1. Musculoskeletal System

4. Bones 206 bones grouped by head, trunk, limbs
Bones are hard solid organ that form part of the skeleton
Continuously renewed
Spongy and compact
4 categories: long, short, flat, irregular

5. Long Bones Thin body(diaphysis), thick extremities(epiphyses)
Mainly compact bone
Centre contains bone marrow (soft, fatty, tissue)
Helps to make blood cells
Limbs ex. Humerus, femur

7. Short Bones
Cubic shape, spongy bone
Wrists & heels

8. - irregular shape, mainly in spine
Flat Bones
Thin, flat, curved, 2 thin layers of compact
with spongy in middle ex. Skull, ribs, sternum,
scapula
Irregular Bones
- irregular shape, mainly in spine

9. Functions of the Bones (RBC, WBC, platelets)
Support- framework, posture,
- supports organs, muscles
Protection- protect internal organs
ex. Skull-brain, Ribs- heart, lungs
Movement-rigid & flexible
- lever(movement of muscles)
Storage- fats, minerals (Ca, P)
Production blood cells- bone marrow
(RBC, WBC, platelets)

10. Joints Function between two or more bones
Some joints contain synovial fluid
Ligaments- fibrous bands, reinforce joints
- connects 2 bones
- cushion of cartilage

11. Mobility of Joints Fixed- bones of skull
Semi-filled- protection of spinal cord,
flexibility of spine
3. Freely moveable- elbow, hip

12. Muscles have the ability to contract causing our bodies or our internal organs to move.

13. Movements Extension and Flexion: - extension increases angle,
while flexion decreases angle
ex. Nodding head

14. 2. Abduction and Adduction: - abduction increases between limb and body - adduction decreases distance ex. Lifting arm out straight

15. Rotation:
- movement of bone around an axis

18. Functions
Movement: limbs (voluntary ex. leg) or organs (involuntary ex. Stomach churning)
Posture Maintenance: muscles contract and release
Joint Stabilization: keeps joints together
Heat release: energy turned to heat to maintain body temp. at 370C

19. Three Types of Muscles
Skeletal: attached to bones by tendons, voluntary, contract (shortens) and relaxes (lengthens), rapid with force over short time
Muscles are bundles of fibres covered in conjunctive tissues

20. Smooth Muscles: walls of some internal organs (stomach etc
Smooth Muscles: walls of some internal organs (stomach etc.), involuntary, move substances from place to place, have endurance but weaker than skeletal

21. Cardiac: muscles of heart, involuntary, similar to skeletal, great strength and endurance, form the ventricles of heart