- Lamina
- A plate or layer. For example, the lamina arcus vertebrae, usually just called the lamina, are plates of bone in each vertebral body.
* * *- l. affixa [TA] that part of the medial ependymal wall of the lateral ventricle of the embryonic brain that in later development becomes adherent to the superior surface of the thalamus and thus comes to form the floor of the central part of the lateral ventricle; it covers the thalamostriate and choroidal veins.- alar l. of neural tube the dorsal division of the lateral walls of the neural tube in the embryo; it gives rise to neurons relaying afferent impulses to higher centers; in the adult such neurons compose the sensory nuclei of the spinal cord and brainstem. SYN: alar plate of neural tube, dorsolateral plate of neural tube, l. alaris, l. dorsalis, wing plate.- laminae albae cerebelli layers of white substance seen on section of the cerebellum. SYN: laminae medullares cerebelli.- anterior limiting l. [TA] the periphery of the cornea marking the termination of Descemet membrane and the anterior border of the trabecular meshwork; an important landmark in gonioscopy. SYN: l. limitans anterior [TA], anterior limiting ring, Schwalbe ring.- basal l. 1. an amorphous extracellular layer applied to the basal surface of epithelium and also investing muscle cells, fat cells, and Schwann cells; thought to be a selective filter and to serve both structural and morphogenetic functions. It is composed of a 20–100 nm network of file filaments called the l. densa which appears dense in the electron microscope, and on either side of this layer is a less dense layer called the l. rarae; SEE ALSO: basement membrane, l. densa. 2. SYN: l. densa.- basal l. of ciliary body [TA] the inner layer of the ciliary body, continuous with the basal layer of the choroid and supporting the pigment epithelium of the ciliary retina. SYN: l. basilaris corporis ciliaris [TA], basal layer of ciliary body, l. basalis corporis ciliaris.- basal l. of cochlear duct [TA] the membrane extending from the bony spiral membrane to the basilar crest of the cochlea; it forms the greater part of the floor of the cochlear duct separating the latter from the scala tympani and it supports the organ of Corti. SYN: l. basilaris ductus cochlearis [TA], basilar l., basilar membrane of cochlear duct, l. basilaris cochleae, membrana basilaris.- l. basalis choroideae [TA] the transparent, nearly structureless inner layer of the choroid in contact with the pigmented layer of the retina. SYN: basal l. of choroid [TA], basal layer of choroid [TA], Bruch membrane, Henle membrane, l. vitrea, vitreous lamella, vitreous membrane (3).- basal l. of neural tube the ventral division of the lateral walls of the neural tube in the embryo; it contains neuroblasts giving rise to somatic and visceral motor neurons. SYN: basal plate of neural tube, l. basalis, l. ventralis, ventral plate of neural tube.- boundary l. a basement membrane-like structure that invests muscle cells, fat cells, and Schwann cells. SEE ALSO: basement membrane, basal l..- capillary l. of choroid [TA] the internal or deep portion of the choroidea of the eye, composed of a very close capillary network. SYN: l. choroidocapillaris [TA], choriocapillaris, choriocapillary layer, entochoroidea, l. choriocapillaris, membrana choriocapillaris, Ruysch membrane.- l. choroidea SYN: epithelial l..- l. choroidea epithelialis SYN: epithelial l..- l. cribrosa of sclera [TA] the portion of the sclera through which pass the fibers of the optic nerve. SYN: l. cribrosa sclerae [TA], cribrous l., perforated layer of sclera.- l. of cricoid cartilage [TA] a quadrate plate forming the posterior part of the cricoid cartilage. It resembles the shield of a signet ring, the arch of the cricoid representing the remainder of the ring. SYN: l. cartilaginis cricoideae [TA].- l. densa 1. the electron-dense layer of the basal l. as seen in the electron microscope; SEE ALSO: basement membrane. 2. the extraordinarily thick basal l. of the renal glomerulus. SYN: basal l. (2).- dentogingival l. SYN: dental ledge.- elastic laminae of arteries 1) external : the layer of elastic connective tissue lying immediately outside the smooth muscle of the tunica media; 2) internal : a fenestrated layer of elastic tissue of the tunica intima. SYN: elastic layers of arteries, Henle fenestrated elastic membrane.- l. epiphysialis [TA] SYN: epiphysial plate.- epithelial l. the layer of modified ependymal cells that forms the inner layer of the tela choroidea, facing the ventricle. SYN: epithelial choroid layer, l. choroidea epithelialis, l. choroidea, l. epithelialis.- l. epithelialis SYN: epithelial l..- l. fibrocartilaginea interpubica SYN: interpubic disk.- l. fibroreticularis a layer of the basement membrane in continuity with associated connective tissue; it is often discontinuous and may be lacking entirely in some cases.- l. fusca sclerae [TA] SYN: suprachoroid l. of sclera.- l. interna ossium cranii SYN: vitreous table.- iridopupillary l. embryonic precursor of the anterior stroma of the iris that forms the inner (posterior or deep) wall of the primary anterior chamber of the eye. Its central portion becomes attenuated as the pupillary membrane (membrana pupillaris [NA]).- labiogingival l. a band of ectodermal epithelial cells growing into the mesenchyme of the embryonic jaws between the developing lip and the growing gingival elevation; it later opens to form the labiogingival groove.- lateral l. of cartilage of pharyngotympanic (auditory) tube [TA] the narrow lateral portion of the cartilaginous part of the pharyngotympanic (auditory) tube. SYN: l. lateralis cartilaginis tubae auditivae [TA], l. lateralis cartilaginis tubae auditoriae, lateral cartilaginous plate, lateral plate of cartilaginous auditory tube.- l. lateralis cartilaginis tubae auditivae [TA] SYN: lateral l. of cartilage of pharyngotympanic (auditory) tube.- l. lateralis cartilaginis tubae auditoriae lateral l. of cartilage of pharyngotympanic (auditory) tube.- lateral medullary l. [TA] of lentiform nucleus a thin, sharply defined layer of fibers separating the putamen from the globus pallidus. SYN: l. medullaris lateralis nuclei lentiformis [TA].- l. of lens one of a series of concentric layers composed of the lens fibers that make up the substance of the lens.- l. lucida the lightly staining layer of the basement membrane in contact with the plasmalemma of epithelial cells or other cells having an investment of basement membrane.- medial l. of cartilage of pharyngotympanic (auditory) tube [TA] the broad medial portion of the cartilaginous part of the pharyngotympanic (auditory) tube. SYN: l. medialis cartilaginis tubae auditivae [TA], l. medialis cartilaginis tubae auditoriae, medial cartilaginous plate, medial plate of cartilaginous auditory tube.- l. medialis cartilaginis tubae auditivae [TA] SYN: medial l. of cartilage of pharyngotympanic (auditory) tube.- l. medialis cartilaginis tubae auditoriae medial l. of cartilage of pharyngotympanic (auditory) tube, medial l. of cartilage of pharyngotympanic (auditory) tube.- medial medullary l. [TA] of lentiform nucleus a fiber layer separating the medial and lateral segments of the globus pallidus. SYN: l. medullaris medialis nuclei lentiformis [TA].- laminae medullares cerebelli SYN: laminae albae cerebelli.- l. medullaris lateralis nuclei lentiformis [TA] SYN: lateral medullary l. [TA] of lentiform nucleus.- l. medullaris medialis nuclei lentiformis [TA] SYN: medial medullary l. [TA] of lentiform nucleus.- medullary laminae of thalamus layers of myelinated fibers that appear on transverse sections of the thalamus; the l. medullaris lateralis [TA] (external medullary l. [TA]) marks the ventral and lateral borders of the thalamus and delimits it from the subthalamus and reticular nucleus of thalamus; the l. medullaris medialis [TA] (internal medullary l. [TA]) is interposed between the mediodorsal and ventral nuclei of the thalamus and encloses the intralaminar nuclei (centromedian, paracentral, and central lateral nuclei). SYN: laminae medullares thalami, medullary layers of thalamus.- l. membranacea cartilaginis tubae auditivae [TA] SYN: membranous l. of cartilage of pharyngotympanic (auditory) plate.- l. membranacea cartilaginis tubae auditoriae membranous l. of cartilage of pharyngotympanic (auditory) plate.- membranous l. of cartilage of pharyngotympanic (auditory) plate [TA] the connective tissue membrane that, with the lateral and medial laminae, completes the lateral and inferior walls of the cartilaginous part of the pharyngotympanic (auditory) tube. SYN: l. membranacea cartilaginis tubae auditivae [TA], l. membranacea cartilaginis tubae auditoriae, membranous layer.- l. of mesencephalic tectum the roofplate of the mesencephalon formed by the quadrigeminal bodies. SYN: l. tecti [TA], tectal plate [TA], tectum mesencephali [TA], l. quadrigemina, quadrigeminal l., quadrigeminal plate, tectum of midbrain.- l. of modiolus of cochlea [TA] a bony plate, the continuation of the modiolus and of the septum between the convolutions of the spiral canal of the cochlea extending upward toward the cupola, forming with the hamulus the helicotrema. SYN: l. modioli cochleae [TA], plate of modiolus.- l. muscularis mucosae SYN: muscularis mucosae.- nuclear l. a protein-rich layer lining the inner surface of the nuclear membrane in interphase cells.- osseous spiral l. [TA] a double plate of bone winding spirally around the modiolus dividing the spiral canal of the cochlea incompletely into two, scala tympani and scala vestibuli; between the two plates of this l., the fibers of the cochlear nerve reach the spiral organ (of Corti). SYN: l. spiralis ossea [TA], spiral plate.- l. parietalis [TA] SYN: parietal layer.- periclaustral l. SYN: external capsule.- l. perpendicularis [TA] SYN: perpendicular plate.- posterior limiting l. of cornea [TA] a transparent homogeneous acellular layer between the substantia propria and the endothelial layer of the cornea; considered to be a highly developed basement membrane. SYN: Descemet membrane, Duddell membrane, entocornea, hyaloid membrane, l. elastica posterior, l. limitans posterior corneae, membrana hyaloidea, membrana vitrea, posterior elastic layer, posterior limiting layer of cornea, tunica vitrea, vitreous membrane (1).- l. profunda musculi levatoris palpebrae superioris SYN: deep layer of levator palpebrae superioris.- l. propria [TA] the layer of connective tissue underlying the epithelium of a mucous membrane. SYN: l. propria mucosae.- l. propria mucosae SYN: l. propria.- l. rara the relatively electron-lucent layer on either side of the l. densa of the basement membrane.- reticular l. 1. a major component of the basement membrane, as seen by light microscopy; it consists largely of reticular fibers and ground substance. 2. the connective tissue plate in which the hair-bearing ends of the auditory sensory cells of the organ of Corti are embedded.- l. retrorectalis fasciae endopelvicae SYN: presacral fascia.- l. of Rexed a division of the gray matter of the spinal cord into nine laminae (I–IX) and a gray area around the central canal (area X) based on cytoarchitectural features; the dorsal (posterior) horn is composed of laminae I–VI, the intermediate zone of l. VII, and the ventral horn of laminae VIII and IX; general correlation of laminae with some of the major nuclei : I, posteromarginal nucleus; II, substantia gelatinosa; III and IV, nucleus proprius cornu dorsalis; V and VI, sometimes described as containing the spinal reticular formation; VII, Clarke nucleus, intermediolateral cell column; VIII, commissural nuclei, interneurons; IX, motor nuclei of ventral horn.- rostral l. a whitish line appearing on perfectly median sections of the brain as a thin bridge connecting the rostrum of the corpus callosum with the l. terminalis; the rostral l. contains no commissural fibers; instead, it corresponds to the line along which the pia mater reflects from the medial surface of one hemisphere to that of the other. SYN: l. rostralis, rostral layer, taeniola corporis callosi.- secondary spiral l. [TA] a ridge on the outer wall of the first turn of the cochlea opposite the spiral l.. SYN: l. spiralis secundaria [TA], secondary spiral plate.- l. of septum pellucidum one of the two thin layers of the transparent septum, which extend from the corpus callosum to the fornix; often separated from each other by a space, the cavity of septum pellucidum. SYN: l. septi pellucidi.- spinal l. II gelatinous substance.- l. spinalis II gelatinous substance.- l. spiralis secundaria [TA] SYN: secondary spiral l..- successional l. an ectodermal bud on the labial side of the dental l. that develops into a permanent tooth.- superficial l. SYN: superficial layer.- l. superficialis [TA] SYN: superficial layer.- l. superficialis musculi levatoris palpebrae superioris SYN: superficial layer of the levator palpebrae superioris.- suprachoroid l. of sclera [TA] an exceedingly delicate layer of loose, pigmented connective tissue between the inner surface of the sclera and the outer surface of the choroid, connecting them; formerly, the l. fusca and suprachoroid l. were considered as two adjacent layers. SYN: l. fusca sclerae [TA], brown layer, ectochoroidea, l. fusca of sclera, membrana fusca, suprachoroidea.- l. supraneuroporica that part of the choroid membrane of the third ventricle that forms the roof of the foramen of Monro.- l. terminalis of cerebrum [TA] a thin plate passing upward from the optic chiasm and forming the rostral boundary of the third ventricle; membrane closing the rostral neuropore. SYN: l. terminalis [TA], l. cinerea, terminal plate, velum terminale.- l. of thyroid cartilage [TA] one of the paired (right and left) thin quadrilateral plates of the thyroid cartilage that are joined anteriorly and form an open angle posteriorly. SYN: l. cartilaginis thyroideae [TA].- tragal l. [TA] a longitudinal curved plate of cartilage, the beginning of the cartilaginous portion of the external acoustic meatus. SYN: l. tragi [TA], l. of tragus.- vascular l. of choroid [TA] the external or superficial portion of the choroid of the eye containing the largest blood vessel s. SYN: l. vasculosa choroideae [TA], Haller vascular tissue, uvaeformis, vascular layer of choroid coat of eye, vascular layer.- l. of vertebral arch [TA] the flattened posterior portion of the vertebral arch extending between the pedicles and the midline, forming the dorsal wall of the vertebral foramen, and from the midline junction of which the spinous process extends. SYN: l. arcus vertebrae [TA], neurapophysis.- l. visceralis [TA] SYN: visceral layer.
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lam·i·na 'lam-ə-nə n, pl -nae -.nē, -.nī or -nas a thin plate or layer esp. of an anatomical part: asa) the part of the neural arch of a vertebra extending from the pedicle to the median lineb) one of the narrow thin parallel plates of soft vascular sensitive tissue that cover the pododerm of the walls of an animal's hoof and fit between corresponding horny laminae on the inside of the wall of the hoof* * *
n. (pl. laminae)a thin membrane or layer of tissue.* * *
lam·i·na (lamґĭ-nə) gen. and pl. laґminae [L.] [TA] layer: a thin flat plate or stratum of a composite structure. The term is often used alone to mean the lamina arcus vertebrae.Descriptions of anatomic structures are given on TA terms and include anglicized names of specific layers.
Medical dictionary. 2011.
