Sphenoid bone anatomy. The Sphenoid Bone 2019-02-05

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Ethmoid Bone Anatomy

sphenoid bone anatomy

One makes its appearance in each wing between the foramen rotundum and foramen ovale about the eighth week. —Commencing from behind, that portion of the circumference of the great wing which extends from the body to the spine is irregular. The superior or temporal portion, convex from above downward, concave from before backward, forms a part of the temporal fossa, and gives attachment to the Temporalis; the inferior or infratemporal, smaller in size and concave, enters into the formation of the infratemporal fossa, and, together with the infratemporal crest, affords attachment to the Pterygoideus externus. The ophthalmic nerve is part of the. The anterior margin of the plate articulates with the posterior border of the vertical part of the palatine bone. Between the pre- and postsphenoid there are occasionally seen the remains of a canal, the canalis cranio-pharyngeus, through which, in early fetal life, the hypophyseal diverticulum of the buccal ectoderm is transmitted. The sphenoidal conchæ are each developed from a center which makes its appearance about the fifth month; at birth they consist of small triangular laminæ, 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, and between the ninth and twelfth years they unite with the sphenoid.

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Sphenoid Sinus Anatomy, Diagram & Location

sphenoid bone anatomy

Crammed between a group of bones in the frontal part of the cranium, it becomes one of the 8 bones that form the cranium. By the twenty-fifth year the sphenoid and occipital are completely fused. The butterfly shape looks very much like the body accompanied by the two wings which form the. They are attachment sites for the tentorium cerebelli dura mater , which separates the cerebellum from the inferior occipital lobes of the brain. The mucus secretions produced in the sinuses are continually being swept into the nose by the hair-like structures on the surface of the respiratory membrane lung lining tissues. 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 , and laterally with the serrated margin for articulation with the.

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II. Osteology. 5a. 5. The Sphenoid Bone. Gray, Henry. 1918. Anatomy of the Human Body.

sphenoid bone anatomy

The presphenoid is united to the postsphenoid about the eighth month, and at birth the bone is in three pieces Fig. It forms a passage for a branch of the called the mandibular nerve as well as the lesser petrosal nerve, emissary veins and the accessory meningeal artery. We use the information we collect through the use of cookies for our business purposes, including operation of the site, as well as to conduct research and product analyses to help us better develop and market our products. ¬óThe sphenoid articulates with twelve bones: four single, the vomer, ethmoid, frontal, and occipital; and four paired, the parietal, temporal, zygomatic, and palatine. Between the pre- and postsphenoid there are occasionally seen the remains of a canal, the canalis cranio-pharyngeus, through which, in early fetal life, the hypophyseal diverticulum of the buccal ectoderm is transmitted.

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II. Osteology. 5a. 5. The Sphenoid Bone. Gray, Henry. 1918. Anatomy of the Human Body.

sphenoid bone anatomy

The two plates diverge behind and enclose between them a V-shaped fossa, the pterygoid fossa, which contains the Pterygoideus internus and Tensor veli palatini. We subscribe to third-party societies services such as Google Analytics, Google+, Youtube, Vimeo, Facebook, Linkedin, Twitter and New Relic to further analyze the information collected with cookie technology and to help us improve the functioning of the site by monitoring traffic in popular areas and to modify the services and information we provide to meet customer demand. The Small Wings alæ parvæ. —The great wings, or ali-sphenoids, are two strong processes of bone, which arise from the sides of the body, and are curved upward, lateralward, and backward; the posterior part of each projects as a triangular process which fits into the angle between the squama and the petrous portion of the temporal and presents at its apex a downwardly directed process, the spina angularis sphenoidal spine. It is pierced by the and , and at its posterior part is the , which is frequently grooved on its medial surface for the. —Commencing from behind, that portion of the circumference of the great wing which extends from the body to the spine is irregular. You can refuse the setup of cookies by modifying the settings.

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Sphenoid bone

sphenoid bone anatomy

. The anterior surface of the pterygoid process is broad and triangular near its root, where it forms the posterior wall of the pterygopalatine fossa and presents the anterior orifice of the pterygoid canal. The superior pharyngeal constrictor muscle attaches to the inferior end of this plate. ¬óThe superior or cerebral surface of each great wing Fig. This is called the sella turcica. The arterial grooves are located on the inner surface of the skull produced by pressure from arteries, primarily the middle meningeal artery and its branches. This part shows articulation with the ethmoid bone in the anterior region, which lets the sinuses open into the nasal cavity.

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Greater wing of sphenoid bone

sphenoid bone anatomy

Intrinsic Ligaments of the Sphenoid. Its medial sharp margin forms the lower boundary of the superior orbital fissure and has projecting from about its center a little tubercle which gives attachment to the inferior head of the Rectus lateralis oculi; at the upper part of this margin is a notch for the transmission of a recurrent branch of the lacrimal artery. The most posterior farthest toward the back of the head of these is the sphenoid sinus. These cookies expires in just under a year. Each is irregular in form, and tapers to a point behind, being broader and thinner in front. Medial to the anterior extremity of the infratemporal crest is a triangular process which serves to increase the attachment of the Pterygoideus externus; extending downward and medialward from this process on to the front part of the lateral pterygoid plate is a ridge which forms the anterior limit of the infratemporal surface, and, in the articulated skull, the posterior boundary of the pterygomaxillary fissure. The medial plate of the pterygoid process is the medial division of the pterygoid process.

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The Sphenoid Bone

sphenoid bone anatomy

It is pierced by the foramen ovale and foramen spinosum, and at its posterior part is the spina angularis, which is frequently grooved on its medial surface for the chorda tympani nerve. ¬óAbout the ninth week of fetal life an ossific center appears for each of the small wings orbitosphenoids just lateral to the optic foramen; shortly afterward two nuclei appear in the presphenoid part of the body. The pterygoid canal transmits the greater and deep petrosal nerves from the middle cranial fossa to the pterygoid ganglion in the pterygopalatine fossa. Intrinsic Ligaments of the Sphenoid. ¬óAbout the ninth week of fetal life an ossific center appears for each of the small wings orbitosphenoids just lateral to the optic foramen; shortly afterward two nuclei appear in the presphenoid part of the body. There are fourteen centers in all, six for the presphenoid and eight for the postsphenoid. They begin to be developed before birth, and are of a considerable size by the age of six.

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Sphenoid bone

sphenoid bone anatomy

It consists of two sphenoidal air sinuses, separated with the help of a bony septum. The central part of the sphenoid includes the clinoid processes, and the pituitary fossa. Each bone articulates in front with the ethmoid, laterally with the palatine; its pointed posterior extremity is placed above the vomer, and is received between the root of the pterygoid process laterally and the rostrum of the sphenoid medially. They begin to be developed before birth, and are of a considerable size by the age of six. The greater wings curve upward, laterally, and backward to form a portion of the prominent middle cranial fossa. The anterior surface of the pterygoid process is broad and triangular near its root, where it forms the posterior wall of the pterygopalatine fossa and presents the anterior orifice of the pterygoid canal. The infratemporal crest is a bony ridge between the upper vertical temporal surface and the horizontally-oriented lower infratemporal surface of the greater wing of the sphenoid bone.

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