The Skeletal System

Overview of the Skeletal System

The skeletal system is a complex framework composed of bones, cartilages, joints, and ligaments. It provides structural support, protection for internal organs, and facilitates movement through its interaction with the muscular system.

• Axial skeleton: Forms the central axis of the body and consists of 80 bones.

• Appendicular skeleton: Comprises the limbs and girdles, attaching the limbs to the axial skeleton.

Key functions: Support, protection, movement, mineral storage, blood cell formation (hematopoiesis), and energy storage.

Major Divisions of the Skeleton

• Axial skeleton: Includes the skull, vertebral column, and thoracic cage.

• Appendicular skeleton: Includes the pectoral girdle, pelvic girdle, and the bones of the upper and lower limbs.

The Human Skeleton

General Structure

The human skeleton is divided into two main parts: the axial skeleton and the appendicular skeleton. The axial skeleton forms the long axis of the body, while the appendicular skeleton consists of the limbs and girdles.

• Axial skeleton: 80 bones, including the skull, vertebral column, and thoracic cage.

• Appendicular skeleton: 126 bones, including the shoulder girdle, pelvic girdle, and limbs.

Example: The skull protects the brain, the vertebral column protects the spinal cord, and the thoracic cage protects the heart and lungs.

Importance of Skeletal Anatomy

Understanding the anatomy of the skeleton is crucial for anticipating clinical problems, such as pelvic dimensions that may affect labor and delivery. Knowledge of skeletal structure is also essential for careers in healthcare, sports medicine, and forensic science.

Learning Outcomes for Chapter 7A: The Skeleton

• Identify and describe the bones of the skull: Recognize the 8 cranial and 14 facial bones, and their important markings.

• Compare functions: Distinguish between the functions of the cranium (protection of the brain) and the facial skeleton (framework for the face, securing teeth, and providing passageways for air and food).

• Define boundaries: Understand the bony boundaries of the orbits, nasal cavity, and paranasal sinuses.

Additional info:

• The axial skeleton provides the main support for the body and protects the central nervous system and thoracic organs.

• The appendicular skeleton is essential for movement and manipulation of the environment.