The Sella turcica
(literally Turkish saddle
) is a saddle-shaped depression in the sphenoid bone
at the base of the human skull
The seat of the saddle is known as the hypophyseal fossa which holds the pituitary gland. Located anteriorly to the hypophyseal fossa is the tuberculum sellae.
Completing the formation of the saddle posteriorly is the dorsum sellae. The dorsum sellae is terminated laterally by the posterior clinoid processes.
Since the sella turcica forms a bony caudal border for the pituitary gland, a pituitary tumor can only extend upward in the rostral direction. This can result in compression of the optic chiasm which lies on top of the pituitary, enveloping the pituitary stalk. Compression of the optic chiasm can lead to bitemporal hemianopsia, and when there is no relevant trauma, this clinical finding is pathognomonic for a pituitary tumor.
ReferencesMarieb, Elaine Nicpon;
(2004). Human Anatomy & Physiology / Elaine M. Marieb. 6th Edition
. Pearson Education, Inc.. ISBN 0-8053-5462-X. -- Page 209