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Medical Dictionary


spongy (spun′je)
Of spongelike texture or appearance. SYN: spongiform, spongioid.

spontaneous (spon-ta′ne-us)
Without apparent cause; said of disease processes or remissions. [L. spontaneus, voluntary, capricious]

spoon (spoon)
An instrument with a handle and a small bowl- or cup-shaped extremity. [A.S. spon, chip] cataract s. a small concave instrument for removing a cataractous lens. Daviel s. a small ovoid instrument for removing the remains of a cataract after discission. sharp s. an instrument with a small cup-shaped extremity having sharpened edges, used for scraping skin lesions. Volkmann s. a sharp s. for scraping away carious bone or other diseased tissue.

See sporo-.

sporadic (spo-rad′ik)
1. Denoting a temporal pattern of disease occurrence in an animal or human population in which the disease occurs only rarely and without regularity. See endemic, epidemic, enzootic, epizootic. 2. In the genetic context denotes a singleton or sport. Several quite different and disparate phenomena are covered by this term, including a new mutation; occult nonpaternity; the chance outcome for a recessive trait in two carrier parents with a small family; extreme variability in the expression of a gene; an environmental phenocopy; a multilocal genocopy, etc. No useful properties can be predicated of all members of this class; and the term is notionally useless. 3. Occurring irregularly, haphazardly. [G. sporadikos, scattered]

sporadin (spor′a-din)
Gamont stage of a gregarine parasite after it has lost its epimerite or mucron.

sporangiophore (spo-ran′je-o-for)
In fungi, a specialized hypha that bears a sporangium at its tip. [sporangium + G. phoros, bearing]

sporangium (spo-ran′je-um)
A saclike structure (a cell) within a fungus, in which asexual spores are borne by progressive cleavage. [L. fr. G. sporos, seed, + angeion, vessel]

spore (spor)
1. The asexual or sexual reproductive body of fungi or sporozoan protozoa. 2. A cell of a plant lower in organization than the seed-bearing spermatophytic plants. 3. A resistant form of certain species of bacteria. 4. The highly modified reproductive body of certain protozoa, as in the phyla Microspora and Myxozoa. [G. sporos, seed] black s. a degenerating malarial or other blood parasite in the body of the mosquito.

sporicidal (spor-i-si′dal)
Lethal to spores. [spori- + L. caedo, to kill]

sporicide (spor′i-sid)
An agent that kills spores.

sporidium, pl .sporidia (spo-rid′e-um, -a)
A protozoan spore; an embryonic protozoan organism. [Mod. L. dim., fr. G. sporos, seed]

sporo-, spori-, spor-
Seed, spore. [G. sporos]

sporoagglutination (spor′o-a-gloo-ti-na′shun)
A diagnostic method in relation to the mycoses, based upon the fact that the blood of patients with diseases caused by fungi contains specific agglutinins that cause clumping of the spores of these organisms.

sporoblast (spor′o-blast)
An early stage in the development of a sporocyst prior to differentiation of the sporozoites. SEE ALSO: oocyst, sporocyst (2) , pansporoblast. SYN: zygotomere. [sporo- + G. blastos, germ]

sporocyst (spor′o-sist)
1. A larval form of digenetic trematode (fluke) that develops in the body of its molluscan intermediate host, usually a snail; the s. forms a simple saclike structure with germinal cells that bud off internally and develop into other larval types that continue this process of larval multiplication (considered to be a form of polyembryony). SEE ALSO: miracidium, redia, cercaria. 2. A secondary cyst that develops within the oocyst of Coccidia, a group of sporozoans that includes many of the most important disease agents of domestic animals and fowl; the s. develops from a sporoblast and produces within itself one or several sporozoites, the infective agents for infection and multiplication in the next host. [sporo- + G. kystis, bladder]

Sporocystinea (spor′o-sis-tin′e-a)
In older classification schemes, a suborder of Coccidia in which the sporoblasts develop sporocysts. [sporo + G. kystis, bladder]

sporodochium (spo-ro-do′ke-um)
In fungi, a cushion-shaped stroma covered with conidiophores.

sporogenesis (spor-o-jen′e-sis)
SYN: sporogony. [sporo- + G. genesis, production]

sporogenous (spo-roj′e-nus)
Relating to or involved in sporogony.

sporogeny (spo-roj′e-ne)
SYN: sporogony.

sporogony (spo-rog′o-ne)
The formation of sporozoites in sporozoan protozoa, a process of asexual division within the sporoblast, which becomes the sporocyst within an oocyst; follows fusion of gametes (gametogony) and zygote (sporont) formation. SYN: sporogenesis, sporogeny. [sporo- + G. goneia, generation]

sporont (spor′ont)
The zygote stage within the oocyst wall in the life cycle of coccidia; gives rise to sporoblasts, which form sporocysts, within which the infective sporozoites are produced. [sporo- + G. on (ont-), being]

sporophore (spor′o-for)
Any specialized hyphas in fungi that give rise to spores. [sporo- + G. phoros, bearing]

sporoplasm (spor′o-plazm)
The protoplasm of a spore. [sporo- + G. plasma, thing formed]

sporotheca (spor′o-the′ka)
The envelope enclosing the minute needle-like spores of certain Sporozoea. [sporo- + G. theke, case]

Sporothrix (spor′o-thriks)
A genus of dimorphic imperfect fungi, including the species S. schenckii, an organism of worldwide distribution and the causative agent of sporotrichosis in humans and animals, which grows in soil or vegetation, especially in thorny bushes, and is acquired by humans when infected thorns are introduced into subcutaneous tissues; at 37°C it grows as a yeast and parasitizes tissues as a yeast. [Mod. L., fr. G. sporos, seed, + thrix, hair]

sporotrichosis (spor′o-tri-ko′sis)
A chronic cutaneous mycosis spread by way of the lymphatics and caused by inoculation of Sporothrix schenckii, typically rare in tissue sections but rapidly growing in cultures. Extracutaneous s. probably originates in the lung but disseminates to cause osteoarticular or other visceral disease. Chronic cavitary lung disease is another manifestation. SYN: Schenck disease.

Sporotrichum (spo-rot′ri-kum)
A genus of imperfect fungi (Hyphomycetes) that are usually common contaminants. [Mod. L. fr. G. sporos, seed, + thrix, hair]

sporozoan (spor-o-zo′an)
1. An individual organism of the class Sporozoea. SYN: sporozoon. 2. Relating to the Sporozoea.

Sporozoasida (spor′o-zo-as′i-da)
SYN: Sporozoea.

Sporozoea (spor-o-zo′e-a)
A large class of protozoans (phylum Apicomplexa, subkingdom Protozoa) consisting of obligatory parasites with simple spores lacking polar filaments; cilia and flagella are absent (except for microgametes, found in some groups), and locomotion is by undulation, gliding, or body flexion; sexuality, when present, is by syngamy, forming oocysts with infective sporozoites from sporogony. The class includes the gregarines and coccidia, the latter including many agents of human and animal disease, such as the plasmodia of malaria. SYN: Sporozoasida, Telosporea. [Mod. L., fr. G. sporos, seed, + zoon, animal]

sporozoite (spor-o-zo′it)
One of the minute elongated bodies resulting from the repeated division of the oocyst during sporogony. In the case of the malarial parasite, it is the form that is concentrated in the salivary glands and introduced into the blood by the bite of a mosquito; it enters the liver cells (exoerythrocytic cycle), whose progeny, the merozoites, infect the red blood cells to initiate clinical malaria. SYN: germinal rod, zoite, zygotoblast. [sporo- + G. zoon, animal]

sporozoon (spor-o-zo′on)
SYN: sporozoan (1) .

sport (sport)
An organism varying in whole or in part, without apparent reason, from others of its type; this variation may be transmitted to the descendants or the latter may revert to the original type. SYN: singleton (2) . [M.E. disporte, fr. O.Fr. desport, diversion]

sporular (spor′u-lar)
Relating to a spore or sporule.

sporulation (spor′oo-la′shun)
The process by which yeasts undergo meiosis, and the meiotic products are encased in spore coats.

sporule (spor′ool)
A spore;a small spore. [Mod. L. sporula; dim. of G. sporos, seed]

1. SYN: macula. 2. To lose a slight amount of blood through the vagina. acoustic spots macula of utricle, macula of saccule. Bitot spots small, circumscribed, lusterless, grayish white, foamy, greasy, triangular deposits on the bulbar conjunctiva adjacent to the cornea in the area of the palpebral fissure of both eyes; occurs in vitamin A deficiency. blind s. 1. SYN: physiologic scotoma. 2. SYN: mental scotoma. 3. SYN: optic disk. blood spots hemorrhagic graafian follicles seen in ovaries of mice, caused by injection of urine of pregnant women; a positive result in the now obsolete Aschheim-Zondek test for pregnancy. blue s. 1. SYN: macula cerulea. 2. SYN: mongolian s.. Brushfield spots light-colored condensations of the surface of the mid-iris; seen in Down syndrome. café au lait spots pigmented cutaneous lesions, ranging from light to dark brown, and due to an excess of melanosomes in the malpighian cells, rather than to an excess of melanocytes; café au lait spots are one of the major cutaneous manifestations of neurofibromatosis (von Recklinghausen disease), with type 1 (peripheral) neurofibromatosis, almost always 6 or more café-au-lait spots can be found with at least some exceeding 1.5 cm in diameter. These are often accompanied by frecklelike spots in the axilla. cherry-red s. the ophthalmoscopic appearance of the normal choroid beneath the fovea centralis, appearing as a red s. surrounded by white retinal edema in central artery closure or lipid infiltration in sphingolipidosis. SYN: Tay cherry-red s.. corneal s. SYN: macula corneae. cotton-wool spots SYN: cotton-wool patches, under patch. De Morgan spots SYN: senile hemangioma. Elschnig spots isolated choroidal bright yellow or red spots with black pigment flecks at their borders, seen ophthalmoscopically in advanced hypertensive retinopathy. flame spots hemorrhagic areas occurring in the nerve fiber layer of the retina. focal s. the site of bombardment by electrons and emission of x-rays from the anode of an x-ray tube. SEE ALSO: focal s. size. Fordyce spots a condition marked by the presence of numerous small, yellowish-white bodies or granules on the inner surface and vermilion border of the lips; histologically the lesions are ectopic sebaceous glands. SYN: Fordyce disease, Fordyce granules. Fuchs black s. an area of pigment proliferation in the macular region in degenerative myopia. hot s. a region in a gene in which there is a putatively high rate of mutation or recombination. hypnogenic s. a pressure-sensitive point on the body of certain susceptible persons, which, when pressed, causes the induction of sleep. Koplik spots small red spots on the buccal mucous membrane, in the center of each of which may be seen, in a strong light, a minute bluish white speck; they occur early in measles (morbilli), before the skin eruption, and are regarded as a pathognomonic sign of the disease. liver s. SYN: senile lentigo. Mariotte blind s. SYN: optic disk. milk spots 1. white plaques of hyalinized fibrous tissue situated in the epicardium overlying the right ventricle of the heart where it is not covered by lung; SYN: soldier's patches. 2. white macroscopic areas in the omentum, due to accumulation of macrophages and lymphocytes. SYN: tache laiteuse (1) . mongolian s. any of a number of dark-bluish or mulberry-colored rounded or oval spots on the sacral region due to the ectopic presence of scattered melanocytes in the dermis. These congenital lesions are frequent in black, native American, and Asian children from 2 to 12 years, after which time they gradually recede; they do not disappear on pressure and are sometimes mistaken for bruises from child abuse. SYN: blue s. (2) . mulberry spots the abdominal eruption in typhus fever. rose spots characteristic exanthema of typhoid fever; 10–20 small pink papules on the lower trunk lasting a few days and leaving hyperpigmentation. Roth spots a round white retina s. surrounded by hemorrhage in bacterial endocarditis, and in other retinal hemorrhagic conditions. saccular s. SYN: macula of saccule. Soemmerring s. SYN: macula of retina. spongy s. SYN: vascular zone. Tardieu spots SYN: Tardieu ecchymoses, under ecchymosis. Tay cherry-red s. SYN: cherry-red s.. temperature s. one of a number of definitely arranged spots on the skin sensitive to heat and cold, but not to ordinary pressure or pain stimuli. tendinous s. SYN: macula albida. Trousseau s. SYN: meningitic streak. utricular s. SYN: macula of utricle. white s. SYN: macula albida. yellow s. SYN: macula of retina.

Abbreviation for plural of species.

sprain (spran)
1. An injury to a ligament as a result of abnormal or excessive forces applied to a joint, but without dislocation or fracture. 2. To cause a s. of a joint.

spray (spra)
A jet of liquid in fine drops, coarser than a vapor; it is produced by forcing the liquid from the minute opening of an atomizer, mixing it with air.

spreader (spred′er)
1. An instrument used to distribute a substance over a surface or area. 2. A device for spacing or parting structures. gutta-percha s. an instrument used in dentistry for condensing gutta-percha laterally in a root canal. rib s. a retractor for widening the space between ribs in intrathoracic operations. root canal s. a tapered instrument utilized for condensing root filling materials laterally.

Otto G.K., German surgeon, 1852–1915. See S. deformity.

sprout (sprowt)
A structure resembling the s. of a plant. syncytial s. SYN: syncytial knot.

sprue (sproo)
1. Primary intestinal malabsorption with steatorrhea. SYN: cachexia aphthosa. 2. In dentistry, wax or metal used to form the aperture(s) for molten metal to flow into a mold to make a casting; also, the metal that later fills the s. hole(s). [D. spruw] celiac s. SYN: celiac disease. nontropical s. s. occurring in persons away from the tropics; usually called celiac disease; due to gluten-induced enteropathy. tropical s. s. occurring in the tropics, often associated with enteric infection and nutritional deficiency, and frequently complicated by folate deficiency with macrocytic anemia. SYN: tropical diarrhea.

sprue-former (sproo-for′mer)
The base to which the sprue (2) is attached while the wax pattern is being invested in a refractory investment in a casting flask; it is sometimes referred to as a crucible-former.

spud (spud)
A triangular knife used for removing foreign bodies from the cornea.

Spumavirinae (spoo′ma-vir′i-ne)
Formerly a subfamily of viruses (family Retroviridae) that includes the foamy viruses (agents) of primates and other mammals; they are now placed in the genus Spumavirus. In common with other retroviruses, they possess RNA-dependent DNA polymerases (reverse transcriptase). [L. spuma, foam]

Spumavirus (spoo′ma-vi-rus)
A virus genus encompassing a poorly characterized group of retroviruses that cause vacuolation (foaming) of cultured cells; usually cause persistent but silent infections in their natural hosts and no diseases caused by these agents have been identified.

spur (sper) [TA]
SYN: calcar. [A.S. spora] calcarine s. [TA] the lower of two elevations on the medial wall of the posterior horn of the lateral ventricle of the brain, caused by the depth of the calcarine sulcus. SYN: calcar avis [TA] , Haller unguis, hippocampus minor, minor hippocampus, Morand s., unguis avis. Fuchs s. epithelial outgrowth of the dilator muscle of the pupil about midway in the breadth of the sphincter; part of the insertion of the dilator muscle onto the iris sphincter. Grunert s. epithelial outgrowth of the dilator muscle of the pupil at the junction of the iris and the ciliary body; part of the origin of the iris dilator muscle. heel s. bony thickening of the flexor surface of the calcaneus associated with severe pain on standing. Michel s. epithelial outgrowth of the dilator muscle of the pupil at the peripheral border of the sphincter; part of the insertion of the dilator muscle onto the iris sphincter. Morand s. SYN: calcarine s.. scleral s. [TA] circular ridge of sclera on the internal aspect of the corneoscleral junction; on cross-section, it appears as a hook-like process deep to the scleral venous sinus; relatively rigid, it provides attachment (origin) of the meridional fibers of the ciliary body. SYN: calcar sclerae [TA] , scleral roll. vascular s. partial septum between vessels (arteries and veins) at the level of fusion or branching at acute angle. SEE ALSO: calcar (1) .

spurious (spoo′re-us)
False; not genuine. [L. spurius]

sputum, pl .sputa (spu′tum, -ta)
1. Expectorated matter, especially mucus or mucopurulent matter expectorated in diseases of the air passages. SEE ALSO: expectoration (1) . 2. An individual mass of such matter. [L. s., fr. spuo, pp. sputus, to spit] s. aerogenosum a green expectoration seen occasionally in jaundice, due to staining of the s. by bile pigments. SYN: green s.. globular s. SYN: nummular s.. green s. SYN: s. aerogenosum. nummular s. a thick, coherent mass expectorated in globular shape which does not run at the bottom of the cup but forms a discoid mass resembling a coin. SYN: globular s.. prune-juice s. a thin reddish expectoration, characteristic of necrosis of lung tissue, usually by infection; due to hemorrhage caused by destruction of the lung parenchyma; sometimes seen with lung tumors. SYN: prune-juice expectoration. rusty s. a reddish brown, blood-stained expectoration characteristic of lobar pneumonococcal pneumonia.

Abbreviation for subcutaneous.

squalamine lactate (skwal′a-men lak′tat)
An antiangiogenic, noncytotoxic drug used to treat solid tumors.

squalene (skwa′len)
A hexaisoprenoid (triterpenoid) hydrocarbon found in shark oil and in some plants; intermediate in the biosynthesis of cholesterol and other sterols and triterpenes. s. epoxidase an enzyme that catalyzes the conversion of s. to s. 2,3-oxide in the endoplasmic reticulum; a required step in order for cyclization to occur, resulting in the synthesis of the first sterol, lanosterol, in steroidogenesis; uses NADPH. s. synthase an enzyme that catalyzes the formation of s. from two molecules of farnesylpyrophosphate using NADPH and concomitant production of two molecules of pyrophosphate.

squama, pl .squamae (skwa′ma, skwa′me)
1. A thin plate of bone. 2. An epidermal scale. SYN: squame. SYN: scale (2) . [L. a scale] frontal s. SYN: squamous part of occipital bone. s. frontalis [TA] SYN: squamous part of frontal bone. s. occipitalis, occipital s. [TA] SYN: squamous part of occipital bone. temporal s. SYN: squamous part of temporal bone. s. temporalis SYN: squamous part of temporal bone.

squamatization (skwa′ma-ti-za′shun)
Transformation of other types of cells into squamous cells.

squame (skwam)
SYN: squama (2) .

Squama, squamous. [L. squama, a scale]

squamocellular (skwa-mo-sel′u-lar)
Relating to or having squamous epithelium.

squamocolumnar (skwa-mo-kol′um-nar)
Pertaining to the junction between a stratified squamous epithelial surface and one lined by columnar epithelium; e.g., the cardia of the stomach or anus.

squamofrontal (skwa′mo-fron′tal)
Relating to the squamous part of the frontal bone.


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