1. Skeletal System

2. The Skeletal System in Action !!

3. The number of bones Depends on your age Baby has about 275 bones
Adult has 206 bones
As a baby grows, some of the bones fuse together
Ex: Skull

4. 5 Functions of the Skeletal System
1. Movement: Skeletal system provides points of attachment for muscles. Your legs and arms move when the muscles pull on the bones.
2. Support: The backbone is the main support center for the upper body. It holds your head up and protects your spinal cord.
Muscle attached to bones!!

5. 5 Functions of the Skeletal System
3. Protection: The bones of your skull protect your brain. Your ribs protect your lungs and heart from injury.
4. Makes Blood: Red and white blood cells are formed by tissue called marrow, which is in the center of the bone.

6. 5 Functions of the Skeletal System
5. Storage: Bones store minerals, such as calcium and phosphorus, for use by the body

7. Two Major Skeletal System Parts
Axial Skeleton: The axial skeleton includes the skull, spine, ribs and sternum.
Appendicular Skeleton: The appendicular skeleton includes the appendages of the body, which are the shoulders, arms, hips, and legs.

8. Skeletal System Bones Four basic bone shapes
1. Long- arms, legs and fingers
2. Short- wrist and ankles
3. Flat- skull and sternum
4. Irregular- spine

9. Classification of Bones on the Basis of Shape
Figure 5.1
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

10. Bone Structure Typical Four Layers: Periosteum: Covers Bones
Compact Bone: Lies beneath the periosteum
Spongy Bone: Lies beneath the compact bone
Bone Marrow: Fills the gaps between the spongy bone

11. Periosteum
Dense, fibrous membrane covering bone; specialized connective tissue covering all bones of the body
Contains blood vessels
Essential for bone cell
survival and bone formation

12. Compact Bone Hard, strong layer directly underneath the periosteum
Gives bones strength
Framework of calcium and phosphate that makes the bone hard
Contains blood cells and blood vessels

13. Spongy Bone Located toward the ends of long bones
Has many small, open spaces that make bones lightweight

14. Bone marrow In the center of long bones
Some marrow is yellow and composed of fat cells
Red marrow produces red blood cells at a rate of 2-3 million cells per second

15. Bone Formation and Growth
Ossification - Process of converting other tissues to bone
Healthy bone tissue is always being formed & reformed
Osteoblasts – Bone forming cells that deposit the minerals calcium & phosphorus to make bone tissue hard
Osteoclasts – Break down bone tissue to release calcium and phosphorus in your blood to maintain healthy levels

16. Bone Formation
Childhood and adolescence: ossification exceeds bone loss
Early adulthood through middle age: ossification equals bone loss
After age 35: bone loss exceeds ossification

17. Joints of the Body
Ball and Socket Joint: Round end of bone fitting snuggly within another bone.
Ex. Shoulder and Hip

18. Joints of the Body
Hinge Joint: Movement at joint in one direction like a door.
Ex. Knee and Elbow

19. Joints of the Body
Pivot Joint: Bone resting atop another bone permitting free movement.
Ex. Neck, Wrist and Ankles

20. Joints of the Body Fixed Immovable: Joint does not move
Ex. Skull
Gliding Joint: Bones slipping over other bones with a free flowing movement.
Ex. Knuckles

21. The Connectors of the Body
Cartilage: It acts as a cushion between bones at a joint and protects the bones.

22. The Connectors of the Body
Ligaments: Connect bone to bone

23. The Connectors of the Body!!
Tendon: Attaches muscles to bones

24. Problems of Skeletal System
1. Fracture – any type of break in the bone
First slide copied from other PPT

25. 1a. Hairline Fracture – parts of the bone do not separate

26. 1b. Transverse Fracture – when the break is completely across the bone

27. 1c. Comminuted Fracture – bone shatters in more than 2 pieces

28. 1d. Compound Fracture – break in bone punctures the skin

29. Problems of the Skeletal System
Fracture: Break
Dislocation: Out of joint

30. Problems of the Skeletal System
Sprain: Swelling in the joint
Arthritis: Inflamed and stiff joints

31. Problems of the Skeletal System!!
Scoliosis: Curvature of the spine
Osteoporosis: Brittle bones

32. Problems of Skeletal System
Osteoporosis – condition in which there is a progressive loss of bone tissue
Bones weaken and become brittle
Caused by a lack of vitamin D and calcium
Milk and other dairy products are excellent sources.
Weight training and physical activity help increase bone mass

33. Problems of Skeletal System
Scoliosis
Lateral, side to side, curvature of the spine.
Depending on how serious, can be treated by light exercise, a special brace, or surgery.

34. Keeping Skeletal System Healthy
Consume Calcium and Vitamin D!
Found in dairy products such as milk and yogurt
Participate in regular physical activity
Light weight lifting can enhance bone mass.
Exercise promotes better blood circulation which helps to nourish bones

35. Keeping Skeletal System Healthy
Wear protective gear
Helmets, pads with contact sports, etc.
Keep teeth clean!!
Infections from cavities can potentially spread to jaw bone and other facial bones.