Clivus (anatomy)

Clivus
Superior view of the clivus
Details
Identifiers
Latin	Clivus
TA	A02.1.00.051
FMA	54376
Anatomical terms of bone []

The clivus (Latin for "slope") is a part of the cranium at the skull base, a shallow depression behind the dorsum sellæ that slopes obliquely backward. It forms a gradual sloping process at the anterior most portion of the basilar occipital bone at its junction with the sphenoid bone. On axial planes, it sits just posterior to the sphenoid sinuses. Just lateral to the clivus bilaterally is the foramen lacerum (the internal carotid artery reaches the middle cranial fossa above the foramen lacerum), proximal to its anastomosis with the Circle of Willis. Posterior to the clivus is the basilar artery.

The pons sits on the clivus.

Clivus is also used as an abbreviated term for the clivus ocularis which is the sloping inner wall of the retina as it dips into the foveola in the macula of the eye. For this reason, and to disambiguate, the clivus is sometimes referred to as the Blumenbach clivus.

The abducens nerve (cranial nerve VI) tracks along the clivus during its course. Increased intracranial pressure can trap the nerve at this point and cause signs of palsy.

Clivus is also the site for chordoma (a rare malignant tumour.)

The clivus is an important landmark for checking for anatomical atlanto-occipital alignment; the clivus, when viewed on a lateral C-spine X-ray, forms a line which, if extended, is known as Wackenheim's clivus line. Wackenheim's clivus line should pass through the dens of the axis or be tangential to it.