Bone: Occipital bone
Sagittal section of skull. (Occipital bone is at right, in blue. )
Base of the skull. Upper surface. (Occipital bone is at bottom, in blue. )
Gray's	subject #31 129
Articulations	the two parietals, the two temporals, the sphenoid, and the atlas

The occipital bone, a saucer-shaped membrane bone situated at the back and lower part of the cranium, is trapezoid in shape and curved on itself. Introduction ( classes Long bones body or Diaphysis Medullary canal The parietal bones are bones in the Human Skull and form by their union the sides and roof of the Cranium. The temporal bones are situated at the sides and base of the Skull. The sphenoid bone (from Greek sphenoeides, "wedgelike" is a Bone situated at the base of the Skull in front of the Temporals and basilar In Anatomy, the atlas (C1 is the topmost (first Cervical vertebra of the spine. It is pierced by a large oval aperture, the foramen magnum, through which the cranial cavity communicates with the vertebral canal. In Anatomy, in the Occipital bone, the foramen magnum (Latin 'great hole' is one of the several oval or circular apertures in the base of the Skull (the The cranial cavity, or intracranial space, is the space formed inside the Skull. The spinal canal (or vertebral canal or spinal cavity) is the space in Vertebrae through which the Spinal cord passes

• The curved, expanded plate behind the foramen magnum is named the squama occipitalis. The squama of the Occipital bone, situated above and behind the Foramen magnum, is curved from above downward and from side to side
• The thick, somewhat quadrilateral piece in front of the foramen is called the basilar part of occipital bone. The basilar part of the Occipital bone extends forward and upward from the Foramen magnum, and presents in front an area more or less quadrilateral in outline
• On either side of the foramen are the lateral parts of occipital bone. The lateral parts of the Occipital bone are situated at the sides of the foramen magnum on their under surfaces are the condyles for articulation with the superior facets of the atlas

Contents 1 Foramen magnum 2 Angles 3 Borders 4 Structure 5 Additional images 6 See also

Foramen magnum

See also Foramen magnum

The foramen magnum is a large oval aperture with its long diameter antero-posterior; it is wider behind than in front where it is encroached upon by the condyles. In Anatomy, in the Occipital bone, the foramen magnum (Latin 'great hole' is one of the several oval or circular apertures in the base of the Skull (the

It transmits the medulla oblongata and its membranes, the accessory nerves, the vertebral arteries, the anterior and posterior spinal arteries, and the membrana tectoria and alar ligaments. The medulla oblongata is the lower portion of the Brainstem. It deals with autonomic functions such as breathing and blood pressure In Anatomy, the accessory nerve is a Nerve that controls specific Muscles of the neck The vertebral arteries are branches of the subclavian arteries. The posterior spinal artery ( dorsal spinal artery) arises from the Vertebral artery, adjacent to the Medulla oblongata. The alar ligaments connect the sides of the Dens (on the axis or the second Cervical Vertebra) to tubercles on the Medial side of

Angles

The superior angle of the occipital bone articulates with the occipital angles of the parietal bones and, in the fetal skull, corresponds in position with the posterior fontanelle. The parietal bones are bones in the Human Skull and form by their union the sides and roof of the Cranium. The posterior fontanelle (or occipital fontanelle) is triangular in form and is situated at the junction of the Sagittal suture and Lambdoidal suture.

The inferior angle is fused with the body of the sphenoid. The lateral angles are situated at the extremities of the grooves for the transverse sinuses: each is received into the interval between the mastoid angle of the parietal and the mastoid part of the temporal. For the transverse pericardial sinus see Pericardial sinus. The transverse sinuses (left and right lateral sinuses within a human head

Borders

The superior borders extend from the superior to the lateral angles: they are deeply serrated for articulation with the occipital borders of the parietals, and form by this union the lambdoidal suture. The lambdoid suture (or lambdoidal suture) is a dense fibrous Connective tissue Joint on the posterior aspect of the Skull that

The inferior borders extend from the lateral angles to the inferior angle; the upper half of each articulates with the mastoid portion of the corresponding temporal, the lower half with the petrous part of the same bone.

These two portions of the inferior border are separated from one another by the jugular process, the notch on the anterior surface of which forms the posterior part of the jugular foramen. The jugular Foramen, a large Aperture in the Base of the skull.

Structure

The occipital, like the other cranial the outer and inner tables, between which is the cancellous tissue or diploë; the bone is especially thick at the ridges, protuberances, condyles, and anterior part of the basilar part; in the inferior fossæ it is thin, semitransparent, and destitute of diploë. Cancellous Bone is a type of Osseous tissue with a low density and strength but very high Surface area, that fills the inner cavity of long bones In the cranial bones the layers of compact tissue are familiarly known as the tables of the skull; the outer one is thick and tough the inner is thin dense and brittle and hence is In Human anatomy, the basilar artery is one of the arteries that supplies the Brain with oxygen-rich blood

Additional images

Cranial bones	Base of skull. Inferior surface.	Membrana tectoria, transverse, and alar ligaments.	Median sagittal section through the occipital bone and first three cervical vertebræ.
Muscles connecting the upper extremity to the vertebral column.	Upper part of medulla spinalis and hind- and mid-brains; posterior aspect, exposed in situ.	Muscles of the pharynx, viewed from behind, together with the associated vessels and nerves.

This article was originally based on an entry from a public domain edition of Gray's Anatomy. The public domain is a range of abstract materials &ndash commonly referred to as Intellectual property &ndash which are not owned or controlled by anyone Henry Gray's Anatomy of the Human Body (or Gray's Anatomy as it has commonly been shortened is an English-language Human anatomy Textbook As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.

See also

• Bone terminology
• Comparative anatomy
• Neanderthal
• Occipital bun
• Terms for anatomical location
• Ossification of occipital bone

Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce Comparative anatomy is the study of similarities and differences in the Anatomy of Organisms It is closely related to Evolutionary biology and Phylogeny The Neanderthal (neɪˈændərtɑːl also with /niː-/ and /-θɔːl/ or Neandertal, is an extinct member of the Homo genus that is known from Occipital bun is a morphological term used to describe a prominent bulge or projection of the Occipital bone at the back of the Skull. In fields of Anatomy, anatomical terms of location are descriptive terms to help identify relative positions or directions within a species The Planum occipitale 3 of the squama of the Occipital bone is developed in membrane, and may remain separate throughout life when it constitutes the interparietal

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