What bones are included in the axial skeleton?

The axial skeleton consists of the central core of the body, which includes the skull, vertebral column (vertebrae), ribs, and sternum. This portion of the skeleton primarily serves to protect the vital organs and support the body's structure.

The skull houses and protects the brain, while the vertebrae form the spine, supporting the body's posture and protecting the spinal cord. The ribs surround the thoracic cavity, providing protection for the heart and lungs, and the sternum acts as a central bone to which the ribs attach.

Other options describe elements of the appendicular skeleton, which includes bones of the limbs and girdles. For instance, the pelvis and the bones of the upper limbs (humerus, radius, and ulna) associated with the arms, as well as the scapula and bones related to the shoulder girdle, are all part of the appendicular skeleton and do not contribute to the axial skeleton. This distinction is essential for understanding the organization of the skeletal system.