The Skeletal System

Functions of the Skeletal System  Provides a framework for the muscles.  Supports and protects organs.  Storage centers.  Manufacture blood cells.

Structure of the Skeleton  Divided into two main parts:  1. Axial skeleton Skull, spine, ribs, and sternum. Skull, spine, ribs, and sternum. Protection. Protection.  Appendicular skeleton Shoulders, arms, hands, hips, legs, and feet. Shoulders, arms, hands, hips, legs, and feet. Movement. Movement.

Types of Bones  Strong long bones Arms and legs Arms and legs The shafts are called diaphyses The shafts are called diaphyses Ends are called epiphyses Ends are called epiphyses Form joints Form joints Produce red and white blood cells Produce red and white blood cells

 Short bones Wrists and ankles Wrists and ankles As broad as they are long As broad as they are long  Flat bones Ribs, skull, sternum Ribs, skull, sternum Protect Protect  Irregular bones vertebrae vertebrae

Cartilage  A strong, flexible connective tissue Line surfaces of joints Line surfaces of joints Cushion vertebrae Cushion vertebrae Support the nose and ears Support the nose and ears  Ossification: the process by which bone is formed, renewed, and repaired.

Joints  The point at which two bones meet. Fixed Fixed Small amount of movement Small amount of movement Mobile joints Mobile joints

 Ball-and-socket joint Allows the widest range of movement Allows the widest range of movement Shoulder and hip joints Shoulder and hip joints  Pivot joint Rotation Rotation First two vertebrae in the neck First two vertebrae in the neck  Ellipsoidal joint All ranges of motion except pivotal All ranges of motion except pivotal

 Hinge joint Fingers, toes, knees, elbows Fingers, toes, knees, elbows  Joints are lined with cartilage to reduce friction during movement.  Ligaments are tough bands of fibrous, slightly elastic tissue that bind bone to bone and prevent excessive movement.

 Tendons are fibrous cords that join muscle to bone or to other muscles.

Care of the Skeletal System  Nutrition Calcium Calcium Phosphorus Phosphorus  Exercise Weight Bearing Weight Bearing Increased Circulation Increased Circulation

Problems of the Skeletal System  Poor Nutrition  Infections  Sport and recreational mishaps  Accidents  Poor Posture

Fractures  Simple  Compound  Also classified according to the shape or pattern of the break:

 1. Hairline – incomplete, the two bones do not separate.  2. Transverse – completely across the bone  3. Comminuted – the bone shatters into more than two pieces

Osteoporosis  Bone density decreases and becomes brittle and easily fractured.  Menopause – lack of estrogen.  Prevent through diet and exercise.

Scoliosis  Lateral, side to side curvature of the spine.  Starts in childhood or adolescence and becomes more severe until the age where growth stops.  Screening programs.  Treatment: exercise, special brace, surgery.

Injuries to Joints  Dislocation: Where joint slides out of it’s normal position.  Torn cartilage: caused by a sharp blow or rotation of a joint.  Bunion: Painful swelling of the bursa in the first joint of the big two

 Bursitis: bursa in a joint becomes inflamed.  Arthritis: inflammation of a joint. Pain Pain Swelling Swelling Stiffness Stiffness Redness Redness  Osteoarthritis

Repetitive Motion Injury  Technology  Damage to tissues caused by prolonged, repeated movements.  Carpal tunnel syndrome.