Sphenoid sinus
Sinus sphenoidalis
RespiratoryOrgansHead
- What it is
- Paired, often unequal air spaces in the body of the sphenoid bone, directly below the pituitary gland and between the cavernous sinuses.
- Function
- Lightens the skull base; drains into the sphenoethmoidal recess above the superior turbinate.
- Size
- About 2 cm in each dimension (combined volume ~7 ml).
- Clinical note
- Surgeons reach pituitary tumours through the nose and this sinus (transsphenoidal surgery); the optic nerves and internal carotids bulge into its walls.