1. Human Systems:
Skeletal System

2. Skeletal system Bones and cartilage Alive and active
206 bones in humans
Support and protection
Helps maintaining homeostasis
Store minerals, make blood cells

3. Skeletal system Functions of bones
Protect organs (ribs protect heart and lungs)
Store minerals
Role in movement
Bone marrow (making blood cells)

4. Skeletal system

5. Bone structure
Bone is a living organ made up of different types of tissues
Connective tissue and minerals
Osteoblast cells – mineral deposition
Spongy bone – open spaces in bone
Compact bone – no visible open spaces
Bone marrow – two types
Red marrow – red and white blood cells synthesis
Yellow marrow – stores fats

6. Bone structure

7. Bone growth During development most bones are soft
Bone formation initiates as flexible tissue - cartilage
As development occurs cartilage is replaced by bone
During growth, bones also increase in size
During childhood, most bones still have growth plates of cartilage
These growth plates provide a place for bones to continue to grow

8. Joints A place where two or more bones meet is called a joint
Some joints, such as fixed joints, allow little or no movement
Many of the joints in the skull are fixed joints
Other joints, such as your shoulder, allow a lot of movement
Joints can be classified based on how the bones in a joint move
Gliding or sliding joints
Hinge joints
Ball and socket joints

9. Joints

10. Joints Joints are often placed under a great deal of stress
But they can withstand a lot of wear and tear because of their structure
Joints are held together by ligaments
Ligaments are strong elastic bands of connective tissue
They connect the bones in a joint
Also, cartilage covers the ends of many bones. Cartilage helps cushion the area in a joint where bones meet.

11. Injuries and diseases Fracture Dislocation of joint
Sprain – ligament stretched or torn
Osteoporosis
Bone density decreases
Bones become weak
Arthritis - joints may swell or stiffen
Gout – accumulation of uric acid
Nutrition and bone heath