Search results
Results From The WOW.Com Content Network
The occipital bone overlies the occipital lobes of the cerebrum. At the base of the skull in the occipital bone, there is a large oval opening called the foramen magnum, which allows the passage of the spinal cord. Like the other cranial bones, it is classed as a flat bone. Due to its many attachments and features, the occipital bone is ...
This begins on the cranial surface of the bone immediately above the foramen magnum, and is directed lateralward and forward above the condyle. It may be partially or completely divided into two by a spicule of bone; it gives exit to the hypoglossal or twelfth cerebral nerve, and entrance to a meningeal branch of the ascending pharyngeal artery.
Near the middle of the squamous part of occipital bone is the external occipital protuberance, the highest point of which is referred to as the inion. The inion is the most prominent projection of the protuberance which is located at the posterioinferior (rear lower) part of the human skull. The nuchal ligament and trapezius muscle attach to it.
The clivus (/ ˈ k l aɪ v ə s /, [1] Latin for "slope") or Blumenbach clivus is a part of the occipital bone at the base of the skull. [2] It is a shallow depression behind the dorsum sellae of the sphenoid bone. It slopes gradually to the anterior part of the basilar occipital bone at its junction with the sphenoid bone. It extends to the ...
2 Additional images. Toggle the table of contents. Base of skull. 13 languages. ... Ethmoid bone; Sphenoid bone; Occipital bone; Frontal bone; Temporal bone; Exobasis ...
From the external occipital protuberance, an often faintly marked ridge or crest, the median nuchal line, descends to the foramen magnum and affords attachment to the nuchal ligament. Running from the middle of this line across either half of the nuchal plane is the inferior nuchal line .
The nuchal lines are four curved lines on the external surface of the occipital bone: The upper, often faintly marked, is named the highest nuchal line, but is sometimes referred to as the Mempin line or linea suprema, and it attaches to the epicranial aponeurosis. Below the highest nuchal line is the superior nuchal line.
It is homologous to the basilar part of the occipital bone. In the ancestral tetrapod, the basioccipital makes up most of a large central knob-like surface, the occipital condyle, which articulates with the vertebrae as a ball-and-socket joint. This plesiomorphic ("primitive") state is retained by modern reptiles and birds.