Extending lateralward from this on either side are two curved lines, one a little above the other. The squama, the expanded plate behind the foramen magnum, is situated above and behind the foramen magnum, is curved from above downward and from side to side. We use cookies to guarantee the best experience on our website. The internal surface of the squama of the occipital bone features: The internal occipital protuberance is a prominent midpoint of the cruciform eminence - a cross shaped bony prominence on the internal surface of the occipital bone. For questions regarding business inquiries. Osteology > The inferior nuchal line is a transverse ridge on the external surface of the occipital bone between the superior nuchal line and the foramen magnum. Superior to the groove for the transverse sinus is a depression that accommodates the occipital brain lobes ( cerebral fossa ) and the corresponding inferior depression houses the cerebellum ( cerebellar … The squamous part of occipital bone, is situated above and behind the foramen magnum, and is curved from above downward and from side to side. The basilar part of the occipital bone (also called the basioccipital) is the portion of the occipital bone extending anteriorly from the foramen magnum and joining with the body of the sphenoid bone. The upper two fossae are triangular and lodge the occipital lobes of the cerebrum; the lower two are quadrilateral and accommodate the hemispheres of the cerebellum. The external surface of the basioccipital features the pharyngeal tubercle. An approach for removal of brain, brain stem with spinal cord for autopsy and anatomical study Variant morphogenesis of squamous part of occipital bone in human skulls. The condylar canal is a bony passage located in the lateral part of the occipital bone posterior to the occipital condyle transmitting a vein from the sigmoid sinus. The superior nuchal line is a transverse ridge on the external surface of the occipital bone at the level of the external occipital protuberance. The semispinalis capitis muscle attaches between the inferior and the superior nuchal lines. Exceptions to this condition are, however, not infrequent: the left may be larger than the right or the two may be almost equal in size. The squamous part of occipital bone, is situated above and behind the foramen magnum, and is curved from above downward and from side to side. Occiput is a noun referring to the back of the head, it is not a synonym for the occipital bone. By disabling cookies, you may not view Vimeo videos. The internal surface of the lateral part of the occipital bone presents the groove for the sigmoid sinus. Human skull seen from below. ), This article incorporates text in the public domain from page 129 of the 20th edition of Gray's Anatomy (1918), https://en.wikipedia.org/w/index.php?title=Squamous_part_of_occipital_bone&oldid=948188623, Wikipedia articles incorporating text from the 20th edition of Gray's Anatomy (1918), Creative Commons Attribution-ShareAlike License, This page was last edited on 30 March 2020, at 16:56. The occipital bone is also known as "C0" because it joins the skull to the first cervical vertebra or C1, forming the atlanto-occipital joint. The website can not function properly without these cookies. It stays always separated from the foramen magnum by a bony border depending to the lateral parts. Occipital bone, inner surface. The squamous part is the largest area of this bone. By disabling these cookies, we will not be able to analyze site traffic or detect errors. These cookies guarantee the proper functioning of the site, in particular the connection to your account (IMAIOS session cookies), site security (Google Recaptcha cookies) and online payment (Stripe cookies). The basilar part of the occipital bone has an internal and an external surface.