Anatomy Axial Skeleton

The axial skeleton consists of those bones that lie in the longitudinal axis of the body, running through its center of gravity

The bones of the axial skeleton include the bones of the skull, the hyoid, the ribs, sternum, and vertebrae

The appendicular skeleton contains the bones of the upper and lower extremities, including the pectoral (shoulder) girdle and pelvic girdle

The cranial bones are the: 1 frontal, 2 parietal, 2 temporal, 1occipital, 1 sphenoid, and 1 ethmoid.

The facial bones are the: 2 nasal, 2 maxillae, 2 zygomatics ( zygomas),1 mandible, 2 lacrimal, 2 palatine, 2 inferior nasal conchae, and 1 vomer.

A suture is an immovable fibrous joint in the skull where bone surfaces are closely united by connective tissue.

The coronal suture is located between the frontal bone and the 2 parietal bone

The sagittal suture is located between the 2 parietal bone

The lambdoidal sutures are found between the right and left parietal bones and the occipital bone

The squamosal sutures are located between the parietal bone and the temporal bone of each side

Wormian bones are small fragments of bones found in the sutures, particularly in the sagittal and lambdoidal sutures

Fontanels are membrane-filled spaces between the bones of the cranium seen at birth. These “soft spot” areas of dense fibrous connective tissue bridge the incompletely formed cranial bones. They close as the bones, and the brain, complete their develop-ment. Fontanels have two functions: (1) allow head to change shape while passing through the birth canal (2) allow for rapid growth of brain during the first two years.

The anterior (frontal) fontanel is found between the two parietal bones and the two segments of the frontal bone; closes between 18 - 24 months

The posterior (occipital) fontanel is found between the two parietal bones and the occiput; closes at 2 months.

The anterolateral (sphenoidal) fontanel is located at the junction of the frontal, parietal, temporal, and sphenoid bones; closes at 3 months