Chapter 14_Lesson 1 Skeletal System

Functions Provides a strong, stable, and mobile framework on which muscles can act Supports and protects internal organs Bones are storage centers for minerals such as calcium Manufacturing centers of the body’s blood cells Red bone marrow produces millions of red blood cells daily

Structure 1. Axial skeleton: 80 bones of the skull, spine, ribs, and sternum WHAT DO THESE PROTECT? 2. Appendicular skeleton: 126 bones of the shoulders, arms, hands, hips, legs, and feet

TYPES OF BONES Long Bones Short Bones Flat Bones Found in legs and arms Example: femur, humerus Short Bones Found in the wrists and ankles Broad/wide as they are long Flat Bones Examples: ribs and skull bones Thin, flat shape Serve to protect vital organs Irregular Bones Examples: vertebrea Have a shape that does not fit into any other category

Cartilage Cartilage is a strong, flexible connective tissue Line the surface of joints and enable them to move smoothly, cushion adjoining vertebrea, and support the nose and ears Babies skeleton is mostly cartilage As the body grows, most cartilage cells are replaced by bone cells and minerals through ossification

Joints The point at which 2 bones meet is called a joint Fixed joints (btw bones and skull) Small movement (vertebrea) Wide range (elbow, knee) IMAGINE YOUR LIFE WITHOUT JOINTS. WHAT ACTIVITIES WOULD YOU BE ABLE TO DO????

Types of Joints Ball-and-socket Example: shoulder and hip joints Allows the widest range of movement: Backward, forward, sideways, in a circle Pivot Example: first 2 vertebrea Allows rotation Ellipsoidal Example: joint in your wrist Allows all rotation except pivotal Hinge Examples: fingers, elbow and knee Allows bending and straightening

How are all of these connected???? The purpose is to reduce friction during movement Ligaments = bone to bone Tendons = muscle to bone; muscle to muscle

Caring for your skeletal system The body builds most of its bone mass in the teen years Nutrition – foods rich in calcium and phosphorus Strong bones and rigidity Exercise Activity, especially weight bearing activity, increases bone mass and circulation

Problems of the Skeletal System FRACTURES CLASSIFIED BY SHAPE/PATTERN OF BREAK Hairline – fracture is incomplete, the 2 parts of the bone do not separate Transverse - fracture is completely across the bone. Comminuted – bone shatters into more than 2 pieces

Joint Injuries DISLOCATION TORN CARTILAGE Bone slips away from its normal position at a joint Never attempt to replace a dislocated bone Physician should put bone back and immobilize the joint so the tissue can heal Serious joint injury. Can result from a sharp blow or severe twisting of joint

OSTEOPOROSIS SCOLIOSIS Bone density decreases, causing bone to become brittle and easily fractured As teens, you have opportunity to prevent osteoporosis by exercising and eating enough foods rich in calcium Lateral/side-to-side curvature of the spine

Inflammation of a joint Pain, swelling, and redness ARTHRITIS Inflammation of a joint Pain, swelling, and redness Wear and tear on the joint