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.

Structure

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 The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. ...

and presents at its apex a downward-directed process, the

spine of sphenoid bone The sphenoidal spine (Latin: "''spina angularis''") is a downwardly directed process at the apex of the great wings of the sphenoid bone that serves as the origin of the sphenomandibular ligament. Additional images File:Spine of sphenoid bone. ...

Cerebral surface

The superior or cerebral surface of each greater wing

ig. 1 IG, Ig, or ig may refer to: Companies * IG Farben, a former German industrial conglomerate * IG Group, a UK financial services company * IG Recordings, a record label formed by the Indigo Girls, an American folk/rock duo * Production I.G, a Japan ...

forms part of the middle cranial fossa; it is deeply concave, and presents depressions for the convolutions of the

temporal lobe The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in pro ...

of the brain. It has a number of foramina (holes) in it: * The foramen rotundum is a circular aperture at its anterior and medial part; it transmits the

maxillary nerve In neuroanatomy, the maxillary nerve (V) is one of the three branches or divisions of the trigeminal nerve, the fifth (CN V) cranial nerve. It comprises the principal functions of sensation from the maxilla, nasal cavity, sinuses, the palat ...

. * The foramen ovale is behind and lateral to this; it transmits the mandibular nerve, the accessory meningeal artery, and sometimes the

lesser petrosal nerve The lesser petrosal nerve (also known as the small superficial petrosal nerve) is the general visceral efferent (GVE) component of the glossopharyngeal nerve (CN IX), carrying parasympathetic preganglionic fibers from the tympanic plexus to the p ...

. * The

sphenoidal emissary foramen In the base of the skull, in the great wings of the sphenoid bone, medial to the foramen ovale, a small aperture, the sphenoidal emissary foramen, may occasionally be seen (it is often absent) opposite the root of the pterygoid process. When pr ...

is occasionally present; it is a small aperture medial to the foramen ovale, opposite the root of the pterygoid process; it opens below near the

scaphoid fossa In the pterygoid processes of the sphenoid, above the pterygoid fossa is a small, oval, shallow depression, the scaphoid fossa, which gives origin to the Tensor veli palatini The tensor veli palatini muscle (tensor palati or tensor muscle of the ...

, and transmits a small vein from the cavernous sinus. * The

foramen spinosum The foramen spinosum is a hole located in the greater wing of the sphenoid. It is located posterolateral to the foramen ovale and anterior to the sphenoidal spine. It allows the passage of the middle meningeal artery, middle meningeal vein and ...

, in the posterior angle near to and in front of the spine; it is a short canal that transmits the middle meningeal vessels and a recurrent branch from the mandibular nerve. * The

foramen petrosum The lesser petrosal nerve (also known as the small superficial petrosal nerve) is the general visceral efferent (GVE) component of the glossopharyngeal nerve (CN IX), carrying parasympathetic preganglionic fibers from the tympanic plexus to the p ...

, a small occasional opening, between the foramen spinosum and foramen ovale, for transmission of the

Lateral surface

The lateral surface

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is convex, and divided by a transverse ridge, the infratemporal crest, into two portions. * The superior temporal surface, convex from above downward, concave from before backward, forms a part of the

temporal fossa The temporal fossa is a fossa (shallow depression) on the side of the skull bounded by the temporal lines and terminating below the level of the zygomatic arch. Boundaries * Medial: frontal bone, parietal bone, temporal bone, and sphenoid bon ...

, and gives attachment to the

temporalis In anatomy, the temporalis muscle, also known as the temporal muscle, is one of the muscles of mastication (chewing). It is a broad, fan-shaped convergent muscle on each side of the head that fills the temporal fossa, superior to the zygomatic a ...

; * the inferior infratemporal surface, smaller in size and concave, enters into the formation of the infratemporal fossa, and, together with the infratemporal crest, serves as an attachment to the

lateral pterygoid muscle The lateral pterygoid muscle (or external pterygoid muscle) is a muscle of mastication. It has two heads. It lies superior to the medial pterygoid muscle. It is supplied by pterygoid branches of the maxillary artery, and the lateral pterygoid ne ...

. It is pierced by the foramen ovale and

, and at its posterior part is the

sphenoidal spine The sphenoidal spine (Latin: "''spina angularis''") is a downwardly directed process at the apex of the great wings of the sphenoid bone that serves as the origin of the sphenomandibular ligament. Additional images File:Spine of sphenoid bone ...

, which is frequently grooved on its medial surface for the

chorda tympani nerve The chorda tympani is a branch of the facial nerve that originates from the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. It joins the facial nerve (cranial nerve VII) inside the facia ...

. To the sphenoidal spine are attached the

sphenomandibular ligament The sphenomandibular ligament (internal lateral ligament) is one of the three ligaments of the temporomandibular joint. It is situated medially to - and generally separate from - the articular capsule of the joint. Superiorly, it is attached to the ...

and the

tensor veli palatini The tensor veli palatini muscle (tensor palati or tensor muscle of the velum palatinum) is a broad, thin, ribbon-like muscle in the head that tenses the soft palate. Structure The tensor veli palatini is found anterior-lateral to the levator ve ...

muscle. Medial to the anterior extremity of the infratemporal crest is a triangular process that serves to increase the attachment of the

; 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.

Orbital surface

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. * Its upper serrated edge articulates with the orbital plate of the

frontal bone The frontal bone is a bone in the human skull. The bone consists of two portions.'' Gray's Anatomy'' (1918) These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, pa ...

. * Its inferior rounded border forms the postero-lateral boundary of the

inferior orbital fissure The inferior orbital fissure is formed by the sphenoid bone and the maxilla. It is located posteriorly along the boundary of the floor and lateral wall of the orbit. It transmits a number of structures, including: * the zygomatic branch of the m ...

. * Its medial sharp margin forms the lower boundary of the superior orbital fissure and has projecting from about its center a little tubercle that gives attachment to the inferior head of the

lateral rectus Lateral is a geometric term of location which may refer to: Healthcare * Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral co ...

muscle; at the upper part of this margin is a notch for the transmission of a recurrent branch of the

lacrimal artery The lacrimal artery is an artery of the orbit. It is a branch of the ophthalmic artery. It accompanies the lacrimal nerve along the upper border of the lateral rectus muscle, travelling forward to reach the lacrimal gland. It supplies the lacri ...

. * Its lateral margin is serrated and articulates with the

zygomatic bone In the human skull, the zygomatic bone (from grc, ζῠγόν, zugón, yoke), also called cheekbone or malar bone, is a paired irregular bone which articulates with the maxilla, the temporal bone, the sphenoid bone and the frontal bone. It is s ...

. * Below the medial end of the superior orbital fissure is a grooved surface, which forms the posterior wall of the

pterygopalatine fossa In human anatomy, the pterygopalatine fossa (sphenopalatine fossa) is a fossa in the skull. A human skull contains two pterygopalatine fossae—one on the left side, and another on the right side. Each fossa is a cone-shaped paired depression deep ...

, and is pierced by the foramen rotundum.

Margin

Commencing from behind

that portion of the circumference of the great wing that extends from the body to the spine is irregular. * Its ''medial half'' forms the anterior boundary of the

foramen lacerum The foramen lacerum ( la, lacerated piercing) is a triangular hole in the base of skull. It is located between the sphenoid bone, the apex of the petrous part of the temporal bone, and the basilar part of the occipital bone. Structure The foram ...

, and presents the posterior aperture of the

pterygoid canal The pterygoid canal (also vidian canal) is a passage in the sphenoid bone of the skull leading from just anterior to the foramen lacerum in the middle cranial fossa to the pterygopalatine fossa. Structure The pterygoid canal runs through the me ...

for the passage of the corresponding nerve and artery. * Its ''lateral half'' articulates, by means of a synchondrosis, with the petrous portion of the temporal, and between the two bones on the under surface of the skull, is a furrow, the sulcus of the auditory tube, for the lodgement of the cartilaginous part of the

auditory tube Auditory means of or relating to the process of hearing: * Auditory system, the neurological structures and pathways of sound perception ** Auditory bulla, part of auditory system found in mammals other than primates ** Auditory nerve, also known ...

. In front of the spine the circumference presents a concave, serrated edge, bevelled at the expense of the inner table below, and of the outer table above, for articulation with the squamous part of the

. At the tip of the great wing is a triangular portion, bevelled at the expense of the internal surface, for articulation with the sphenoidal angle of the

parietal bone The parietal bones () are two bones in the skull which, when joined at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is nam ...

; this region is named the

pterion The pterion is the region where the frontal, parietal, temporal, and sphenoid bones join. It is located on the side of the skull, just behind the temple. Structure The pterion is located in the temporal fossa, approximately 2.6 cm beh ...

. Medial to this is a triangular, serrated surface, for articulation with the

; this surface is continuous medially with the sharp edge that forms the lower boundary of the superior orbital fissure, and laterally with the serrated margin for articulation with the

Development

The greater wing of the sphenoid bone starts as a separate bone, and is still separate at birth in humans.

Function

Clinical significance

It causes the superior lateral nasal occipital nerve to malfunction.

In other animals

In many mammals, e.g. the

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

, the greater wing of the sphenoid bone stays through life a separate bone called the alisphenoid.

Additional images

File:Orbital_bones.png, The seven bones that articulate to form the orbit. File:Gray187.png, Base of skull. Inferior surface. File:Gray189.png, Left infratemporal fossa. File:Gray190.png, The skull from the front. File:Gray310.png, Articulation of the mandible. Medial aspect. File:Gray889.png, Muscles of the right orbit. File:Slide24hhhh.JPG, Greater wing of sphenoid bone File:Slide8jjjj.JPG, Greater wing of sphenoid bone File:Slide1mmmm.JPG, Greater wing of sphenoid bone File:Slide7nnnn.JPG, Greater wing of sphenoid bone File:Slide3pppp.JPG, Greater wing of sphenoid bone

External links

* *

References

{{Authority control Bones of the head and neck