Medical Dictionary

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stream (strem)
SYN: flumen. hair streams the curved lines along which the hairs are arranged on the head and various parts of the body, especially noticeable in the fetus. SYN: flumina pilorum.

streaming (strem′ing)
See ameboid movement.

streblodactyly (streb-lo-dak′ti-le)
SYN: camptodactyly. [G. streblos, twisted, + daktylos, finger]

Streeter
George L., U.S. embryologist, 1873–1948. See S. developmental horizon(s).

Streeter developmental horizon(s)
A term borrowed from geology and archeology by Streeter to define 23 developmental stages in young human embryos, from fertilization through the first 2 months; each horizon spanned 2–3 days and emphasized specific anatomic characteristics, to avoid discrepancies in the determination of age and body dimensions. [G.L. Streeter]

Streiff
Enrico Bernard, Swiss ophthalmologist, *1908. See Hallermann-S. syndrome, Hallermann-S.-François syndrome.

strength
1. The quality of being strong or powerful. 2. The degree of intensity. 3. The property of materials by which they endure the application of force without yielding or breaking. associative s. in psychology, the s. of a stimulus response linkage as measured by the frequency with which a stimulus elicits a particular response. See conditioning. biting s. SYN: force of mastication. compressive s. tensile s., except that the stress is in compression. fatigue s. the stress level below which a particular component will survive an indefinite number of load cycles (typically about 50% of the ultimate s. of the component). ionic s. (I) symbolized as Γ/2 or I and set equal to 0.5Σmizi2, where mi equals the molar concentration and zi the charge of each ion present in solution; if molar concentrations (ci) are used instead of molality (and the solution is dilute), then I = 0.5(1/ρo)Σcizi2 where ρo is the density of the solvent; a number of biochemically important events ( e.g., protein solubility and rates of enzyme action) vary with the ionic s. of a solution. tensile s. the maximum tensile stress or load that a material is capable of sustaining; usually expressed in pounds per square inch. ultimate s. the maximum stress achieved prior to failure of a component on a single application of the load. yield s. the amount of stress at which a permanent (plastic) deformation in a component becomes measurable (usually taken as 0.2% permanent strain).

strephosymbolia (stref′o-sim-bo′le-a)
1. Generally, the perception of objects reversed as if in a mirror. 2. Specifically, difficulty in distinguishing written or printed letters that extend in opposite directions but are otherwise similar, such as p and d, or related kinds of mirror reversal. [G. strepho, to turn, + symbolon, a mark or sign]

strepitus (strep′i-tus)
Rarely used term for a noise, usually an auscultatory sound. [L.]

streptavidin (strep-ta-vi′din)
A bacterial protein used as a probe in immunologic assays because of its strong affinity and specificity for biotin; s. is used as a bridge to link a chromogen to a biotinylated substrate specific for the substance of interest. [streptococcus + avidin]

strepticemia (strep-ti-se′me-a)
Obsolete term for streptococcemia.

streptidine (strep′ti-den)
An aglycone component of streptomycin.

strepto-
Curved or twisted (usually relating to organisms thus described). [G. streptos, twisted, fr. strepho, to twist]

Streptobacillus (strep-to-ba-sil′us)
A genus of nonmotile, non–spore-forming, aerobic to facultatively anaerobic bacteria (family Bacteroidaceae) containing Gram-negative, pleomorphic cells that vary from short rods to long, interwoven filaments that have a tendency to fragment into chains of bacillary and coccobacillary elements. These organisms can be pathogenic for rats, mice, and other mammals. The type species is S. moniliformis. [strepto- + bacillus] S. moniliformis a bacterial species commonly found as an inhabitant of the nasopharynx of rats; it occurs as the etiologic agent of an epizootic septic polyarthritis in mice and of one type of rat-bite fever; it is the type species of the genus S..

streptobiosamine (strep′to-bi-o′sa-men)
A methylamino disaccharide (streptose + N-methyl-l-glucosamine), with the oxygen link between C-2 of streptose and C-1 of the glucosamine; with streptidine, it forms streptomycin.

streptobiose (strep-to-bi′os)
Old term for streptose.

streptocerciasis (strep′to-ser-ki′a-sis)
Infection of humans and higher primates with the nematode Mansonella streptocerca.

streptococcal (strep′to-kok′al)
Relating to or caused by any organism of the genus Streptococcus.

streptococcemia (strep′to-kok-se′-me-a)
The presence of streptococci in the blood. SYN: streptosepticemia. [streptococcus + G. haima, blood]

streptococci (strep′to-kok′si)
Plural of streptococcus.

streptococcic (strep′to-kok′sik)
Relating to or caused by any organism of the genus Streptococcus.

streptococcosis (strep′to-ko-ko′sis)
Any streptococcal infection.

Streptococcus (strep-to-kok′us)
A genus of nonmotile (with few exceptions), nonsporeforming, aerobic to facultatively anaerobic bacteria (family Lactobacillaceae) containing Gram-positive, spherical or ovoid cells that occur in pairs or short or long chains. Dextrorotatory lactic acid is the main product of carbohydrate fermentation. These organisms occur regularly in the mouth and intestines of humans and other animals, in dairy and other food products, and in fermenting plant juices. Some species are pathogenic. The type species is S. pyogenes. [strepto- + G. kokkos, berry (coccus)] S. agalactiae a species found in the milk and tissues from udders of cows with mastitis; also reported to be associated with a variety of human infections, especially those of the urogenital tract. S. anginosus an α-hemolytic species of bacteria found in the human throat, sinuses, abscesses, vagina, skin, and feces; this organism is a common cause of isolated liver abscesses. S. bovis a bacterial species found in the bovine alimentary tract; this organism may also be found in blood and heart lesions in cases of subacute endocarditis. S. constellatus an α-hemolytic species of bacteria found in tonsils, purulent pleurisy, appendix, the nose, throat, and gums, and infrequently on the skin and in the vagina. S. durans a bacterial species found in dried milk powder and in the intestines of humans and other animals. S. faecalis SYN: Enterococcus faecalis. S. intermedius one of a heterogenous collection of streptococci, generally found in the mouth or upper respiratory tract; classification is generally established by fermentation patterns, analysis of the sugar composition of the cell wall, and use of sugar production patterns. SYN: Peptostreptococcus intermedius. S. lactis a bacterial species found commonly as a contaminant in milk and dairy products; a common cause of the souring and coagulation of milk; some strains produce nisin, a powerful antibiotic that inhibits the growth of many other Gram-positive organisms. S. milleri a term used to refer to the S. intermedius group, which contains three distinct streptococcal species including S. intermedius, S. constellatus, and S. anginosus. These bacteria are found in the human oral cavity and have been associated with a variety of infections including bacteremia; endocarditis; and CNS, oral, and thoracic infections. S. mitis a bacterial species found in the human mouth, throat, and nasopharynx; ordinarily, it is not considered to be pathogenic, but this organism may be recovered from ulcerated teeth and sinuses and from blood and heart lesions in cases of subacute endocarditis. S. morbillorum SYN: Peptostreptococcus morbillorum. S. mutans a bacterial species associated with the production of dental caries in humans and in some other animals and with subacute endocarditis. S. pneumoniae a species of Gram-positive, lancet-shaped cocci and diplococci frequently occurring in chains; cells are readily lysed by bile salts. Virulent forms are enclosed in type-specific polysaccharide capsules, the basis for an effective vaccine. Normal inhabitants of the respiratory tract, and the most common cause of lobar pneumonia, they are the most common causative agents of meningitis, and pneumonia worldwide, and also cause sinusitis, and other infections. It is the type species of the former genus Diplococcus. SYN: Fraenkel pneumococcus, pneumococcus, pneumonococcus. S. pyogenes a bacterial species found in the human mouth, throat, and respiratory tract and in inflammatory exudates, the bloodstream, and cellulitic lesions in human diseases; it is sometimes found in the udders of cows and in dust from sickrooms, hospital wards, schools, theaters, and other public places; it causes the formation of pus, fatal septicemia, and necrotizing fascitis and myositis. There is also a specific somatic antigen (M protein) for each of the approximately 85 types. It is the type species of the genus S.. S. salivarius a bacterial species found in the human mouth, throat, and nasopharynx, and associated with dental disease. S. sanguis a bacterial species originally found in the so-called vegetation on heart valves from cases of subacute bacterial endocarditis; occasionally found in infected sinuses and teeth and in house dust. S. viridans a name applied not to a distinct species but rather to the group of α-hemolytic streptococci as a whole; viridans streptococci have been isolated from the mouth and intestines of humans, the intestines of horses, the milk and feces of cows, and milk products. SYN: viridans streptococci.

streptococcus, pl .streptococci (strep′to-kok′us, -kok′si)
A term used to refer to any member of the genus S.. group A streptococci (GAS) a common bacteria that is the cause of strep throat, scarlet fever, impetigo, cellulitis-erysipelas, rheumatic fever, acute glomerular nephritis, endocarditis, and group A streptococcal necrotizing fasciitis. The prototype is S. pyogenes. group B streptococci a leading cause of a form of neonatal sepsis that has a 10–20% mortality rate and leaves a large number of survivors with brain damage; also a leading cause of meningitis. hemolytic streptococci SYN: β-hemolytic streptococci. α-hemolytic streptococci streptococci that form a green variety of reduced hemoglobin in the area of the colony on a blood agar medium. SEE ALSO: S. viridans. β-hemolytic streptococci those that produce active hemolysins (O and S) which cause a zone of clear hemolysis on the blood agar medium in the area of the colony; β-hemolytic streptococci are divided into groups (A to O) on the basis of cell wall C carbohydrate (see Lancefield classification); Group A (in the strains pathogenic for man) comprises more than 50 types (designated by Arabic numerals) determined by cell wall M protein, which seems to be associated closely with virulence and is produced chiefly by strains with matt or mucoid colonies, in contrast to nonvirulent, glossy colony-producing strains; other surface protein antigens such as R and T (T substance), and the nucleoprotein fraction (P substance) seem to be of less importance. The more than 20 extracellular substances elaborated by strains of β-hemolytic streptococci include erythrogenic toxin (elaborated only by lysogenic strains), deoxyribonuclease (streptodornase), hemolysins (streptolysins O and S), hyaluronidase, and streptokinase. SYN: hemolytic streptococci. viridans streptococci SYN: S. viridans.

streptodornase (SD) (strep-to-dor′nas)
A “dornase” (deoxyribonuclease) obtained from streptococci; used with streptokinase to facilitate drainage in septic surgical conditions.

streptofuranose (strep-to-foor′a-nos)
SYN: streptose.

streptokinase (SK) (strep-to-ki′nas)
An extracellular metalloenzyme from hemolytic streptococci that cleaves plasminogen, producing plasmin, which causes the liquefaction of fibrin (same activity as staphylokinase and urokinase); thus, used in the removal of clots. SYN: plasminokinase, streptococcal fibrinolysin.

streptokinase-streptodornase
A purified mixture containing streptokinase, streptodornase, and other proteolytic enzymes; used by topical application or by injection into body cavities to remove clotted blood and fibrinous and purulent accumulations of exudate; thus, used in the removal of clots.

streptolysin (strep-tol′i-sin)
A hemolysin produced by streptococci. s. O a hemolysin that is produced by β-hemolytic streptococci and is hemolytically active only in the reduced state; anti-s. O produced during infection is of diagnostic significance.

Streptomyces (strep-to-mi′sez)
A genus of nonmotile, aerobic, Gram-positive bacteria (family Streptomycetaceae) that grow in the form of a many-branched mycelium; conidia are produced in chains on aerial hyphae. These organisms (several hundred species in the genus) are predominantly saprophytic soil forms; some are parasitic on plants or animals; many produce antibiotics. The type species is S. albus. [strepto- + G. mykes, fungus] S. albus a bacterial species found in dust, soil, grains, and straw; some strains produce actinomycetin; others produce thiolutin or endomycin; it is the type species of the genus S.. S. gibsonii a bacterial species found in human infections. SYN: Nocardia gibsonii. S. somaliensis a bacterial species that causes Bouffardi white mycetoma.

Streptomycetaceae (strep′to-mi-se-ta′se-e)
A family of aerobic Gram-positive bacteria (order Actinomycetales) that produce a vegetative mycelium which does not fragment into bacillary or coccoid forms; they produce conidia which are borne on sporophores. These organisms occur primarily in the soil; some are thermophiles found in rotting manure, a few are parasitic, and many produce antibiotics. The type genus is Streptomyces.

streptomycete (strep′to-mi′set)
A term used to refer to a member of the genus Streptomyces; it is sometimes improperly used to refer to any member of the family Streptomycetaceae.

streptomycin (strep-to-mi′sin)
An antibiotic agent obtained from Streptomyces griseus that is active against the tubercle bacillus and a large number of Gram-positive and Gram-negative bacteria; also used in the form of dihydrostreptomycin (aldehyde of s. reduced to CH2OH). It is a glucoside and contains streptidine and streptobiosamine linked by an oxygen bridge between C-4 of the inositol residue and C-1 of the streptose residue; s. B has a mannose residue attached to the glucosamine and is a natural product, with less activity than s. A. It is used virtually exclusively in the treatment of tuberculosis; toxicity includes eighth cranial nerve damage leading to deafness and/or vestibular dysfunction. SYN: s. A.

streptomycin A
SYN: streptomycin.

streptomycosis (strep′to-mi-ko′sis)
Old term for streptococcemia. [strepto- + G. mykes, fungus, + -osis, condition]

streptonivicin (strep′to-ni-vi′sin)
SYN: novobiocin.

streptose (strep′tos)
An unusual l-pentose that is a component of streptobiosamine, hence of streptomycin. SYN: streptofuranose.

streptosepticemia (strep′to-sep-ti-se′me-a)
SYN: streptococcemia.

streptothrichosis (strep′to-thri-ko′sis)
SYN: dermatophilosis.

streptotrichiasis (strep′to-tri-ki′a-sis)
SYN: dermatophilosis.

streptotrichosis (strep′to-tri-ko′sis)
SYN: dermatophilosis.

streptozocin (strep-to-zo′sin)
An antineoplastic agent used in the treatment of metastatic islet-cell carcinoma of the pancreas. SYN: streptozotocin.

streptozotocin (strep′to-zo-toks′in)
SYN: streptozocin.

stress (stres)
1. Reactions of the body to forces of a deleterious nature, infections, and various abnormal states that tend to disturb its normal physiologic equilibrium (homeostasis). 2. In dentistry, the forces set up in teeth, their supporting structures, and structures restoring or replacing teeth as a result of the force of mastication. 3. The force or pressure applied or exerted between portions of a body or bodies, generally expressed in pounds per square inch. 4. In rheology, the force in a material transmitted per unit area to adjacent layers. 5. In psychology, a physical or psychological stimulus such as very high heat, public criticism, or another noxious agent or experience which, when impinging upon certain individuals, produces psychological strain or disequilibrium. [L. strictus, tight, fr. stringo, to draw together] life s. events or experiences that produce severe strain, e.g., failure on the job, marital separation, loss of a love object. shear s. the force acting in shear flow expressed per unit area; units in the CGS system: dynes/cm2. tensile s. a s. acting on a body per unit cross-sectional area so as to elongate the body. yield s. the critical s. that must be applied to a material before it begins to flow, as in a Bingham plastic.

stress breaker
A device that relieves the abutment teeth, to which a fixed or removable partial denture is attached, of all or part of the forces generated by occlusal function.

stress riser
A mechanical defect, such as a hole, in bone or other materials, that concentrates stress in the area and increases the risk of failure of the bone or material at that site.

stress shielding
Osteopenia occurring in bone as the result of removal of normal stress from the bone by an implant.

stretcher (stre′cher)
1. A litter, usually a sheet of canvas stretched to a frame with four handles, used for transporting the sick or injured. 2. A cart with four wheels and a flat top for the transportation of patients, usually within hospitals. [A.S. streccan, to stretch]

stria, gen. and pl. striae (stri′a, stri′e)
1. A stripe, band, streak, or line, distinguished by color, texture, depression, or elevation from the tissue in which it is found. SYN: striation (1) . 2. SYN: striae cutis distensae. [L. channel, furrow] acoustic striae SYN: medullary striae of fourth ventricle. anterior acoustic s. [TA] these axons originate in the ventral cochlear nucleus, cross the midline as part of the trapezoid body, join the lateral lemniscus, and terminate largely in the superior olivary complex. SYN: s. cochlearis anterior [TA] , ventral acoustic s. [TA] . striae atrophicae SYN: striae cutis distensae. auditory striae SYN: medullary striae of fourth ventricle. brown striae SYN: Retzius striae. striae ciliares shallow radial grooves on the surface of the orbiculus ciliaris extending from the teeth of the ora serrata and leading into the valleys between the ciliary processes. s. cochlearis anterior [TA] SYN: anterior acoustic s.. s. cochlearis intermedia [TA] SYN: intermediate acoustic s.. s. cochlearis posterior [TA] SYN: posterior acoustic s.. striae cutis distensae bands of thin wrinkled skin, initially red but becoming purple and white, which occur commonly on the abdomen, buttocks, and thighs at puberty and/or during and following pregnancy, and result from atrophy of the dermis and overextension of the skin; also associated with ascites and Cushing syndrome. SYN: atrophoderma striatum, lineae atrophicae, linear atrophy, stretch marks, s. (2) , striae atrophicae, striate atrophy of skin, traction atrophy. diagonalis s. See Broca diagonal band. s. diagonalis [TA] SYN: Broca diagonal band. s. externa medullae renalis [TA] SYN: outer stripes of renal medulla, under stripe. s. fornicis SYN: medullary s. of thalamus. Gennari s. SYN: line of Gennari. striae gravidarum striae cutis distensae related to pregnancy. intermediate acoustic s. [TA] these axons arise in the cochlear nuclei; some fibers cross adjacent to the trapezoid body, others ascend on the ipsilateral side; they terminate in periolivary nuclei and nuclei of the lateral lemniscus; may function to modulate activity in the olivocochlear tract. SYN: s. cochlearis intermedia [TA] . s. of internal granular layer [TA] See Baillarger lines, under line. s. of internal pyramidal layer [TA] See Baillarger lines, under line. s. interna medullae renalis [TA] SYN: inner stripes of renal medulla, under stripe. Knapp striae SYN: angioid streaks, under streak. s. laminae granularis internae [TA] SYN: Baillarger lines, under line. s. laminae molecularis [TA] SYN: band of Kaes-Bechterew. s. laminae pyramidalis internae [TA] SYN: Baillarger lines, under line. striae lancisi the lateral longitudinal s. and the medial longitudinal s.. Langhans s. fibrinoid that accumulates on the chorionic plate between the bases of placental villi during the first half of pregnancy. lateral longitudinal s. [TA] a thin longitudinal band of nerve fibers accompanied by gray matter, near each outer edge of the upper surface of the corpus callosum under cover of the cingulate gyrus. SYN: s. longitudinalis lateralis [TA] , s. tecta, tectal s.. s. longitudinalis lateralis [TA] SYN: lateral longitudinal s.. s. longitudinalis medialis [TA] SYN: medial longitudinal s.. s. mallearis [TA] SYN: malleolar s.. malleolar s. [TA] a bright line seen through the membrana tympani, produced by the attachment of the manubrium of the malleus. SYN: s. mallearis [TA] , mallear stripe. medial longitudinal s. a thin longitudinal band of nerve fibers accompanied by gray matter, running along the surface of the corpus callosum on either side of the median line. Together with the lateral longitudinal s. it forms part of a thin layer of gray matter on the dorsal surface of the corpus callosum, the indusium griseum, a rudimentary component of the hippocampus. SYN: s. longitudinalis medialis [TA] . striae medullares ventriculi quarti [TA] SYN: medullary striae of fourth ventricle. s. medullaris thalami [TA] SYN: medullary s. of thalamus. medullary striae of fourth ventricle [TA] slender fascicles of fibers extending transversely below the ependymal floor of the ventricle from the median sulcus to enter the inferior cerebellar peduncle. They arise from the arcuate nuclei on the ventral surface of the medullary pyramid. SYN: striae medullares ventriculi quarti [TA] , acoustic striae, auditory striae, Bergmann cords, medullary teniae, taeniae acusticae. medullary s. of thalamus [TA] a narrow, compact fiber bundle that extends along the line of attachment of the roof of the third ventricle to the thalamus on each side and terminates posteriorly in the habenular nucleus. It is composed of fibers originating in the septal area, the anterior perforated substance, the lateral preoptic nucleus, and the medial segment of the globus pallidus. SYN: s. medullaris thalami [TA] , s. fornicis, s. ventriculi tertii. s. of molecular layer [TA] SYN: band of Kaes-Bechterew. s. nasi transversa a single deep horizontal groove at the level of the alae, with no associated defects. SYN: transverse nasal groove. Nitabuch s. SYN: Nitabuch membrane. s. occipitalis [TA] SYN: line of Gennari. striae olfactoriae [TA] SYN: olfactory striae. olfactory striae [TA] three distinct fiber bands (s. medialis, s. intermedia, s. lateralis) that caudally extend the olfactory tract beyond its attachment to the olfactory trigone. The medial olfactory s. [TA] (s. olfactoria medialis [TA]) curves dorsally into the tenia tecta; the intermediate, often barely visible, extends straight back and terminates in the olfactory tubercle; the lateral olfactory s. [TA] (s. olfactoria lateralis [TA], the largest of the three, passes along the lateral side of the olfactory tubercle, curving laterally as far as the limen insulae, then sharply medially to reach the uncus of the parahippocampal gyrus where it terminates in the plexiform layer of the olfactory cortex. SEE ALSO: medial longitudinal s.. SYN: striae olfactoriae [TA] , olfactory roots. striae parallelae SYN: Retzius striae. posterior acoustic s. [TA] these axons originate from the dorsal cochlear nucleus, cross the midline dorsal to the trapezoid body, and join the lateral lemniscus; some fibers may terminate in the superior olivary nucleus but most pass directly to the inferior colliculus or synapse in the nuclei of the lateral lemniscus enroute. SYN: s. cochlearis posterior [TA] . striae retinae concentric lines on the surface of an abnormal retina. SYN: Paton lines. Retzius striae dark concentric lines crossing the enamel prisms of the teeth, seen in axial cross sections of the enamel. SYN: brown striae, striae parallelae. Rohr s. layer of fibrinoid in the intervillous spaces of the placenta. s. spinosa a faint groove occasionally caused by the chorda tympani nerve on the spine of the sphenoid. SYN: Lucas groove, sulcus spinosus. s. tecta SYN: lateral longitudinal s.. tectal s. SYN: lateral longitudinal s.. terminal s. [TA] a slender, compact fiber bundle that connects the amygdala (amygdaloid body) with the hypothalamus and other basal forebrain regions. Originating from the amygdala, the bundle passes first caudalward in the roof of the temporal horn of the lateral ventricle; it follows the medial side of the caudate nucleus forward in the floor of the ventricle's central part (or body) until it reaches the interventricular foramen, in the posterior wall of which it curves steeply down to enter the hypothalamus, with fibers passing both rostral and caudal to the anterior commissure. Coursing caudalward in the medial part of the hypothalamus, the bundle terminates in the anterior and ventromedial hypothalamic nuclei. SYN: s. terminalis [TA] , Foville fasciculus, Tarin tenia, tenia semicircularis. s. terminalis [TA] SYN: terminal s.. s. vascularis of cochlear duct [TA] the stratified epithelium lining the upper part of the ligamentum spirale cochleae; it is penetrated by capillaries and is believed to be the site of production of endolymph. SYN: s. vascularis ductus cochlearis [TA] , psalterial cord, vascular stripe. s. vascularis ductus cochlearis [TA] SYN: s. vascularis of cochlear duct. ventral acoustic s. [TA] SYN: anterior acoustic s.. s. ventriculi tertii SYN: medullary s. of thalamus. Wickham striae fine whitish lines, having a network arrangement, on the surface of lichen planus papules. striae of Zahn SYN: lines of Zahn, under line.

striatal (stri′a-tal)
Relating to the corpus striatum.

striate (stri′at)
Striped; marked by striae. [L. striatus, furrowed]

striation (stri-a′shun)
1. SYN: stria (1) . 2. A striate appearance. 3. The act of streaking or making striae. basal striations the vertical infranuclear striations due to the infolded plasma membrane and mitochondria; they are seen in kidney tubules and certain intralobular salivary ducts. tabby cat s. SYN: tigroid s.. tigroid s. linear whitish or yellowish markings on the fatty degenerated heart muscle. SYN: tabby cat s..

striatonigral (stri-a-to-ni′gral)
Referring to the efferent connection of the striatum with the substantia nigra.

striatum (stri-a′tum) [TA]
Collective name for the caudate nucleus and putamen which together with the globus pallidus or pallidum form the striate body. SYN: neostriatum&star. [L. neut. of striatus, furrowed] dorsal s. [TA] those portions of the caudate nucleus and especially the putamen located generally dorsal to a plane representing the anterior commissure; also called the dorsal basal ganglia; may function in motor activities with cognitive origins. SYN: s. dorsale [TA] . s. dorsale [TA] SYN: dorsal s.. ventral s. [TA] those portions of the s. located generally ventral to a plane representing the anterior commissure; includes the nucleus accumbens and some nuclei of the olfactory tubercle; may function in motor activities with emotional or motivational origins. SYN: s. ventrale [TA] . s. ventrale [TA] SYN: ventral s..

stricture (strik′choor)
A circumscribed narrowing or stenosis of a hollow structure, usually consisting of cicatricial contracture or deposition of abnormal tissue. [L. strictura, fr. stringo, pp. strictus, to draw tight, bind] anastomotic s. narrowing, usually by scarring, of an anastomotic suture line. anular s. a ringlike constriction encircling the wall of a canal. bridle s. narrowing of a canal by a band of tissue stretching across part of its lumen. contractile s. SYN: recurrent s.. functional s. SYN: spasmodic s.. organic s. a s. due to the presence of cicatricial or other new tissue, not spasmodic. SYN: permanent s.. permanent s. SYN: organic s.. recurrent s. a s. due to the presence of contractile tissue which may be dilated but soon returns. SYN: contractile s.. spasmodic s. a s. due to localized spasm of muscular fibers in the wall of the canal. SYN: functional s., temporary s.. temporary s. SYN: spasmodic s.. urethral s. a stenosing lesion of the urethra, due usually to inflammation or to iatrogenic instrumentation and resulting in reduction of urethral caliber which may be focal or may involve virtually the entire length of the urethra.

stricturoplasty (strik′chur-plas′te)
Surgical procedure for widening a structured segment of intestine that involves incision and closure in opposing directions. [stricture + G. plastos, formed]

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