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.
References in periodicals archive ?
[10] Optic nerve invasion beyond lamina cribrosa in Retinoblastoma is associated with greater metastatic risk.
The Lamina Cribrosa as a Potential Choke Point for Glymphatic Flow between the Optic Nerve and Retina.
LOXL1 deficiency in the lamina cribrosa as candidate susceptibility factor for a pseudoexfoliation-specific risk of glaucoma.
Brain tomography conducted in the emergency department and orbital magnetic resonance imaging (MRI) examination requested by ophthalmology showed no pathology other than sporadic hemorrhages in the vitreous and irregularity at the lamina cribrosa level consistent with right optic nerve avulsion.
This decrease in IOP is associated with changes in several ocular factors such as shortening of axial eye length (AEL), change in lamina cribrosa position, and increase in ocular blood flow [1-9].
Recently, studies have focused on understanding the properties of sclera biomechanics because the biomechanical properties of the sclera and lamina cribrosa determine the biomechanical changes of the optic papilla [1, 2], playing an important role in the process of RGC loss and optic nerve damage caused by increased in intraocular pressure (IOP) [3,4].
(22) No link has been specifically identified, but hypotheses exist that the higher CH measurement allows the lamina cribrosa to buffer the IOP rise, resulting in less damage to the nerves as they pass through the lamina; this can be pictured as the nerve tissue passes through the lamina cribrosa like electric cords passing through a hole in a wooden desk.
There will be no ophthalmoscopic changes in retro bulbar neuritis, unless the lesion is near to lamina cribrosa, so diagnosis is based on symptoms and investigations alone.
The slides of the PO section should contain the optic nerve head, lamina cribrosa, and postlaminar optic nerve in a single plane of section (Figure 3, c).
In glaucoma, acquired optic disc pits form due to localized depressions in the lamina cribrosa resulting from neuroretinal rim loss.
Further axonal collapse occurs because of native astroglial cells participation and resides in head of the optic nerve and lamina cribrosa. Hence axons suffer extensive damage and follow Wallerian degeneration with severe microfilament and microtubule breakdown as well as mitochondrial swelling [5].