Sella turcica

Bone: Sella turcica
Sphenoid bone. Upper surface. (There is no label for "Sella turcica", but "Tuberculum sellae" and "Fossa hypophyseos" are visible near center.)
Medial wall of left orbit. (Sella turcica labeled in upper right.)
Gray's	subject #35 147

The sella turcica (literally Turkish saddle) is a saddle-shaped depression in the sphenoid bone at the base of the human skull.

Anatomy

The seat of the saddle is known as the hypophyseal fossa, which holds the pituitary gland. The hypophyseal fossa is located in a depression in the body of the sphenoid bone. Located anteriorly to the hypophyseal fossa is the tuberculum sellae.

Completing the formation of the saddle posteriorly is the dorsum sellae which is continuous with the clivus, inferoposteriorly. The dorsum sellae is terminated laterally by the posterior clinoid processes.

Pathological Significance

Since the sella turcica forms a bony caudal border for the pituitary gland, a pituitary tumor can extend only 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.

See also

• Sphenoidal sinuses
• Empty sella syndrome

Additional images

Lateral wall of nasal cavity, showing ethmoid bone in position.

References

Marieb, Elaine Nicpon; (2004). Human Anatomy & Physiology / Elaine M. Marieb. 6th Edition. Pearson Education, Inc.. ISBN 0-8053-5462-X.  -- Page 209

External links

• Image at Indiana.edu
• Sella+turcica at eMedicine Dictionary

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