The middle clinoid process is a small, bilaterally paired elevation on either side of the

tuberculum sellae The tuberculum sellae (or the tubercle of the sella turcica) is a slight median elevation upon the superior aspect of the body of sphenoid bone (that forms the floor of the middle cranial fossa) at the anterior boundary of the sella turcica ( hypop ...

, at the anterior boundary of the

sella turcica The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalometric la ...

. A (larger)

anterior clinoid process The anterior clinoid process is a posterior projection of the sphenoid bone at the junction of the medial end of either lesser wing of sphenoid bone with the body of sphenoid bone. The bilateral processes flank the sella turcica anteriorly. The ...

is situated lateral to each middle clinoid process. The

diaphragma sellae The diaphragma sellae or sellar diaphragm is a small, circular sheet of dura mater forming an (incomplete) roof over the sella turcica and covering the pituitary gland lodged therein. The diaphragma sellae forms a central opening to accommodate the ...

(i.e. the dura forming the roof of the

cavernous sinus The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica. Structure The ...

) and the dura of the floor of the hypophyseal fossa (sella turcica) attach onto the middle clinoid processes. On each side of the body, the

internal carotid artery The internal carotid artery is an artery in the neck which supplies the anterior cerebral artery, anterior and middle cerebral artery, middle cerebral circulation. In human anatomy, the internal and external carotid artery, external carotid ari ...

passes between the anterior and middle clinoid processes.

Etymology

Clinoid likely comes from the

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

root ''klinein'' or the

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''clinare'', both meaning "sloped" as in "inclined."

References

Bones of the head and neck {{musculoskeletal-stub