Which of the following is NOT a component of the axial skeleton?

The humerus is not a component of the axial skeleton; instead, it is a long bone located in the upper limb, specifically the arm. The axial skeleton consists of the bones that form the central axis of the body, which includes the skull, vertebral column (spine), and thoracic cage (including the sternum and ribs). These structures provide support and protection for the brain, spinal cord, and organs in the thoracic cavity.

In contrast, the humerus connects the shoulder to the elbow and is part of the appendicular skeleton, which comprises the bones of the limbs and their attachments to the axial skeleton. Understanding this distinction is crucial when studying human anatomy, as it helps delineate between the central framework of the body and the limbs.