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The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of the skull. It is composed of the
endocranium The endocranium in comparative anatomy is a part of the skull base in vertebrates and it represents the basal, inner part of the cranium. The term is also applied to the outer layer of the dura mater in human anatomy. Structure Structurally, th ...
and the lower parts of the calvaria.


Structure

Structures found at the base of the skull are for example:


Bones

There are five bones that make up the base of the skull: * Ethmoid bone * Sphenoid bone * Occipital bone *
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, part ...
*
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. T ...


Sinuses

* Occipital sinus * Superior sagittal sinus *
Superior petrosal sinus The superior petrosal sinus is one of the dural venous sinuses located beneath the brain. It receives blood from the cavernous sinus and passes backward and laterally to drain into the transverse sinus. The sinus receives superior petrosal veins, ...


Foramina of the skull This article lists foramina that occur in the human body. __TOC__ Skull The human skull has numerous openings (foramina), through which cranial nerves, arteries, veins, and other structures pass. These foramina vary in size and number, with ...

* Foramen cecum *
Optic foramen The ''optic foramen'' is the opening to the optic canal. The canal is located in the sphenoid bone; it is bounded medially by the body of the sphenoid and laterally by the lesser wing of the sphenoid. The superior surface of the sphenoid bone is b ...
*
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 fora ...
*
Foramen rotundum The foramen rotundum is a circular hole in the sphenoid bone of the skull. It connects the middle cranial fossa and the pterygopalatine fossa. It allows for the passage of the maxillary nerve (V2), a branch of the trigeminal nerve. Structure T ...
*
Foramen magnum The foramen magnum ( la, great hole) is a large, oval-shaped opening in the occipital bone of the skull. It is one of the several oval or circular openings (foramina) in the base of the skull. The spinal cord, an extension of the medulla oblonga ...
*
Foramen ovale There are multiple structures in the human body with the name foramen ovale (plural: ''foramina ovalia''; Latin for "oval hole"): * Foramen ovale (heart), in the fetal heart, a shunt from the right atrium to left atrium * Foramen ovale (skull), at ...
* Jugular foramen * Internal auditory meatus *
Mastoid foramen The mastoid foramen is a hole in the posterior border of the temporal bone. It transmits an emissary vein between the sigmoid sinus and the suboccipital venous plexus, and a small branch of the occipital artery, the posterior meningeal artery t ...
*
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 pres ...
*
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 ...


Sutures

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Frontoethmoidal suture The frontoethmoidal suture is the suture between the ethmoid bone and the frontal bone. It is located in the anterior cranial fossa The anterior cranial fossa is a depression in the floor of the cranial base which houses the projecting frontal ...
*
Sphenofrontal suture The sphenofrontal suture is the cranial suture between the sphenoid bone and 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 squamou ...
*
Sphenopetrosal suture The sphenopetrosal fissure (or sphenopetrosal suture) is the cranial suture between the sphenoid bone and the petrous portion of the temporal bone. It is in the middle cranial fossa The middle cranial fossa, deeper than the anterior cranial fos ...
*
Sphenoethmoidal suture The sphenoethmoidal suture is the cranial suture between the sphenoid bone and the ethmoid bone. It is located in the anterior cranial fossa The anterior cranial fossa is a depression in the floor of the cranial base which houses the projecting ...
*
Petrosquamous suture The petrosquamous suture is a cranial suture between the petrous portion and the squama of the temporal bone. It forms the Koerner's septum. The petrous portion forms the medial component of the osseous margin, while the squama forms the latera ...
*
Sphenosquamosal suture The sphenosquamosal suture is a cranial suture between the sphenoid bone and the squama 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 t ...


Other

* Sphenoidal lingula * Subarcuate fossa *
Dorsum sellae The dorsum sellae is part of the sphenoid bone in the skull. 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 o ...
*
Jugular process The jugular process is a quadrilateral or triangular bony plate projecting lateralward from the posterior half of the occipital condyle; it is a part of the lateral part of the occipital bone. The jugular process is excavated in front by the jugu ...
* Petro-occipital fissure *
Condylar canal The condylar canal (or condyloid canal) is a canal in the condyloid fossa of the lateral parts of occipital bone behind the occipital condyle. Resection of the rectus capitis posterior major and minor muscles reveals the bony recess leading to ...
*
Jugular tubercle The jugular tubercle is an oval eminence on the superior surface of the lateral parts of occipital bone. It overlies the hypoglossal canal and is sometimes crossed by an oblique groove for the glossopharyngeal, vagus, and accessory nerve The a ...
*
Tuberculum sellae The tuberculum sellae (or the tubercle of the sella turcica) is a part of the sphenoid bone that is an elevation behind the chiasmatic groove The superior surface of the body of the sphenoid bone is bounded behind by a ridge, which forms the ante ...
*
Carotid groove The carotid groove is an anatomical groove in the sphenoid bone located above the attachment of each great wing of the sphenoid bone. The groove is curved like the italic letter f, and lodges the internal carotid artery and the cavernous sinus Th ...
*
Fossa hypophyseos 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 cephalometr ...
*
Posterior clinoid processes In the sphenoid bone, the anterior boundary of the sella turcica is completed by two small eminences, one on either side, called the anterior clinoid processes, while the posterior boundary is formed by a square-shaped plate of bone, the dorsum s ...
*
Sigmoid sulcus Sigmoid means resembling the lower-case Greek letter sigma (uppercase Σ, lowercase σ, lowercase in word-final position ς) or the Latin letter S. Specific uses include: * Sigmoid function, a mathematical function * Sigmoid colon, part of the l ...
*
Internal occipital protuberance Along the internal surface of the occipital bone, at the point of intersection of the four divisions of the cruciform eminence, is the internal occipital protuberance. Running transversely on either side is a groove for the transverse sinus. Addit ...
*
Internal occipital crest In the occipital bone, the lower division of the cruciate eminence is prominent, and is named the internal occipital crest; it bifurcates near the foramen magnum and gives attachment to the falx cerebelli; in the attached margin of this falx is th ...
*
Ethmoidal spine The superior surface of the body of the sphenoid bone (Fig. 145) presents in front a prominent spine, the ethmoidal spine, for articulation with the cribriform plate of the ethmoid; behind this is a smooth surface slightly raised in the middle line ...
* Vestibular aqueduct *
Chiasmatic groove The superior surface of the body of the sphenoid bone is bounded behind by a ridge, which forms the anterior border of a narrow, transverse groove, the chiasmatic groove (optic groove, prechiasmatic sulcus), above and behind which lies the optic ...
* Middle clinoid process * Groove for sigmoid sinus *
Trigeminal ganglion A trigeminal ganglion (or Gasserian ganglion, or semilunar ganglion, or Gasser's ganglion) is the sensory ganglion at the base of each of the two trigeminal nerves (CN V), occupying a cavity ( Meckel's cave) in the dura mater, covering the tri ...
*
Middle cranial fossa The middle cranial fossa, deeper than the anterior cranial fossa, is narrow medially and widens laterally to the sides of the skull. It is separated from the posterior fossa by the clivus and the petrous crest. It is bounded in front by the po ...
*
Anterior cranial fossa The anterior cranial fossa is a depression in the floor of the cranial base which houses the projecting frontal lobes of the brain. It is formed by the orbital plates of the frontal, the cribriform plate of the ethmoid, and the small wings and fr ...
* Middle meningeal artery *
Cribriform plate In mammalian anatomy, the cribriform plate (Latin for lit. ''sieve-shaped''), horizontal lamina or lamina cribrosa is part of the ethmoid bone. It is received into the ethmoidal notch of the frontal bone and roofs in the nasal cavities. It sup ...
* Posterior cranial fossa *
Nasociliary nerve The nasociliary nerve is a branch of the ophthalmic nerve, itself a branch of the trigeminal nerve (CN V). It is intermediate in size between the other two branches of the ophthalmic nerve, the frontal nerve and lacrimal nerve. Structure The naso ...
*
Hypoglossal canal The hypoglossal canal is a foramen in the occipital bone of the skull. It is hidden medially and superiorly to each occipital condyle. It transmits the hypoglossal nerve. Structure The hypoglossal canal lies in the epiphyseal junction between ...


Additional images

File:Gray193.png , Base of the skull. Upper surface File:Schädelbasis1.jpg, Base of skull File:Base of skull 3.jpg, Base of skull - crista galli, cribriform plate and foramen cecum File:Base of skull 11.jpg, Base of skull - sella turcica File:Base of skull 24.jpg, The anterior, middle and posterior cranial fossa in different colors {{Authority control Skull