lamina cribrosa


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Related to lamina cribrosa: lamina cribrosa sclerae

lamina

 [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.

lamina cribrosa

1. The multiperforated plate of ethmoidal bone in the roof of the nose through which the fine fibres of the OLFACTORY NERVE pass.
2. The ring of perforations in the white of the eye, at the back of the globe, through which bundles of OPTIC NERVE fibres, and the central artery and vein of the RETINA, pass (lamina cribrosa sclerae).

cribriform plate 

This is a part of the sclera which is situated at the site of attachment of the optic nerve, 3 mm to the inner side of and just above the posterior pole of the eye. There, the sclera is a thin sieve-like membrane through which pass fibres of the optic nerve. Syn. lamina cribrosa (although this term also refers to the striated portion of the bulbar optic nerve which includes the cribriform plate). See myelinated nerve fibres.

lamina

pl. laminae [L.] a thin, flat plate or layer; a layer of a composite structure. Often used alone to mean a vertebral lamina.

lamina basilaris
the posterior wall of the cochlear duct, separating it from the scala tympani.
lamina choroidocapillaris
the inner layer of the choroid, composed of a single-layered network of small capillaries.
lamina cribrosa
1. fascia cribrosa.
2. (of ethmoid bone) the sieve-like transverse 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 to enter the optic nerve.
lamina densa, lamina dura
a layer of dental alveolar bone containing more than usual amounts of highly calcified cementing substance, associated with periodontal fibers in the bone; causes lines of increased radiodensity in dental radiographs—hence the name.
epithelial lamina
the layer of ependymal cells covering the choroid plexus.
lamina epithelialis mucosae
the layer of epithelial cells on the surface of the mucosa.
lamina femoralis
that part of the aponeurosis of the external abdominal oblique muscle which continues the lateral lip of the superficial inguinal ring onto the medial surface of the thigh in some species such as the horse.
lamina fibroreticularis
a thick layer of collagenous fibers projecting into the connective tissue space underlying the basement membrane.
lamina fusca
the loose connective tissue, deep, pigmentary layer of the sclera.
horny lamina
the laminae on the inside of the hoof which interdigitate with the sensitive laminae attached to the hoof corium.
lamina limitans
the layer of unmineralized matrix covering a bone surface that is not undergoing metabolic or structural change.
lamina lucida
the modified cell coat, appearing as a clear zone separating the basal lamina from the cell membrane.
lamina mucosae
includes laminae epithelialis mucosae (above), muscularis mucosae, propria mucosae (see below).
lamina muscularis mucosae
one or more smooth muscle layers, provides local mobility to the mucous membrane of organs; variable in occurrence.
omasal lamina
the leaves which line the internal aspect of the omasal wall; accounts for the colloquial name for the organ—bible; the religious connotation, if any, is unexplained.
lamina propria, lamina propria mucosae
1. the connective tissue layer of mucous membrane.
2. the middle fibrous layer of the tympanic membrane.
sensitive lamina
the laminae which interdigitate with the horny laminae of the hoof and which are made up of laminar corium plus a coat of not yet cornified epidermis.
spiral lamina, lamina spiralis
1. a double plate of bone winding spirally around the modiolus, dividing the spiral canal of the cochlea into the scala tympani and scali 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.
lamina terminalis grisea
thin plate forming the rostral wall of the third ventricle.
transverse lamina
separates the caudal part of the nasal cavity of the pig and dog into a ventral respiratory part and a dorsal olfactory part.
udder suspensory lamina
see udder suspensory apparatus.
vascular lamina
the vascular layer of the choroid of the eye; it lies between the suprachoroid and the choriocapillary layer.
vertebral lamina
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.
References in periodicals archive ?
Conventional risk factors for metastasis in retinoblastoma include extraocular extension or orbital invasion, massive uveal invasion, invasion of the optic nerve posterior to the lamina cribrosa or to the line of surgical transection, and anterior segment involvement.
Senesco" or the "Company") (AMEX: SNT) today announced that inhibiting the expression of its patent-pending gene, apoptosis eucaryotic Initiation Factor 5A ("Factor 5A"), has been shown to reduce apoptosis (cell death) in preclinical studies with human lamina cribrosa cells from the optic nerve head of human eyes.
A central retinal vein occlusion (CRVO) occurs when there is a blockage of blood flow within the central retinal vein; thrombosis is thought to occur at the lamina cribrosa.
Cerebrospinal fluid (CSF) cytology and bone marrow biopsy were advised for all patients with infiltration of iris, ciliary body, choroid, optic nerve lamina cribrosa, retrolaminar optic nerve, optic nerve to the line of transection, sclera, and extrascleral structures.