The base of skull, also known as the cranial base or the cranial floor, is the most inferior area of 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, th ...

. 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, ...

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 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 o ...

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 cer ...

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, ...

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. ...

Sinuses

* Occipital sinus * Superior sagittal sinus * Superior petrosal sinus

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 * Foramen lacerum * Foramen rotundum *

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 oblon ...

* Foramen ovale * Jugular foramen * Internal auditory meatus * Mastoid foramen * Sphenoidal emissary foramen * Foramen spinosum Endobasis - resistances beams

Sutures

* Frontoethmoidal suture * Sphenofrontal suture * Sphenopetrosal suture *

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 *

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 * Petro-occipital fissure * Condylar canal * Jugular tubercle *

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 *

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 * Sigmoid sulcus * Internal occipital protuberance *

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 * 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 * Anterior cranial fossa * Middle meningeal artery * Cribriform plate *

Posterior cranial fossa The posterior cranial fossa is part of the cranial cavity, located between the foramen magnum and tentorium cerebelli. It contains the brainstem and cerebellum. This is the most inferior of the fossae. It houses the cerebellum, medulla and pons. ...

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 na ...

* Hypoglossal canal

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