Chapter 22 The Human Body

Skeletal System Structure—Bones, cartilage, and connective tissue

Skeletal System Functions— 1. Gives support and shape 2. Protects internal organs 3. Forms blood cells 4. Stores calcium 5. Muscles attach to bone

Bone Structure Bone is a living tissue Osteoblasts: bone-producing cells

Types of Tissue Compact Bone: rigid and dense, with no open spaces Spongy Bone: many open spaces; provides strength and support

Marrow Red—produces both red and white blood cells Yellow—stores fat

Cartilage A tough connective tissue attached to surfaces of bones in areas near joints. Most of a baby’s skeleton is made of cartilage.

Joints A place where two or more bones meet

Types of Joints Fixed Ball and Socket Gliding Hinge Pivot

Fixed Joint Allows little or no movement Skull

Ball and Socket Joint Moves freely in all directions Shoulder, hip

Gliding Joint Bones glide over one another—allows for more flexibility Hand, wrist

Hinge Joint Allows your bones to flex and extend Knee, elbow

Pivot Rotating, side-to-side movement Vertebrae in the neck

Ligaments Strong, elastic bands of connective tissue Hold together joints

Injuries Fracture—broken bone Dislocated Joint—when 2 or more joints have been moved out of place Sprain—when a ligament has been stretched too far

Types of Fractures

Diseases Osteoporosis: causes bones to become less dense Arthritis: when joints swell and stiffen

Arthritis