he human axial skeleton consists of the head, vertebral column, sternum, and ribs. Chapter 5 focuses on the bony and soft tissue structures of the spine. Chapter 6 focuses on the thoracic rib cage and its function in ventilation. Chapter 7 completes the study of the axial skeleton by concentrating on the temporomandibular joints of the cranium. These chapters lay the foundation for understanding the structures and kinematics of the axial skeleton and how these structures provide proximal trunk stability necessary for upper and lower extremity function.