1. EFFECT OF FITNESS ON BONE
When bones are subjected to regular physical activity and habitual loads, they tend to become denser and more mineralized
E.g. Right forearm of the right-handed tennis players is more dense than her left one from using it more frequently
Inactivity works in the opposite direction, leading to a decrease in weight and strength
E.g. loss of bone mass has been noted in bed-ridden patients, inactive senior citizens and astronauts

2. THE HUMAN SKELETON

3. FUNCTION OF THE SKELETAL SYSTEM -
to provide the supporting framework
- to protect the body organs
Bone is a living tissue complete with blood supply and nerves

4. Bone is composed of: Collagen (a protein):
Calcium carbonate & calcium phosphate:
Collagen (a protein):
Makes up 60 – 70 % of bone weight
Provides much of the bone’s stiffness and resistance to pressing or squeezing forces
Water:
Consists of much smaller proportion of water than other body parts
Gives bone it’s characteristic flexibility and contributes to it’s ability to resist pulling and stretching forces
With aging, collagen is lost progressively and bone becomes more brittle

5. WORKSHEET: ANATOMY OF A LONG BONE
Use your text book to complete the worksheet.

6. BONE SHAPE
The shapes of the bones allow them to perform specific functions more effectively

7. SHORT BONES
Include bones of ankle (ie. tarsals) and wrist (ie. carpals)
Serve as good shock absorbers

8. LONG BONES
Include femur of the thigh, humerus of the upper arm and others
Any bone whose length greatly exceeds its diameter
Provide levers for movement

9. FLAT BONES
Include bones of the skull, scapula, ribs, sternum and clavicle
Largely protect underlying organs

10. IRREGULAR BONES Include bones of your face and vertebrae
Bones that cannot be placed in other groups
Fulfil special functions

11. SESAMOID BONES Oval like a pea and found in tendons
Include the patella

12. WORKSHEET