The sella turcica (

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power ...

for 'Turkish saddle') is a

saddle The saddle is a supportive structure for a rider of an animal, fastened to an animal's back by a girth. The most common type is equestrian. However, specialized saddles have been created for oxen, camels and other animals. It is not kno ...

-shaped depression in the body of the sphenoid bone of the

human skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

and of the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, t ...

s of other hominids including chimpanzees,

gorilla Gorillas are herbivorous, predominantly ground-dwelling great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four ...

s and

orangutan Orangutans are great apes native to the rainforests of Indonesia and Malaysia. They are now found only in parts of Borneo and Sumatra, but during the Pleistocene they ranged throughout Southeast Asia and South China. Classified in the gen ...

s. It serves as a cephalometric landmark. The

pituitary gland In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The hypop ...

or hypophysis is located within the most inferior aspect of the sella turcica, the hypophyseal

fossa Fossa may refer to: Animals * Fossa (animal), the common name of a carnivoran mammal of genus ''Cryptoprocta'' endemic to Madagascar * ''Fossa'', the Latin genus name of the Malagasy civet, a related but smaller mammal endemic to Madagascar Pla ...

Structure

The sella turcica is located in the sphenoid bone behind the chiasmatic groove and the tuberculum sellae. It belongs to the middle cranial fossa. The sella turcica's most inferior portion is known as the hypophyseal fossa (the "seat of the saddle"), and contains the

(hypophysis). In front of the hypophyseal fossa is the tuberculum sellae. Completing the formation of the saddle posteriorly is the

dorsum sellae The dorsum sellae is part of the sphenoid bone in the skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts a ...

, which is continuous with the clivus, inferoposteriorly. The dorsum sellae is terminated laterally by the posterior clinoid processes.

Development

It is widely believed that the development of the diaphragma sellae is a factor which determines the morphology of the sella turcica and its contents.

Function

The sella turcica forms a bony seat for the

Clinical significance

Empty sella syndrome is the condition of a shrunken or flattened pituitary gland. Since the sella turcica forms a bony

caudal Caudal may refer to: Anatomy * Caudal (anatomical term) (from Latin ''cauda''; tail), used to describe how close something is to the trailing end of an organism * Caudal artery, the portion of the dorsal aorta of a vertebrate that passes into the ...

border for the pituitary gland, a pituitary tumor usually extends upward in the rostral direction into the suprasellar region. 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 Pathognomonic (rare synonym ''pathognomic'') is a term, often used in medicine, that means "characteristic for a particular disease". A pathognomonic sign is a particular sign whose presence means that a particular disease is present beyond any dou ...

for a pituitary tumor. Some pituitary adenomas can extend inferiorly, growing downward and invading the sphenoid bone and cavernous sinus. Large adenomas can cause remodeling of the underlying sphenoid bone altering the shape of the sella turcica. Sella turcica is also usually used as a reference point with nasion to establish the base of the skull in cephalometric analysis. This is commonly done prior to orthodontic treatment. Proffit, William R. Contemporary Orthodontics, 4th Edition. C.V. Mosby, 122006. 6.5.2.1). vbk:978-0-323-04046-4#outline(6.5.2.1)

Etymology

''Sella turcica'' is from the

words ''sella'', meaning seat, and ''turcica'', meaning

Turkish Turkish may refer to: *a Turkic language spoken by the Turks * of or about Turkey ** Turkish language *** Turkish alphabet ** Turkish people, a Turkic ethnic group and nation *** Turkish citizen, a citizen of Turkey *** Turkish communities and mi ...

Additional images

File:Sella turcica - animation03.gif,

Human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

skull seen from side ( parietal bones and

temporal bone The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears ...

s have been removed). Sella turcica shown in red. File:Hypophysial fossa01.png, Hypophysial fossa shown in red. File:Sella turcica - animation02.gif, Sphenoid bone seen from above. Sella turcica shown in red. File:Base of skull 8.jpg, Base of skull - Sella turcica, tuberculum sellae and hypophyseal fossa

References

External links

Image at Indiana.edu
{{Authority control Bones of the head and neck