1. Chapter 14_Lesson 1
Skeletal System

2. 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

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

4. 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

5. 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

6. 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????

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

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