In anatomy, the atlas (C1) is the most superior (first) cervical vertebra of the spine.
The occipital bone is a cranial dermal bone and the main bone of the occiput. 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.
The parietal bones are two bones in the skull which, when joined together at a fibrous joint, form the sides and roof of the cranium. In humans, each bone is roughly quadrilateral in form, and has two surfaces, four borders, and four angles. It is named from the Latin paries (-ietis), wall.
The posterior cranial fossa is part of the cranial cavity, located between the foramen magnum and tentorium cerebelli. It contains the brainstem and cerebellum.
The superior sagittal sinus, within the human head, is an unpaired area along the attached margin of the falx cerebri. It allows blood to drain from the lateral aspects of anterior cerebral hemispheres to the confluence of sinuses. Cerebrospinal fluid drains through arachnoid granulations into the superior sagittal sinus and is returned to venous circulation.
The falx cerebelli is a small sickle shaped fold of dura mater, projecting forwards into the posterior cerebellar notch as well as projecting into the vallecula of the cerebellum between the two cerebellar hemispheres. The name comes from two Latin words: falx, meaning "curved blade or scythe", and cerebellum, meaning "brain". Its base is attached, above, to the under and back part of the tentorium cerebelli; its posterior margin, to the lower division of the vertical crest on the inner surface of the occipital bone. The falx cerebelli generally lies somewhere between 2.8 and 4.5 cm in length and is approximately 1–2 mm thick.
The transverse sinuses, within the human head, are two areas beneath the brain which allow blood to drain from the back of the head. They run laterally in a groove along the interior surface of the occipital bone. They drain from the confluence of sinuses to the sigmoid sinuses, which ultimately connect to the internal jugular vein. See diagram : labeled under the brain as "SIN. TRANS.".
The mastoid part of the temporal bone is the back part of the temporal bone. Its rough surface gives attachment to various muscles and it has openings for the transmission of blood vessels. From its borders the mastoid part articulates with two other bones.
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.
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.
There are two surfaces of the squamous part of the frontal bone: the external surface, and the internal surface.
The internal surface of the squama frontalis of the frontal bone is concave and presents in the upper part of the middle line a vertical groove, the sagittal sulcus, the edges of which unite below to form a ridge, the frontal crest; the sulcus lodges the superior sagittal sinus, while its margins and the crest afford attachment to the falx cerebri.
The internal surface of the squamous part of the frontal bone is concave and presents in the upper part of the middle line a vertical groove, the sagittal sulcus, the edges of which unite below to form a ridge, the frontal crest; the sulcus lodges the superior sagittal sinus, while its margins and the crest afford attachment to the falx cerebri.
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 the occipital sinus, which is sometimes duplicated.
The superior pubic ramus is a part of the pubic bone which forms a portion of the obturator foramen. The obturator foramen, along with the ilium and other fused bones, forms part of either side of the pelvis.
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.
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 and the lower parts of the skull roof.
The following outline is provided as an overview of and topical guide to human anatomy:
The external occipital crest is part of the external surface of the squamous part of the occipital bone. It is a ridge along the midline, beginning at the external occipital protuberance and descending to the foramen magnum, that gives attachment to the nuchal ligament. It is also called the median nuchal line.
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Gray's Anatomy is an English language textbook of human anatomy originally written by Henry Gray and illustrated by Henry Vandyke Carter. Earlier editions were called Anatomy: Descriptive and Surgical, Anatomy of the Human Body and Gray's Anatomy: Descriptive and Applied, but the book's name is commonly shortened to, and later editions are titled, Gray's Anatomy. The book is widely regarded as an extremely influential work on the subject, and has continued to be revised and republished from its initial publication in 1858 to the present day. The latest edition of the book, the 41st, was published in September 2015.
