The lamina cribrosa forms the bottom of the optic cup on the inner surface of the optic nerve head. On the outer surface of the optic nerve head, the posterior part of the lamina cribrosa faces the anterior region of the optic nerve.
Is lamina a Cribrosa?
The lamina cribrosa (LC) is a reticulated, sieve-like structure that fills the posterior scleral foramen, which unmyelinated retinal ganglion cell (RGC) axons pass through before converging as the optic nerve (ON).
What is the fundus of the internal auditory canal?
The fundus separates the internal auditory canal from the cochlea and vestibule which are located in close proximity. [2] It is divided into superior and inferior segments by the transverse crest (also called the falciform crest).
What is the pathway of the optic nerve?
The optic nerve directs the afferent limb of the reflex pathway. Light stimulates the retinal ganglionic cells. The impulses travel through the optic nerve (CN II), which projects bilaterally to the pretectal nucleus in the midbrain, and then projects to the Edinger-Westphal nucleus.
What is the area Cribrosa?
The base and sides are surrounded by cortical tissue, and the apex protrudes into the renal calyces. These protrusions are called renal papillae, whose surface is perforated by openings of numerous papillary ducts (of Bellini) and is thus called the area cribrosa.
What passes through the lamina cribrosa?
Lamina cribrosa may refer to: Lamina cribrosa sclerae, a mesh-like structures which allows nerve fibres of the optic nerve to pass through the sclera.
Is lamina cribrosa part of sclera?
The nerve fibers forming the optic nerve exit the eye posteriorly through a hole in the sclera that is occupied by a mesh-like structure called the lamina cribrosa. It is formed by a multilayered network of collagen fibers that insert into the scleral canal wall.
What is Vestibulocochlear?
The vestibulocochlear nerve (auditory vestibular nerve), known as the eighth cranial nerve, transmits sound and equilibrium (balance) information from the inner ear to the brain.
What is fundus of internal acoustic meatus?
Internal acoustic meatus (IAM) is a canal which is terminated with a fundus located inside the pyramid of the temporal bone. This plate separates the cochlea and vestibule from the IAM, and is defined as a fundus of the internal acoustic meatus (FIAM). The FIAM constitutes also the medial wall of the labyrinth.
What are the 3 visual pathways?
Visual pathway
- The retina.
- The optic nerve (CN II)
- The optic chiasm and tract (reticulogeniculate tract)
- The pretectal connections of the visual pathway.
- The lateral geniculate body.
- Optic radiation and visual cortex.
What is the correct pathway of vision?
The visual pathway consists of the retina, optic nerves, optic chiasm, optic tracts, lateral geniculate bodies, optic radiations, and visual cortex. The pathway is, effectively, part of the central nervous system because the retinae have their embryological origins in extensions of the diencephalon.
Where are medullary rays found?
The medullary rays are well-defined anatomic structures consisting of bundles of renal tubules which form in the renal cortex and continue through the renal medulla as the medullary striations.
What is the function of the lamina cribrosa?
The lamina cribrosa of the optic nerve head serves two contrasting roles; it must be porous to allow retinal ganglion cell axons to pass through, and yet at the same time, it must also provide adequate structural support to withstand the stresses and strains across it.
Where is the cribriform plate located?
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.
Can EDI SD-OCT be used to assess lamina cribrosa in glaucoma?
Using EDI SD-OCT, the full-thickness lamina cribrosa was clearly visualized in all eyes examined. This technique should facilitate the investigation on the lamina cribrosa in glaucoma, and may provide additional insight into the pathogenesis of glaucomatous optic neuropathy.
