Sphenoid Bone
The Sphenoid Bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the temporal bone and the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended.The sphenoid bone is the only bone that connects to all the other bones of the cranium and its movement is responsible for "milking" the Pituitary Gland to secrete its hormones.
It is divided into the following parts:
- a median portion, known as the body of sphenoid bone, containing the sella turcica, which houses the Pituitary Gland as well as the paired paranasal sinuses, the sphenoidal sinuses
- two greater wings on the lateral side of the body and two lesser wings from the anterior side.
- Pterygoid processes of the sphenoides, directed downwards from the junction of the body and the greater wings.
- Two sphenoidal conchae are situated at the anterior and posterior part of the body.[1]
Importance of the Sphenoid
There are 22 bones that make up the skull, and the sphenoid is one of the 8 bones of the neurocranium. It is situated at the base of the skull, acting as the keystone. A keystone in architecture is the piece at the apex of an arch; it locks all the other pieces together and bears the weight. And just like a keystone holds everything together in an archway, so does the sphenoid in the skull.
The sphenoid articulates with 12 bones:
- frontal
- occipital
- parietals
- temporals
- zygomatics
- ethmoid
- vomer
- palatines
References