One of the layers of differentiated tissue, the aggregate of which forms any given structure, such as the retina or the skin. SEE ALSO: lamina, layer. [L. sterno, pp. stratus, to spread out, strew, ntr. of pp. as noun, s., a bed cover, layer]
- s. aculeatum obsolete term for s. spinosum.
- s. basale 1. the outermost layer of the endometrium which undergoes only minimal changes during the menstrual cycle; SYN: basal layer. 2. SYN: s. basale epidermidis.
- s. basale epidermidis the deepest layer of the epidermis, composed of dividing stem cells and anchoring cells. SYN: basal cell layer, columnar layer, germinative layer, palisade layer, s. basale (2), s. cylindricum, s. germinativum.
- s. circulare membranae tympani circular fibers deep to the radiate layer of the membrane that are more abundant near the periphery; not present in the pars flaccida. SYN: circular layer of tympanic membrane.
- s. circulare musculi detrusoris vesicae [TA] SYN: circular layer of detrusor (muscle) of urinary bladder.
- s. circulare tunicae muscularis intestini tenuis [TA] SYN: circular layer of muscle coat of small intestine.
- s. compactum the superficial layer of decidual tissue in the pregnant uterus, in which the interglandular tissue preponderates. SYN: compacta.
- s. corneum epidermidis the outer layer of the epidermis, consisting of several layers of flat keratinized non-nucleated cells. SYN: corneal layer of epidermis, horny layer of epidermis.
- s. corneum unguis the outer, horny layer of the nail. SYN: cornified layer of nail, horny layer of nail.
- s. cutaneum membranae tympani the thin layer of skin on the external surface of the tympanic membrane. SYN: cutaneous layer of tympanic membrane.
- s. cylindricum SYN: s. basale epidermidis.
- s. disjunctum the layer of partly detached cells on the free surface of the s. corneum, as seen in sections under the microscope; likely an artifact of fixation.
- s. fibrosum [TA] SYN: fibrous capsule.
- s. fibrosum panniculi adiposi telae subcutaneae [TA] SYN: fibrous layer in or on deep aspect of fatty layer of subcutaneous tissue.
- s. functionale the endometrium except for the s. basale; formerly believed to be lost during menstruation but now considered to be only partially disrupted.
- s. ganglionicum [TA] SYN: ganglionic layer.
- s. germinativum SYN: s. basale epidermidis.
- s. germinativum unguis the deeper layer of the nail that is continuous with the s. germinativum of the surrounding skin and from which the nail plate is continuously formed. SYN: germinative layer of nail.
- s. granulosum corticis cerebelli [TA] SYN: granular layer of cerebellum.
- s. granulosum folliculi ovarici vesiculosi the layer of small cells that forms the wall of an ovarian follicle. SYN: granular layer of a vesicular ovarian follicle, granulosa, membrana granulosa, s. granulosum ovarii.
- strata hippocampi [TA] SYN: layers of hippocampus, under layer.
- s. interolivare lemnisci the medial region of the medulla oblongata between the left and right olivary nucleus, traversed longitudinally by the left and right medial lemniscus, and transversely by the decussating olivocerebellar fibers.
- s. lemnisci a largely fibrous (hence whitish) layer of the superior colliculus separating the middle gray layer of superior colliculus from the deep gray layer of superior colliculus and containing, among others, fibers from the spinal and trigeminal lemnisci. SYN: fillet layer.
- s. limitans externum [TA] SYN: outer limiting layer.
- s. limitans internum [TA] SYN: inner limiting layer.
- s. longitudinale tunicae muscularis intestini tenuis [TA] SYN: longitudinal layer of muscle coat of small intestine.
- s. lucidum a layer of lightly staining corneocytes in the deepest level of the s. corneum; found primarily in the thick epidermis of the palmar and plantar skin. SYN: clear layer of epidermis.
- strata magnocellularia [TA] See lateral geniculate body.
- malpighian s. the living layer of the epidermis comprising the s. basale, s. spinosum, and s. granulosum. SYN: malpighian layer, malpighian rete.
- s. moleculare SYN: molecular layer.
- s. moleculare et substratum lacunosum [TA] SYN: lacunar-molecular layer. See layers of hippocampus, under layer.
- s. musculosum panniculi adiposi telae subcutaneae [TA] SYN: muscle layer in fatty layer of subcutaneous tissue.
- s. neuroepitheliale retinae SYN: neuroepithelial layer of retina.
- s. neurofibrarum [TA] SYN: layer of nerve fibers.
- s. nucleare externum [TA] SYN: outer nuclear layer.
- s. nucleare internum [TA] SYN: inner nuclear layer.
- s. opticum [TA] SYN: optic layer.
- s. oriens [TA] SYN: oriens layer. See layers of hippocampus, under layer.
- s. papillare corii the more superficial layer of the corium whose papillae interdigitate with the epidermis. SYN: corpus papillare, papillary layer.
- strata parvocellularia [TA] See lateral geniculate body.
- s. pigmenti corporis ciliaris the continuation of the pigment layer of the retina onto the posterior aspect of the ciliary body. SYN: pigmented layer of ciliary body.
- s. pigmenti iridis the double layer of pigmented epithelium on the posterior surface of the iris. SYN: pigmented layer of iris.
- s. plexiforme externum [TA] SYN: outer plexiform layer.
- s. plexiforme internum [TA] SYN: inner plexiform layer.
- s. radiatum [TA] SYN: radiant layer. See layers of hippocampus, under layer.
- s. radiatum membranae tympani the connective tissue layer of the tympanic membrane beneath the s. cutaneum, the fibers of which radiate from the manubrium of the malleus to the peripheral fibrocartilaginous ring of the membrane; absent from the pars flaccida. SYN: radiate layer of tympanic membrane.
- s. reticulare corii the thicker deep layer of the corium consisting of dense irregularly arranged connective tissue. SYN: reticular layer of corium, s. reticulare cutis, tunica propria corii.
- s. segmentorum externorum et internorum [TA] SYN: layer of inner and outer segments.
- s. spinosum epidermidis the layer of polyhedral cells in the epidermis; shrinkage artifacts and adhesion of these cells at their desmosomal junctions gives a spiny or prickly appearance. SYN: prickle cell layer, spinous layer.
- s. spongiosum the middle layer of the endometrium formed chiefly of dilated glandular structures; it is flanked by the compacta on the luminal side and the basalis on the myometrial side.
- s. subcutaneum SYN: subcutaneous tissue.
- s. zonale [TA] SYN: zonular layer.
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1) a layer of tissue <a deep \stratum of the skin>
2) a statistical subpopulation
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n.
a layer of tissue or cells, such as any of the layers of the epidermis of the skin (the stratum corneum is the outermost layer).
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stra·tum (stratґəm) (straґtəm) pl. straґta [L.] in anatomy, a sheetlike mass of substance; see also layer and lamina.Descriptions are given on TA terms, and include anglicized names of specific terms.
Medical dictionary. 2011.