Alligator Basisphenoid

Description

The basisphenoid is an endochondral element and forms the rostroventral part of the braincase, thus the floor of rostral half of the encephalic cavity which houses the cerebrum, midbrain and pituitary gland, which fills the hypophyseal fossa. The internal carotid artery and abducens nerve both leave foramina in ventral to the dorsum sellae whereas numerous other cranial nerves associated with the eye (CN II, III, IV) pass through its bilaterally symmetrical rostral openings. The cultriform process, the rostral projection of the basisphenoid, extends into the interorbital septum. The element is sutured to the pterygoid, laterosphenoid, and basioccipital. The Vidian nerve, or the palatine ramus of the Facial nerve (CN VII) passes between the basisphenoid and pterygoid on its way to the suborbital region. Finally, the median pharyngeal tube passes through the ventral part of the basisphenoid to open into the basisphenoid recess, a midline pneumatic space.