The sella, more formally known as the sella turcica (Latin for "Turkish saddle"), is a distinctive saddle-shaped depression located on the upper surface of the body of the sphenoid bone within the human skull. This crucial anatomical landmark serves as a protective enclosure for the pituitary gland.
The sella turcica is comprised of three main parts, which collectively form its characteristic "saddle" appearance:
- Tuberculum Sellae: This is the raised anterior (front) border of the sella turcica.
- Dorsum Sellae: Serving as the raised posterior (back) border, it forms the "back" of the saddle.
- Hypophyseal Fossa: Also known as the pituitary fossa, this is the central, low-lying depression within the sella turcica. It is precisely within this fossa that the vital pituitary gland resides.
Detailed Components of the Sella Turcica
Understanding each part individually highlights its specific role in containing and protecting the pituitary gland.
| Part of Sella Turcica | Description | Location |
|---|---|---|
| Tuberculum Sellae | A small, raised prominence forming the anterior boundary of the central depression. | Front of the sella turcica |
| Hypophyseal Fossa | The central, deepest part of the sella turcica, specifically designed to cradle the pituitary gland. | Center of the sella turcica |
| Dorsum Sellae | A prominent, quadrangular plate of bone that forms the posterior boundary of the central depression. | Back of the sella turcica, extending upwards |
Importance of the Sella Turcica
The sella turcica is more than just a bony depression; it is a vital protective enclosure for the pituitary gland, often referred to as the "master gland" due to its role in regulating numerous bodily functions. Its specific shape ensures the gland is well-cushioned and protected from external impacts, while its central location within the skull allows for optimal connectivity to the hypothalamus via the infundibulum.
Clinical Significance
The sella turcica is an area of significant clinical interest:
- Pituitary Tumors: Changes in the size or shape of the sella turcica, often detectable on imaging scans like MRI or CT, can indicate the presence of pituitary tumors (adenomas). These tumors can expand the hypophyseal fossa.
- Empty Sella Syndrome: This condition occurs when the sella turcica appears to be partially or completely filled with cerebrospinal fluid on imaging, compressing the pituitary gland and making the sella appear "empty."
- Surgical Landmark: It serves as a crucial anatomical landmark for neurosurgeons, particularly during transsphenoidal surgery, a common approach to access and remove pituitary gland tumors.
