Title 4. OSSEOUS SYSTEM.pdf ✅

PHARMD GURU Page 2 THE CRANIUM: It provides bony protection to the brain. It is described in two parts: base and vault. The base is a part on which the brain rests and the surrounding part is termed as the vault. The base is divided into the anterior, middle and posterior cranial fossae. The inner surfaces of all the cranial bones are supplied with blood vessels. The bones which form the cranium [Fig. 4.1 (a) and (b)] are: one frontal bone; two parietal bones; one occipital bone; one sphenoid bone; one ethmoid bone and two temporal bones.

PHARMD GURU Page 4 5. The Sphenoid Bone: The sphenoid bone is an irregular bone in the shape of a bat with its wings outstretched and lies in the centre of the base of the skull (Fig. 4.3). On the superior surface of the middle of the bone, there is a depression in which the pituitary gland rests. The wings are perforated by many openings for the passage of nerves and blood vessels.