The prominent occipital bone characteristics or features include the external occipital protuberance and crest, occipital condyles, and the superior and inferior nuchal lines. Four nuchal lines are present on the external surface of the occipital bone. ➠ Extending laterally on either side from the middle of the medial nuchal line is the inferior nuchal line that almost runs parallel to superior nuchal line. Ano ang Imahinasyong guhit na naghahati sa daigdig sa magkaibang araw? What is the function of occipital condyle? The jugular process, which is a quadrilateral-shaped plate of bone, runs sideways from the posterior half of the condyle. These include: ➠ The highest nuchal line, which extends on either side from the external occipital protuberance to the mastoid process of the temporal bone, is the site of attachment for galea aponeurotica (muscle that covers the upper part of the cranium). The major features of this region include: Located on the midline of the external surface, the external occipital protuberance is a prominence that can be felt on touching. When we nod, we use the atlanto-occipital joint, which is the joint located between the atlas (vertebra C1) and the occipital bone. Sign up to receive the latest and greatest articles from our site automatically each week (give or take)...right to your inbox. These prominences are referred to as occipital condyles. Besides the medulla oblongata, meninges, subarachnoid space, the tonsils of the cerebellum, and other anatomical structures pass through the foramen. These include coronal suture (suture that joins the frontal bone to the two parietal bones on each side), lambdoid suture (suture that separates the occipital bone from the two parietal bones), sagittal suture (suture that extends from the lambdoid to the coronal suture between the parietal bones), and the squamous suture (suture that forms the boundary between the parietal and temporal bone on each side). Also, the paramastoid process that projects from the surface might articulate with the transverse process of the atlas. The internal surface of the squamous part is concave in shape. The angle of the union of the superior sagittal and transverse sinuses is called torcular herophili, and it appears as a depression on one or other side of the protuberance. The emissary veins (connecting veins in the head and the scalp that drain blood from the dural sinuses to veins outside the skull) pass through these canals from the transverse sinus. The cruciate eminence divides it into four fossae (concavity in a surface). You also have the option to opt-out of these cookies. The hypoglossal or twelfth cerebral nerve exits through the canal, and the meningeal branch of the ascending pharyngeal artery enters through it. It is only after the age of 25 years, that this plate ossifies, and the occipital and sphenoid bone become continuous. The longus capitis and rectus capitis anterior insert on either side of the middle line, whereas the anterior atlantooccipital membrane is attached right in front of the foramen magnum. Would you like to write for us? These bones perform the vital function of protecting the brain from damage in the event of trauma. The internal occipital protuberance lies at the point of intersection of the four divisions. The occipital bone is located at the lower section of the back of the skull. ➠ The superior nuchal line, which lies below the higher nuchal line, serves as a site of attachment for the trapezius, sternocleidomastoid, and splenius capitis muscles. It is continuous with the jugular notch. Results indicated that expression of sexual dimorphism in the occipital condylar region within the St. Bride's population is demonstrable but low. Condylar fossa lies behind each condyle, and the opening for the condylar canal lies at the bottom of the fossa. The function of the occipial condyle is to join the first These articulate with the atlanto-occipital joint (first cervical vertebra C1). The last section of the transverse sinus is accommodated by this groove. Forming the posterior surface of the skull, the occipital bone articulates with the two parietal bones, sphenoid bone, two temporal bones, and the atlas (first cervical vertebra). It is convex-shaped externally and concave-shaped internally. This human musculoskeletal system article is a stub. The jugular notch is located on the side of the condyle. Well, we're looking for good writers who want to spread the word. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. Smooth, rounded knobs on each side of the foramen magnum, where the skull articulates with the first vertebra. References. Characteristic of Vertebrates and Its Form. The upper two divisions accommodate the occipital lobes of the cerebrum, whereas the lower two divisions accommodate the cerebellar hemispheres (hemispheres of the cerebellum). These cookies do not store any personal information. But opting out of some of these cookies may have an effect on your browsing experience.
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