The skeleton serves three main functions: support, protection, and assisting in movement. It supports the body and provides attachment points for muscles. Bones protect internal organs like the brain, spinal cord, heart and lungs. When muscles contract, they cause bones to move. The skeleton also stores minerals, produces blood cells in bone marrow, and stores chemical energy. The skeleton is divided into the axial skeleton consisting of bones in the head, neck and trunk, and the appendicular skeleton consisting of the limbs and their attachments. Bone is a living connective tissue that can repair itself and has three layers: periosteum, compact bone and cancellous bone with marrow inside. Cartilage is also discussed along with joints and common skeletal disorders.

1. The Skeletal System Presented by Samantha Cook

3. Functions of the skeleton Support : the skeleton is the framework of the body, it supports the softer tissues and provides points of attachment for most skeletal muscles. Protection : the skeleton provides mechanical protection for many of the bodies internal organs, reducing risk of injury to them. For example, cranial bones protect the brain, vertebrae protect the spinal chord, and the ribcage protects the heart and lungs. Assisting in movement : skeletal muscles are attached to bones, therefore when the associated muscles contract they cause bones to move. Storage of minerals : bone tissues store several minerals, including calcium and phosphorus. When required bone releases minerals into the blood – facilitating the balance of minerals in the body. Production of blood cells : Bone marrow is a gelatinous material that produces white blood cells, red blood cells, or platelets. Storage of chemical energy : With increasing age some bone marrow changes from red bone marrow to yellow bone marrow which is and important chemical energy reserve.

4. Divisions of the skeleton The axial skeleton consists of bones that form the axis of the body and support and protect the organs of the head, neck, and trunk. The axial skeleton is made up of the skull, sternum, ribs, and vertebral column. The appendicular skeleton is composed of bones that anchor the appendages to the axial skeleton. The appendicular skeleton consists of the upper and lower extremities, and the shoulder and pelvic girdle.

6. Bone There are 206 bones in the human body that weigh approximately 20 pounds. The bones of the body allow us to stand and walk, and they protect internal organs. Bone is a living connective tissue that is capable of repairing itself when injured. The three layers of bone are periosteum , compact bone , and cancellous bone and marrow.

8. Cartilage Cartilage is strong but is more elastic than bone. It is found where bones join together and forms the nose and ears.

9. Joints Joints, or articulations, are the areas where two bones come together. The three basic types of joints are, fibrous joints , cartilaginous joints , and synovial joints .

12. Disorders of the Skeletal System Arthritis : inflammation of a joint. More than 100 forms are known, and all have different causes. Fracture : broken bones caused by stress on the bone. Fractures can occur in any bone in the body. Gout : inflammatory joint reaction caused by accumulation of uric acid crystals. The area that is usually affected is the big toe. Osteomyelitis : infection of the bone that is caused by bacteria, fungi, or contaminated foreign material such as an artificial joint. Sprain : injury to a joint. The joint is usually stretched beyond its normal range of movement.

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