The Skeletal System

1. The Skeletal System How the Skeletal System Works

2. The skeletal system consists of bones and connective tissue. • 206 bones • Bones of the skeleton range from the tiniest bone of the inner ear (about 0.25 cm long) to the longest bone of your thigh (femur) • Connective tissues cushion the bones, attach bone to bone, and attach bone to muscles

3. Your skeletal system has many functions, including:providing support for the bodyprotecting internal tissues and organs from damageacting as a framework for attached musclesallowing movement of limbs and igitsproducing new red and white blood cellsstoring fat and minerals, such as calcium and phosphorus

4. Bones • Living tissues formed into different layers • Outer layer is hard, densely packed, compact bone • Beneath spongy bone, less dense with a network of cavities filled with red bone marrow, where blood cells are produced • Some bones contain yellow bone marrow, type of connective tissue that stores fat

5. Bone Structure Humerus bone – Long bone

6. Wrist bone – short bone Rib bone – Flat bone

7. Connective Tissue • Three types of connective tissue: • Cartilage – strong, flexible act as a cushion between two bones to reduce friction, also act as a flexible structure for soft parts of the body (tip of the nose or outer ear) • All bones begin in the embryo as cartilage, early in development the cartilage hardens • Ossification process by which bone is formed, renewed, and repaired • Ligament is a band of fibrous, slightly elastic connective tissue that attaches one bone to another, attach to bones to create joints: attaches the two bones of the forearm to each other, forming the pivot joint • Tendon is fibrous cord that attaches muscle to the bone, muscles contract to move parts of the body.

8. ossification Cartilage surrounding the knee

9. ligament tendons

10. Joints – points at which bones meetsome joints do not move (bones of the skull); flexible joints include ball-and socket, hinge joints, pivot joints, and ellipsoidal joints. Ball and socket joint Hinge joint Pivot joint

11. Understanding Skeletal Problems Injuries and disorders harm the skeletal system • Poor nutrition, infections, sports injuries, and poor posture, degenerative disorders can also be problems • Compound fractures – broken end of the bone breaks through the skin • Simple fracture broken bones doen not break through the skin • Hairline fracture – parts of the bone do not separate • Transverse fractures when the fracture is completely across the bone • Comminuted fracture when the bone shatters inot more than two pieces

12. hairline compound

13. Comminuted fracture Transverse fracture

14. Injuries to joints can occur from overuse strain or disease • Dislocation – bone slips out of place, tearing the ligaments that attach the bone at the joint (reset joint and immobilize until healed) • Torn cartilage – sharp blow to a joint or a severe twisting of a joint, (surgery removes pieces of the damaged cartilage) • Bursitis – painful inflammation of bursa (fluid-filled sac) that helps reduce friction in the joints • Bunions – painful swellings of the bursae in the first joints of big toes ( wearing ill-fitting shoes make bunions worse, larger ones require surgery) • Arthritis - inflammation of a joint, from injury, natural wear and tear or autoimmune disease ( immune system mistakenly attacks itself, targeting the cells, tissue and organs of own body)

15. Torn cartilage Dislocation knee cap

16. Bursitis Bunions Arthritis

17. Repetitive Motion Injury • Prolonged, repeated movements (sewing or computer work) • Carpal tunnel syndrome – ligaments and tendons in the wrist swell (numbness, a tingling sensation in thumb and forefinger, pain and weakness in hand • Osteoporosis – progressive loss of bone tissue