![]() One makes its appearance in each wing between the foramen rotundum and foramen ovale about the eighth week. The first ossific nuclei are those for the great wings ( alisphenoids). The sphenoidal conchae are each developed from a center that makes its appearance about the fifth month at birth they consist of small triangular laminae, and it is not until the third year that they become hollowed out and coneshaped about the fourth year they fuse with the labyrinths of the ethmoid bone, and between the ninth and twelfth years they unite with the sphenoid bone. There are fourteen centers in all, six for the presphenoid and eight for the postsphenoid.īy about the ninth week of fetal development an ossific center appears for each of the small wings (orbito-sphenoids) just lateral to the optic foramen this is followed by the appearance of two nuclei in the presphenoid part of the body. The greater part of the bone is ossified in cartilage. Until the seventh or eighth month of fetal development, the body of the sphenoid consists of two parts: one in front of the tuberculum sellæ, the presphenoid, with which the small wings are continuous the other, consisting of the sella turcica and dorsum sellae, the postsphenoid, with which are associated the great wings, and pterygoid processes. įigure 4 : Sphenoid bone at birth, posterior aspect. Medially, terminates in the anterior clinoid process.Posterior surface projects into the Sylvian point.Inferior surface forming upper boundary of superior orbital fissure.Superior surface forming floor of anterior cranial fossa.Tip forming the lateral end of the wing.These are two triangular wings projecting laterally from anterosuperior part of the body. This forms the posterior wall of the orbit Lesser wings This is divided into (by infratemporal crest): This forms the floor of the middle cranial fossa. ![]() Greater wings Superior or cerebral surface Sphenoidal sinuses are asymmetrical air sinuses in the body of the sphenoid, closed by sphenoidal conchae. Sphenoidal crest articulates with the perpendicular plate of ethmoid leading to formation of a part of the septum of nose.īasilar part of occipital bone Lateral surface Ĭarotid sulcus lodging cavernous sinus and internal carotid artery Sphenoidal sinuses Vaginal processes of medial pterygoid plate.Superior or cerebral surface Īrticulates with ethmoid bone anteriorly and basilar part of occipital bone posteriorly. The sphenoid articulates with the frontal, parietal, ethmoid, temporal, zygomatic, palatine, vomer, and occipital bones and helps to connect the neurocranium to the facial skeleton. and the caroticoclinoid, connecting the anterior to the middle clinoid process.the interclinoid, a fibrous process joining the anterior to the posterior clinoid process.the pterygospinous, stretching between the spina angularis and the lateral pterygoid plate (see cervical fascia).Two sphenoidal conchae are situated at the anterior and inferior part of the body. Pterygoid processes of the sphenoides, directed downwards from the junction of the body and the greater wings.two greater wings on the lateral side of the body and two lesser wings from the anterior side.a median portion, known as the body of sphenoid bone, containing the sella turcica, which houses the pituitary gland as well as the paired paranasal sinuses, the sphenoidal sinuses.Wedge-shaped sphenoid bone seen laterally
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