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Body Of The Sphenoid Bone
The body of the sphenoid bone, more or less cubical in shape, is hollowed out in its interior to form two large cavities, the sphenoidal sinuses, which are separated from each other by a septum. Superior surface The superior surface of the body ig. 1presents in front a prominent spine, the ethmoidal spine, for articulation with the cribriform plate of the ethmoid bone; behind this is a smooth surface slightly raised in the middle line, and grooved on either side for the olfactory lobes of the brain. This surface is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the prechiasmatic groove, above and behind which lies the optic chiasma; the groove ends on either side in the optic foramen, which transmits the optic nerve and ophthalmic artery into the orbital cavity. Behind the chiasmatic groove is an elevation, the tuberculum sellae; and behind this is a deep depression, the saddle-shaped sella turcica (Turkish seat), the deepest pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphenoid Bone
The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended. Structure It is divided into the following parts: * 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 * two greater wings on the lateral side of the body and two lesser wings from the anterior side. * Pterygoid processes of the sphenoides, directed downwards from the junction of the body and the greater wings. Two sphenoidal conchae are situated at the anterior and inferior part of the body. Intrinsic ligaments of the sphenoid The more important of these are: * the pterygospinous, stretching between the spin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuberculum Sellae
The tuberculum sellae (or the tubercle of the sella turcica The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalometric ...) is a part of the sphenoid bone that is an elevation behind the chiasmatic groove. A variable slight to prominent median elevation forming the posterior boundary of the chiasmatic groove and the anterior boundary of the hypophysial fossa. Additional Images File:Slide1iiii.JPG, Tuberculum sellae References External links * Diagram at uni-mainz.de Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greater Wings Of The Sphenoid
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 and presents at its apex a downward-directed process, the spine of sphenoid bone. Cerebral surface The superior or cerebral surface of each greater wing ig. 1forms 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 foramen rotundum is a circular aperture at its anterior and medial part; it transmits the maxillary nerve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pons
The pons (from Latin , "bridge") is part of the brainstem that in humans and other bipeds lies inferior to the midbrain, superior to the medulla oblongata and anterior to the cerebellum. The pons is also called the pons Varolii ("bridge of Varolius"), after the Italian anatomist and surgeon Costanzo Varolio (1543–75). This region of the brainstem includes neural pathways and tracts that conduct signals from the brain down to the cerebellum and medulla, and tracts that carry the sensory signals up into the thalamus.Saladin Kenneth S.(2007) Anatomy & physiology the unity of form and function. Dubuque, IA: McGraw-Hill Structure The pons is in the brainstem situated between the midbrain and the medulla oblongata, and in front of the cerebellum. A separating groove between the pons and the medulla is the inferior pontine sulcus. The superior pontine sulcus separates the pons from the midbrain. The pons can be broadly divided into two parts: the basilar part of the pons ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occipital Bone
The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cerebrum. At the base of skull in the occipital bone, there is a large oval opening called the foramen magnum, which allows the passage of the spinal cord. Like the other cranial bones, it is classed as a flat bone. Due to its many attachments and features, the occipital bone is described in terms of separate parts. From its front to the back is the basilar part, also called the basioccipital, at the sides of the foramen magnum are the lateral parts, also called the exoccipitals, and the back is named as the squamous part. The basilar part is a thick, somewhat quadrilateral piece in front of the foramen magnum and directed towards the pharynx. The squamous part is the curved, expanded plate behind the foramen magnum and is the largest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clivus (anatomy)
The clivus (, Latin for "slope"), or Blumenbach clivus, is a bony part of the cranium at the base of the skull. It is a shallow depression behind the dorsum sellae of the sphenoid bone. It slopes gradually to the anterior part of the basilar occipital bone at its junction with the sphenoid bone. It extends to the foramen magnum. It is related to the pons and the abducens nerve (CN VI). Structure The clivus is a shallow depression behind the dorsum sellae of the sphenoid bone. It slopes gradually to the anterior part of the basilar occipital bone at its junction with the sphenoid bone. Synchondrosis of these two bones forms the clivus. The clivus extends inferiorly to the foramen magnum. On axial planes, it sits just posterior to the sphenoid sinuses. It is medial to the foramen lacerum (the internal carotid artery reaches the middle cranial fossa above the foramen lacerum), proximal to its anastomosis with the Circle of Willis. It is anterior to the basilar artery. On sagi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 foramen lacerum ( la, lacerated piercing) is a triangular hole in the base of skull. It is located between 3 bones: * the sphenoid bone, forming the anterior border. * the apex of petrous part of the temporal bone, forming the posterolateral border. * the basilar part of occipital bone, forming the posteromedial border. It is the junction point of 3 sutures of the skull: * the petroclival (petrooccipital) suture. * the sphenopetrosal suture. * the sphenooccipital suture. It is situated anteromedial to the carotid canal. Development The foramen lacerum fills with cartilage after birth. Function The foramen lacerum transmits many structures, including: * the artery of the pterygoid canal. * the recurrent artery of the foramen lacerum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. The lower seven cranial nerves and the major vessels to and from the brain traverse the temporal bone. Structure The temporal bone consists of four parts— the squamous, mastoid, petrous and tympanic parts. The squamous part is the largest and most superiorly positioned relative to the rest of the bone. The zygomatic process is a long, arched process projecting from the lower region of the squamous part and it articulates with the zygomatic bone. Posteroinferior to the squamous is the mastoid part. Fused with the squamous and mastoid parts and between the sphenoid and occipital bones lies the petrous part, which is shaped like a pyramid. The tympanic part is relatively small and lies inferior to the squamous part, anterior to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abducent Nerve
The abducens nerve or abducent nerve, also known as the sixth cranial nerve, cranial nerve VI, or simply CN VI, is a cranial nerve in humans and various other animals that controls the movement of the lateral rectus muscle, one of the extraocular muscles responsible for outward gaze. It is a somatic efferent nerve. Structure Nucleus The abducens nucleus is located in the pons, on the floor of the fourth ventricle, at the level of the facial colliculus. Axons from the facial nerve loop around the abducens nucleus, creating a slight bulge (the facial colliculus) that is visible on the dorsal surface of the floor of the fourth ventricle. The abducens nucleus is close to the midline, like the other motor nuclei that control eye movements (the oculomotor and trochlear nuclei). Motor axons leaving the abducens nucleus run ventrally and caudally through the pons. They pass lateral to the corticospinal tract (which runs longitudinally through the pons at this level) before e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tentorium Cerebelli
The cerebellar tentorium or tentorium cerebelli (Latin for "tent of the cerebellum") is an extension of the dura mater that separates the cerebellum from the inferior portion of the occipital lobes. Structure The cerebellar tentorium is an arched lamina, elevated in the middle, and inclining downward toward the circumference. It covers the top of the cerebellum, and supports the occipital lobes of the brain. Its anterior border is free and concave, and bounds a large oval opening, the tentorial incisure, through which pass the cerebral peduncles. It is attached, behind, by its convex border, to the transverse ridges upon the inner surface of the occipital bone, and there encloses the transverse sinuses; in front, to the superior angle of the petrous part of the temporal bone on either side, enclosing the superior petrosal sinuses. At the apex of the petrous part of the temporal bone the free and attached borders meet, and, crossing one another, are continued forward to be fix ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsum Sellae
The dorsum sellae is part of the sphenoid bone in the skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, t .... Together with the basilar part of the occipital bone it forms the clivus. In the sphenoid bone, the anterior boundary of the sella turcica is completed by two small eminences, one on either side, called the middle clinoid processes, while the posterior boundary is formed by a square-shaped plate of bone, the dorsum sellae, ending at its superior angles in two tubercles, the posterior clinoid processes, the size and form of which vary considerably in different individuals. Additional images File:Gray569.png, Tentorium cerebelli from above. File:Slide2iiii.JPG, Dorsum sellae References External links * * Bones of the head and neck {{musculoskeleta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Clinoid Process
The anterior boundary of the sella turcica is completed by two small eminences, one on either side, called the middle clinoid processes. It is found lateral to the sella turcica. Etymology Clinoid likely comes from the Greek root ''klinein'' or the Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ... ''clinare'', both meaning "sloped" as in "inclined." References Bones of the head and neck {{musculoskeletal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
