lamina densa

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Related to lamina densa: lamina propria, Lamina lucida, lamina rara


 [lam´ĭ-nah] (L.)
1. a thin, flat plate or stratum of a composite structure; called also layer.
basal lamina (lamina basa´lis) the layer of the basement membrane lying next to the basal surface of the adjoining cell layer composed of an electron-dense lamina densa and an electron-lucent lamina lucida.
lamina basila´ris the posterior wall of the cochlear duct, separating it from the scala tympani.
lamina choroidocapilla´ris the inner layer of the choroid, composed of a single-layered network of small capillaries.
lamina cribro´sa
2. (of ethmoid bone) the horizontal plate of ethmoid bone forming the roof of the nasal cavity, and perforated by many foramina for passage of olfactory nerves.
3. (of sclera) the perforated part of the sclera through which pass the axons of the retinal ganglion cells.
lamina den´sa an electron-dense layer of the basal lamina, consisting mainly of collagen fibrils and proteoglycans; it closely follows the plasma membrane of the basal aspect of the adjacent cell layer, from which it is separated by the lamina lucida (or the lamina rara in the renal glomerulus and pulmonary alveolus).
lamina du´ra a layer of the alveolar bone that is thin and particularly compact and appears as a line on dental x-rays. Called also bundle bone.
epithelial lamina the layer of ependymal cells covering the choroid plexus.
lamina fus´ca the pigmentary layer of the sclera.
lamina lu´cida an electron-dense layer of the basal lamina lying between the lamina densa and the adjoining cell layer; in the pulmonary alveolus and renal glomerulus it is divided into the internal and external laminae rarae.
lamina pro´pria
1. the connective tissue layer of mucous membrane.
2. the middle fibrous layer of the tympanic membrane.
lamina ra´ra
1. in the renal glomerulus and pulmonary alveolus, one of the layers of lamina lucida surrounding the lamina densa; the lamina rara externa is on the epithelial side and the lamina rara interna is on the endothelial side.
2. a term sometimes used as a synonym for lamina lucida.
reticular lamina a layer of the basement membrane, adjacent to the connective tissue, seen in some epithelia; it is of variable thickness and is composed of condensed connective tissue with a reticulum of collagen fibers.
Rexed's laminae an architectural scheme used to classify the structure of the spinal cord, based on the cytological features of the neurons in different regions of the gray substance. It consists of nine laminae (I–IX) that extend throughout the cord, roughly paralleling the dorsal and ventral columns of the gray substance, and a tenth region (lamina X) that surrounds the central canal and consists of the dorsal and ventral commissures and the central gelatinous substance.
spiral lamina (lamina spira´lis)
1. a double plate of bone winding spirally around the modiolus, dividing the spiral canal of the cochlea into the scala tympani and scala vestibuli.
2. a bony projection on the outer wall of the cochlea in the lower part of the first turn.
terminal lamina of hypothalamus the thin plate derived from the telencephalon, forming the anterior wall of the third ventricle of the cerebrum.
vertebral lamina (lamina of vertebral arch) either of the pair of broad plates of bone flaring out from the pedicles of the vertebral arches and fusing together at the midline to complete the dorsal part of the arch and provide a base for the spinous process of the vertebra.

lam·i·na den·'sa

1. the electron-dense layer of the basal lamina as seen under the electron microscope; it is composed mostly of type IV collagen.
See also: basement membrane.
2. the extraordinarily thick basal lamina of the renal glomerulus.
Synonym(s): basal lamina (2)

lamina densa

a layer of epithelial basal lamina that appears dark in electron micrographs.

lam·i·na den·sa

(lami-nă densă)
1. The electron-dense layer of the basal lamina as seen under the electron microscope.
2. The extraordinarily thick basal lamina of the renal glomerulus.
Synonym(s): basal lamina (2) .
References in periodicals archive ?
El primero de ellos consiste en la interferencia por parte de estos anticuerpos unidos al colageno tipo VII con las interacciones normales entre este colageno y sus ligandos localizados en la matriz extracelular, en la membrana basal o en la dermis papilar, lo cual debilita o bloquea las conexiones de las fibrillas de anclaje con la lamina densa o las placas de anclaje, produciendo finalmente una adherencia defectuosa entre la dermis y la lamina densa (57): el segundo mecanismo propuesto es la union de estos anticuerpos al dominio NC2 que desestabiliza las fibrillas de anclaje al interferir con la formacion de dimeros antiparalelos del colageno tipo VII (56): el tercer mecanismo es el dano tisular inflamatorio por activacion del complemento (58,59).
Daha sonra hasta serumlarinin lamina densa bileseni olan laminin [gamma]1 ile reaksiyon vermesi ile p200'un laminin [gamma]1 olabilecegi dusunulmus ve hastaligin anti-laminin [gamma]1 pemfigoid olarak isimlendirilmesi onerilmistir (60-62).
Immunelektron mikroskobik arastirmalar bu hastalardaki anti-BP180 IgG'nin lamina lusida alt kisminda lamina densa ile birlesimine yakin yerlesimde oldugu gostermistir; bu yerlesim bazal membranda BP180 distal hucre disi kismina uymaktadir (65).