Greater wing of sphenoid bone

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The greater wing of the sphenoid bone, or alisphenoid, is a bony process of the sphenoid bone; there is one on each side, extending from the side of the body of the sphenoid and curving upward, laterally, and backward.

The greater wings of the sphenoid are two strong processes of bone, which arise from the sides of the body, and are curved upward, laterally, and backward; the posterior part of each projects as a triangular process that fits into the angle between the squamous and the petrous part of the temporal bone and presents at its apex a downward-directed process, the spine of sphenoid bone.

The superior or cerebral surface of each greater wing forms part of the middle cranial fossa; it is deeply concave, and presents depressions for the convolutions of the temporal lobe of the brain. It has a number of foramina (holes) in it:

The lateral surface is convex, and divided by a transverse ridge, the infratemporal crest, into two portions.

It is pierced by the foramen ovale and foramen spinosum, and at its posterior part is the sphenoidal spine, which is frequently grooved on its medial surface for the chorda tympani nerve.

To the sphenoidal spine are attached the sphenomandibular ligament and the tensor veli palatini muscle.

Medial to the anterior extremity of the infratemporal crest is a triangular process that serves to increase the attachment of the lateral pterygoid muscle; extending downward and medialward from this process on to the front part of the lateral pterygoid plate is a ridge that forms the anterior limit of the infratemporal surface, and, in the articulated skull, the posterior boundary of the pterygomaxillary fissure.

The orbital surface of the great wing , smooth, and quadrilateral in shape, is directed forward and medially and forms the posterior part of the lateral wall of the orbit.

This page was last edited on 11 February 2018, at 22:57 (UTC).
Reference: https://en.wikipedia.org/wiki/Great_wings_of_the_sphenoid under CC BY-SA license.

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