Anatomy & Physiology I and II

Anatomy & Physiology Study Guide

Chapter 8: The Skeletal System The entire human skeleton can be divided into two distinct categories: the axial skeleton and the appendicular skeleton. 8.1 Axial Skeleton The bones of the axial skeleton include the skull and associated bones, the thoracic cage, and the vertebral column. The axial skeleton forms the longitudinal axis of the body. The axial skeleton has 80 bones, which is roughly 40 percent of the bones in the human body. The axial components are: • The skull (8 cranial bones and 14 facial bones) • Bones associated with the skull (6 auditory ossicles and the hyoid bone) • The vertebral column (24 vertebrae with the sacrum and the coccyx) • The thoracic cage (the sternum and 24 ribs) The axial skeleton protects and supports the central nervous system (the brain and the spinal cord) and the organs in the ventral body cavities. The muscles of the head, neck, and trunk attach to the framework of the axial skeleton. The framework also stabilizes and supports the limbs of the appendicular skeleton.

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