The Skeleton-Skull

The Skeleton-

The skeleton is the bony framework of the body. It forms the cavities and fossae that protect some structures, forms the joints and gives attachment to muscles

The skeleton is described in two parts

 1.Axial

2.Appendicular

1.The axial skeleton consists of-

• Skull
• Vertebral column
• Sternum or breast bone
• Ribs.

 

2.The appendicular skeleton consists of-

• The bones of the upper limbs
• The two clavicles
• The two scapulae
• The bones of the lower limbs
• The two innominate bones of the pelvis.

1.Axial skeleton-

Skull

The skull is described in two parts, the cranium, which contains the brain, and the face. It consists of a number of bones which develop separately but fuse together as they mature. The only movable bone is the mandible or lower jaw.

 

Bone of Cranium-

The cranium consists of the following bones -

 

• Frontal bone (1)
• Parietal bones (2)
• Occipital bone (1)
• Temporal bones (2)
• Sphenoid bone (1)
• Ethmoid bone (1)

 

Bones of Face-

            Facial bones(14) consist of the following -

• Zygomatic bones (2)
• Maxillae (2)
• Nasal bones (2)
• Lacrimal bones (2)
• Vomer (1)
• Palatine bones (2)
• Inferior conchae (2)
• Mandible (1)

Function of the Skull-

• The cranium protects the delicate tissues of the brain.
• The bony eye sockets provide the eyes with some protection against injury and give attachment to the muscles which move the eyes.
• The temporal bone protects the delicate structures of the ear.
• Some bones of the face and the base of the skull give resonance to the voice because they have cavities called sinuses, containing air. The sinuses have tiny openings into the nasal cavity.
• The bones of the face form the walls of the posterior part of the nasal cavities. They keep the air passage open, facilitating breathing.
• The maxilla and the mandible provide alveolar ridges in which the teeth are embedded

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