Hygiene Index.
Abbreviation for Simplified Oral Hygiene Index.
Georg S., German physicist, 1787–1854. See o., O. law.
The practical unit of electrical resistance; the resistance of any conductor allowing 1 A of current to pass under the electromotive force of 1 V. [G.S. O.]
An instrument for determining the resistance, in ohms, of a conductor.
Term used to designate the nonspreading growth of nonflagellated bacteria on agar media; also applied to somatic agglutination. SEE ALSO: O antigen. [Ger. without breath]
Abbreviation for osteogenesis imperfecta.
For words so beginning and not found here, see e-.
Formerly used term for arthroconidium. [Mod. L. dim. of G. oon, egg]
An inflammable liquid, of fatty consistency and unctuous feel, which is insoluble in water, soluble or insoluble in alcohol, and freely soluble in ether. Oils are variously ...
Coconut, palm kernel or palm oil. Like all fats and oils, these three oils contain various types of fatty acids but, unlike other plant oils, they contain a great deal of ...
A medication preparation that is applied topically (onto the skin). An ointment has an oil base whereas a cream is water-soluble. (The word ointment comes from the Latin ungere ...
Reiji (1930–1975) and Tuneko, 20th century Japanese molecular biologists. See O. fragment.
USAN-approved contraction for ethanolamine.
Michael C., 20th century English physician. See O. syndrome.
Oily or greasy. [L. oleagineus, pertaining to olea, the olive tree]
The bark and leaves of Nerium o. (family Apocynaceae), a shrub of the eastern Mediterranean; formerly used as a diuretic and heart tonic.
An antibiotic substance produced by species of Streptomyces antibioticus; effective against staphylococci, streptococci, pneumococci, and some Gram-negative bacteria.
1. A salt of oleic acid. 2. A pharmacopeial preparation consisting of a combination or solution of an alkaloid or metallic base in oleic acid, used as an inunction.
Of or pertaining to the bony tip of the elbow. The olecranon is, in fact, the near end of the ulna, the bone in the forearm, that forms the pointed portion of the elbow. The ...
An unsaturated fatty acid that is the most widely distributed and abundant fatty acid in nature; used commercially in the preparation of oleates and lotions, and as a ...
Trioleoyl glycerol; glyceryl trioleate; a triacylglycerol, solely containing oleoyl moieties, found in fats and oils. SYN: triolein.
Oil. SEE ALSO: eleo-. [L. oleum]
An instrument, similar to a hydrometer, for determining the specific gravity of oils. SYN: eleometer. [ oleo- + G. metron, measure]
1. A compound of an essential oil and resin, present in certain plants. 2. A pharmaceutical preparation. See aspidium, capsicum, ginger. 3. SYN: balsam.
A class of preparations made by the trituration of a volatile oil (such as anise, fennel, or lemon) with sugar; used as a diluent or corrigent of powerful or bad-tasting ...
Greasy; relating to abnormality of the sebaceous apparatus. [L., fr. oleum, oil]
Treatment of disease by an oil given internally or applied externally. SYN: eleotherapy. [ oleo- + G. therapeia, therapy]
A solution of a vitamin in an edible oil.
- o. A and D a solution of vitamins A and D in fish liver oil or in an edible vegetable oil.
A mixture of aliphatic alcohols consisting chiefly of CH3(CH2)7CH=CH(CH2)7CH2OH; used as an emulsifying aid and in the preparation of cold cream; found in fish oils.
A product of the Δ9-desaturase enzyme system in the biosynthesis of monounsaturated fatty acid s. SYN: oleyl- coenzyme A.
The unit of smell; the threshold of olfactory stimulation, or the point at which the smell is just received in the olfactometer. [see olfaction]
The sense of smell. Olfactory apparatus: The whole system needed to have a sense of smell.
* * *
1. The sense of smell. SYN: smell (2). 2. The act of smelling. SYN: osmesis, ...
Study of the sense of smell. [ olfaction + G. logos, study]
A device for estimating the sensitivity to odorants. [L. olfactus, smell, + G. metron, measure]
Determination of the degree of sensitivity to odorants.
Morbid fear of odors. SYN: osmophobia, osphresiophobia. [L. olfactus, smell, + G. phobos, fear]
Relating to the sense of smell. SYN: osmatic, osphretic. [see olfaction]
The nerve that carries impulses for the sense of smell from the nose to the brain. The olfactory nerve is the first cranial nerve. The cranial nerves emerge from or enter the ...
A gum resin from several trees of the genus Boswellia (family Burseraceae); has been used as a stimulant expectorant in bronchitis, for fumigations, and as incense. SYN: ...
A deficiency in the amount of blood in the body or any organ or tissue. [oligo- + G. haima, blood]
Pertaining to or characterized by oligemia.
In molecular genetics, oligonucleotide.
Means just a few or scanty. From the Greek "oligos', few, scanty. Examples of terms starting with oligo- include oligodactyly (few fingers), oligohydramnios (too little ...
1. A few, a little; too little, too few. 2. In chemistry, used in contrast to “poly-” in describing polymers; e.g., oligosaccharide. [G. oligos, few]
A glucanohydrolase cleaving α-1,6 links in isomaltose and dextrins produced from starch and glycogen by α-amylase; secreted into the duodenum; a deficiency of this enzyme ...
A deficient secretion of bile. [oligo- + G. chole, bile]
A deficiency of gastric juice. [oligo- + G. chylos, juice]
A deficiency of chyme. [oligo- + G. chymos, juice]
Consisting of only a few cysts, as occasionally observed in certain examples of hydatidiform mole and other lesions that ordinarily have numerous cysts. [oligo- + G. kystis, ...
Fewer than the normal number of fingers or toes. Oligo- is from the Greek “oligos” (few or scanty) + -dactyly from the Greek “dactylos” (finger) = few fingers. ...
A primitive glial cell that is the normal precursor cell of the oligodendrocyte.
Obsolete term for oligodendroglioma. [oligo- + G. dendron, tree, + blastos, germ, + -oma]
: A type of cell in the central nervous system. The oligodendrocytes surround and insulate the long fibers (the axons) through which the nerves send their electrical messages. ...
One of the three types of glia cells (the other two being macroglia or astrocytes, and microglia) that, together with nerve cells, compose the tissue of the central nervous ...
: A type of brain tumor that is derived from oligodendrocytes which are cells in the central nervous system that surround and insulate the long fibers (the axons) through which ...
Abnormal lack of thirst. SEE ALSO: hypodipsia. [oligo- + G. dipsa, thirst]
SYN: hypodontia. [oligo- + G. odous, tooth]
Active in very small quantity; e.g., the germicidal effect of an exceedingly dilute solution (such as one to one hundred million) of copper in distilled water. [oligo- + G. ...
Slight or scant secretion of milk. [oligo- + G. gala, milk]
The presence of an insufficient amount of amniotic fluid (less than 300 mL at term). SYN: hypamnion, hypamnios, oligamnios, oligoamnios. [oligo- + G. hydor, water, + amnion] ...
Obsolete term for excretion of small quantities of urine, as seen in dehydration. [oligo- + G. hydor, water, + ouron, urine]
Having little yolk; denoting an egg in which there is only a little scattered deutoplasm. [oligo- + G. lekithos, yolk]
Scant menstruation. Less menstrual blood flow than usual.
* * *
Scanty menstruation. [oligo- + menorrhea]
A polymer containing only a few repeating units, a “few” generally considered as fewer than 20.
Presenting few changes of form; not polymorphic. [oligo- + G. morphe, form]
A small DNA molecule composed of a few nucleotide bases. The term "oligonucleotide" applies similarly to RNA.
* * *
A compound made up of the condensation of a small number ...
A peptide whose molecule contains a few amino acid residues up to about 20.
SYN: mental retardation.
- phenylpyruvate o. SYN: phenylketonuria.
Deficient in reparative power. [oligo- + G. plasso, to form]
SYN: hypopnea. [oligo- + G. pnoe, breath]
A scanty secretion of saliva. SYN: oligosialia. [oligo- + G. ptyalon, saliva]
A rarely used term for an abnormal indifference toward or dislike of persons or things. [G. o., negligence, slight esteem, fr. oligos, little, + ora, care, regard]
A compound made up of the condensation of a small number of monosaccharide units. Cf.:polysaccharide.
SYN: oligoptyalism. [oligo- + G. sialon, saliva]
Fewer sperm than normal. Azoospermia, by contrast, means absolutely no sperm at all.
Referring to neural conduction pathways that are interrupted by only a few synaptic junctions, i.e., made up of a sequence of only few nerve cells, in contrast to polysynaptic ...
Rarely used term for a poverty or loss of affect. [oligo- + -thymia]
A subnormal concentration of spermatozoa in the penile ejaculate. SYN: oligospermia, oligospermatism, oligozoospermatism. [oligo- + G. zoos, living, + sperma, seed, semen, + ...
Scanty urine production. [oligo- + G. ouron, urine]
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 ...
1. Relating to the oliva. 2. Relating to or shaped like an olive.
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 ...
In a direction away from the olive. [ oliva + L. fugio, to flee]
In a direction toward the olive. [ oliva + L. peto, to seek]
Helene, German dermatologist, fl. 1928. See Buschke-O. syndrome.
Louis X.E.L., French surgeon, 1830–1900. See O. graft, O. disease, O. theory, O.- Thiersch graft.
A condition characterized by multiple enchondromas — benign masses of cartilage growing within bones. An enchondroma can deform and shorten a limb and predispose to a fracture ...
H.C., 20th century U.S. pediatrician. See O. syndrome.
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 ...
Impaired speech caused by an anatomical defect in the vocal organs. [G. oloos, destroyed, lost, + phone, voice]
Jerzy, Polish-Canadian neuropathologist, 1913–1964. See Steele-Richardson-O. disease, Steele-Richardson-O. syndrome.
Louis, French surgeon, 1871–1956. See O. operation.
Morbid fear of rain. [G. ombros, rainstorm, + phobos, fear]
Omega-3 fatty acids
A class of fatty acids found in fish oils, especially from salmon and other cold-water fish, that acts to lower the levels of cholesterol and LDL (low-density lipoproteins) in ...
Gilbert S., U.S. internist, *1941. See O. syndrome.
Relating to the omentum. SYN: epiploic.
Resection or excision of the omentum. SYN: omentumectomy. [ omentum + G. ektome, excision]
Peritonitis involving the omentum. [L. omentum + G. -itis, inflammation]
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 ...
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- ...
Suture of an opening in the omentum. [omento- + G. rhaphe, suture]
SYN: lesser omentum. [Mod. L. dim. of omentum]
A sheet of fat that is covered by peritoneum. The greater omentum is attached to the bottom edge of the stomach, and hangs down in front of the intestines. Its other edge is ...
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.
Ayub K., U.S. neurosurgeon, *1930. See O. reservoir.
: A device implanted under the scalp that is used to deliver anticancer drugs to the cerebrospinal fluid, the fluid surrounding the brain and spinal cord. The device is named for ...
Abbreviation for L. o., every hour.
omnipotence of thought
A childish or magical thought process whereby instantaneous gratification of fantasies and wishes is believed to be imminent.