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Medical Dictionary


step (step)
1. In dentistry, a dove-tailed or similarly shaped projection of a cavity prepared in a tooth into a surface perpendicular to the main part of the cavity for the purpose of preventing displacement of the restoration (filling) by the force of mastication. 2. A change in direction resembling a stair-s. in a line, a surface, or the construction of a solid body. Krönig steps extension of the lower part of the right border of absolute cardiac dullness in hypertrophy of the right heart. R&slash;onne nasal s. a nasal visual field defect with one margin corresponding to the retinal horizontal medium; seen in glaucoma.

stephanial (ste-fa′ne-al)
Pertaining to the stephanion.

stephanion (ste-fa′ne-on)
A craniometric point where the coronal suture intersects the inferior temporal line. [G. dim. of stephanos, crown]

Stephanofilaria (stef′a-fi-lar′e-a)
A genus of Filaroid nematodes in the family Stephanofilariidae, subcutaneous parasites of large mammals, especially cattle. S. stilesi a skin-infecting species of filaria parasitic in cattle and transmitted by the horn fly, Haematobia irritans; the only species known to occur in the U.S.; characterized by a row of spines behind the mouth of the adult worm, which is 6–8 mm in the female, 2–3 mm in the male. Both adults and larvae are found in granulomatous skin lesions in cattle, usually on the underside of the abdomen. [G. stephanos, crown, + filaria]

Stephanurus dentatus (stef-a-noo′rus)
The kidney worm or lard worm of swine, a strongyle nematode parasite species that also occurs, though rarely, in the liver of cattle. Adult worms in swine live in the perirenal fat, the kidney pelvis, or as erratic forms in many other locations. Eggs are passed through the urine and infection is direct, by ingestion of infective larvae or by skin infection, or indirect, by ingestion of earthworms in which the larvae can survive. [G. stephanos, crown, + oura, tail]

steppage (step′aj)
SYN: s. gait. [Fr.]

steradian (sr) (ste-ra′de-an)
The unit of solid angle; the solid angle that encloses an area on the surface of a sphere equivalent to the square of the radius of the sphere. [G. stereos, solid, + radion, radius]

sterane (ster′an, ster′an)
The hypothetical parent molecule for any steroid hormone; a saturated hydrocarbon compound that contains no oxygen. The name was originally conceived to achieve forms of systematic nomenclature, but is now supplanted by the fundamental variants: gonane, estrane, androstane, norandrostane (etiane), cholane, cholestane, ergostane, and stigmastane. SEE ALSO: steroids.

Feces. SEE ALSO: copro-, scato-. [L. stercus, excrement]

stercobilin (ster′ko-bi′lin, -bil′in)
A brown degradation product of hemoglobin, present in the feces. SEE ALSO: bilirubinoids.

stercolith (ster′ko-lith)
SYN: fecalith. [sterco- + G. lithos, stone]

stercoraceous (ster-ko-ra′shus)
Relating to or containing feces. SYN: stercoral, stercorous.

stercoral (ster′ko-ral)
SYN: stercoraceous.

stercorin (ster′ko-rin)
SYN: coprosterol.

stercoroma (ster-ko-ro′ma)
SYN: fecaloma. [sterco- + G. -oma, tumor]

stercorous (ster′ko-rus)
SYN: stercoraceous.

stercus (ster′kus)
SYN: feces. [L. feces, excrement]

stere (ster, star)
A measure of capacity; equivalent to a cubic meter or a kiloliter; equal to 1.307951 cubic yards. [Fr. fr. G. stereos, solid]

1. A solid; a solid condition or state. 2. Spatial qualities, three-dimensionality. [G. stereos, solid]

stereoagnosis (ster′e-o-ag-no′sis)
SYN: tactile agnosia.

stereoanesthesia (ster′e-o-an-es-the′ze-a)
SYN: tactile agnosia. [stereo- + G. an- priv. + aisthesis, sensation]

stereoarthrolysis (ster′e-o-ar-throl′i-sis)
Production of a new joint with mobility in cases of bony ankylosis. [stereo- + G. arthron, joint, + lysis, loosening]

stereocampimeter (ster′e-o-kam-pim′e-ter)
An apparatus for studying the central visual fields while the fellow eye holds fixation. [stereo- + L. campus, field, + G. metron, measure]

stereochemical (ster′e-o-kem′i-kal)
Relating to stereochemistry.

stereochemistry (ster-e-o-kem′is-tre)
The branch of chemistry concerned with the spatial three-dimensional relations of atoms in molecules, i.e., the positions the atoms in a compound bear in relation to one another in space.

stereocilium, pl .stereocilia (ster′e-o-sil′e-um, -a)
A nonmotile long microvillus. [stereo- + L. cilium, eyelid]

stereocinefluorography (ster′e-o-sin′e-flor-og′ra-fe)
Obsolete practice of recording on motion picture film the images obtained by stereoscopic fluoroscopy; three-dimensional views are obtained.

stereocolpogram (ster′e-o-kol′po-gram)
Picture taken with the stereocolposcope.

stereocolposcope (ster′e-o-kol′po-skop)
Instrument that provides the observer with a magnified three-dimensional gross inspection of the vagina and cervix. [stereo- + G. kolpos, a hollow (vagina), skopeo, to view]

stereoelectroencephalography (ster-e-o-e-lek′tro-en-sef-a-log′ra-fe)
Recording of electrical activity in three planes of the brain, i.e., with surface and depth electrodes.

stereoencephalometry (ster′e-o-en-sef′a-lom′e-tre)
The localization of brain structures by use of three-dimensional coordinates.

stereognosis (ster′e-og′no′sis)
The appreciation of the form of an object by means of touch. [stereo- + G. gnosis, knowledge]

stereognostic (ster′e-og-nos′tik)
Relating to stereognosis.

stereogram (ster′e-o-gram)
A stereoscopic radiographic image of a pair.

stereograph (ster′e-o-graf)
A stereoscopic x-ray apparatus.

stereography (ster-e-og′ra-fe)
SYN: stereoradiography.

stereoisomer (ster′e-o-i′so-mer)
A molecule containing the same number and kind of atom groupings as another but in a different arrangement in space; the stereoisomers are not interconvertible unless bonds are broken and reformed, by virtue of which it exhibits different optic properties, e.g., as between d- and l-amino acids, 5α- and 5β-steroids. Cf.:isomer. [stereo- + G. isos, equal, + meros, part]

stereoisomeric (ster′e-o-i-so-mer′ik)
Relating to stereoisomerism.

stereoisomerism (ster′e-o-i-som′er-izm)
Molecular asymmetry, isomerism involving different spatial arrangements of the same groups ( e.g., androsterone and isoandrosterone, differing only in that one has a 3α-OH, the other a 3β-OH). SEE ALSO: stereoisomer, Le Bel-van't Hoff rule. SYN: stereochemical isomerism.

stereology (ster′e-ol′o-je)
A study of the three-dimensional aspects of a cell or microscopic structure. [stereo- + G. logos, study]

stereometer (ster-e-om′e-ter)
An instrument used in stereometry. [stereo- + G. metron, measure]

stereometry (ster-e-om′e-tre)
1. Measurement of a solid object or the cubic capacity of a vessel. 2. Determination of the specific gravity of a liquid.

stereo-orthopter (ster′e-o-or-thop′ter)
A type of stereoscope used in visual training. [stereo- + G. orthos, straight, + optikos, optical]

stereopathy (ster-e-op′a-the)
Persistent stereotyped thinking.

stereophorometer (ster′e-o-fo-rom′e-ter)
A phorometer with a stereoscopic attachment.

stereophotomicrograph (ster′e-o-fo′to-mi′kro-graf)
A stereoscopic photomicrograph that, when viewed with a stereoscope, appears three dimensional.

stereopsis (ster-e-op′sis)
SYN: stereoscopic vision. [stereo- + G. opsis, vision]

stereoradiography (ster′e-o-ra-de-og′ra-fe)
Preparation of a pair of radiographs with appropriate shift of the x-ray tube or film so that the images can be viewed stereoscopically to give a three-dimensional appearance. SYN: stereography, stereoroentgenography.

stereoroentgenography (ster′e-o-rent′gen-og′ra-fe)
SYN: stereoradiography.

stereoscope (ster′e-o-skop)
An instrument producing two horizontally separated images of the same object, providing a single image with an appearance of depth. [stereo- + G. skopeo, to view]

stereoscopic (ster′e-o-skop′ik)
Relating to a stereoscope, or giving the appearance of three dimensions.

stereoscopy (ster-e-os′ko-pe)
1. An optic technique by which two images of the same object are blended into one, giving a three-dimensional appearance to the single image. 2. See radiostereoscopy.

stereoselective (ster′e-o-se-lek′tiv)
As applied to a reaction, denoting a process in which of two or more possible stereoisomeric products only one predominates; a s. process is not necessarily stereospecific.

stereospecific (ster′e-o-spe-sif′ik)
As applied to a reaction, denoting a process in which stereoisomerically different starting materials give rise to stereoisomerically different products; a s. process is thus necessarily stereoselective, but not all stereoselective processes are s..

stereotactic, stereotaxic (ster′e-o-tak′tik, -tak′sik)
Relating to stereotaxis or stereotaxy.

stereotaxis (ster′e-o-tak′sis)
1. Three-dimensional arrangement. 2. Stereotropism, but applied more exactly where the organism as a whole, rather than a part only, reacts. 3. SYN: stereotaxy. [stereo- + G. taxis, orderly arrangement]

stereotaxy (ster′e-o-tak′se)
A precise method of identifying nonvisualized anatomic structures by use of three-dimensional coordinates; more frequently used for brain and spinal surgery. SYN: stereotactic surgery, stereotaxic surgery, stereotaxis (3) .

stereotropic (ster′e-o-trop′ik)
Relating to or exhibiting stereotropism.

stereotropism (ster′e-ot′ro-pizm)
Growth or movement of a plant or animal toward (positive s.) or away from (negative s.) a solid body, usually applied where a part of the organism rather than the whole reacts. [stereo- + G. tropos, a turning]

stereotypy (ster′e-o-ti-pe)
1. Maintenance of one attitude for a long period. 2. Constant repetition of certain meaningless gestures or movements, as in certain forms of schizophrenia. [stereo- + G. typos, impression, type] oral s. SYN: verbigeration.

steric (ster′ik, ster-)
Pertaining to stereochemistry. s. hindrance interference with or inhibition of a seemingly feasible reaction (usually synthetic) because the size of one or another reactant prevents approach to the required interatomic distance.

sterid (ster′id, ster-)
SYN: steroid (2) .

sterigma, pl .sterigmata (ste-rig′ma, -ma-ta)
A slender, pointed structure arising from a basidium upon which a basidiospore will develop. [G. s., a support]

sterile (ster′il)
Relating to or characterized by sterility. [L. sterilis, barren]

sterility (ste-ril′i-te)
1. In general, the incapability of fertilization or reproduction. See female s., male s.. 2. Condition of being aseptic, or free from all living microorganisms. [L. sterilitas] aspermatogenic s. s. due to a failure to produce living spermatozoa. dysspermatogenic s. male s. due to some abnormality in production of spermatozoa. female s. the inability of the female to conceive, due to inadequacy in structure or function of the genital organs. SYN: infecundity. male s. the inability of the male to fertilize the ovum; it may or may not be associated with impotence. normospermatogenic s. male s. due to some cause other than failure to produce live, normal spermatozoa, e.g., blockage of the seminiferous passages.

sterilization (ster′i-li-za′shun)
1. The act or process by which an individual is rendered incapable of fertilization or reproduction, as by vasectomy, partial salpingectomy, or castration. 2. The destruction of all microorganisms in or about an object, as by steam (flowing or pressurized), chemical agents (alcohol, phenol, heavy metals, ethylene oxide gas), high-velocity electron bombardment, heat, or ultraviolet light radiation. discontinuous s. SYN: fractional s.. fractional s. exposure to a temperature of 100°C (flowing steam) for a definite period, usually an hour, on each of several days; at each heating the developed bacteria are destroyed; spores, which are unaffected, germinate during the intervening periods and are subsequently destroyed. SYN: discontinuous s., intermittent s., tyndallization. intermittent s. SYN: fractional s..

sterilize (ster′i-liz)
To produce sterility.

sterilizer (ster′i-li-zer)
An apparatus for rendering objects sterile. glass bead s. a s. for endodontic equipment; the heat is transmitted to the instruments, absorbent points, or cotton pellets by means of glass beads. hot salt s. a s. for endodontic equipment in which table salt is heated in a container at 218–246°C; the dry heat is transmitted to root canal instruments, absorbent points, or cotton pellets for their rapid (5–10 seconds) sterilization.

Heinrich, U.S. physician, 1868–1918. See S. posture.

See sterno-.

sterna (ster′na)
Plural of sternum.

sternad (ster′nad)
In a direction toward the sternum.

sternal (ster′nal)
Relating to the sternum.


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