1. Skeletal System 1). Five Major Functions of Skeletal System:
1. Gives shape and support
2. Protects internal organs. (Skull, Rib-cage)
3. Muscles attach to bones.
4. Blood cells are formed in bone marrow.
5. Calcium and Phosphorous storage.

3. Major Organs
A: Skull Connects to the top of the Spine. Made up of cranium (8 plates), and mandible.
Protects the brain, eyes, ear and nose.
B. Spine (Vertebrae) Helps to keep you upright.
linked bones that get smaller as they go down. Between each vertebrae is a
cartilage cushion called a disk.

4. Skull and Spine

5. Rib Cage Note the cartilage : 12 pairs of ribs one pair are “floating”
Link to vertebrae in back, to the sternum in the front.
Protects heart, lungs, and other organs.
Note the cartilage

6. Arms and hands Clavicle and shoulder blade (scapula)
Upper arm is the humerus, the lower arm is the ulna (longer) and radius. 27 bones in wrist and hands (carpels, metacarpals, and phalanges).

7. 27 bones in wrist and hands (carpels, metacarpals, and phalanges).
E: Pelvis: Made of 5 fused vertebrae and hip bones.

8. Legs Legs: Connected to pelvis. Upper leg (femur), kneecap (patella),
Lower-leg (tibia-shinbone, fibula).
26 bones in the feet. (tarsals, metatarsals, phalanges

9. Interesting facts A). Development of Bones:
1). Many bones develop from cartilage as we age.
2). Cartilage cushions bones and allows them to “slide” across each other as they move.
3). Cartilage is 3 times as slick as ice; and acts as a “shock absorber”.
4). Bones are composed of Calcium, Phosphorus, and Magnesium. (Phosphorus is a non-metal).

10. Cartilage

11. Joints B)._Skeletal Joints: 1). All bones that move, use joints.
2). Joints are where two bones are connected close together by ligaments and allow movement.
3). There are six types of joints:
Ball and socket: hip and shoulder.
Hinge: Elbow, fingers, toes, knee….
Pivot joint: upper neck, lower arm..
Saddle joint: base of thumb.
Gliding joint: wrist, ankle.
Ellipsoid joint: base of fingers and toes.

12. Muscular System What makes us move.
There are over 600 muscles in the human body that control all movement.

13. Skeletal Muscle

14. There are three types of muscle:
A). Skeletal: The muscles that attached to bones by tendons, and provide movement. Skeletal muscles are
striated (banded), and are able to be voluntarily controlled by the person. Skeletal muscles react quickly
and tire quickly.
B). Smooth Muscle: Un-striated and involuntary. Are unconsciously controlled by your brain, and control
things like blood pressure, breathing, and digestion.
C). Cardiac Muscles: Found only in the Heart and tightly inter-woven, they are involuntary and never tire (they stop; and you die).

15. Smooth Muscle

16. Heart Muscle

17. Action of Skeletal Muscles
1). Work only by contracting.
2). Muscles always work in pairs, one against the other. (antagonistic).
3). Skeletal muscles are voluntary and are controlled by nerve impulses. Muscles work on what is known as the all or nothing principle…they contract all the way or not at all. The strength of a movement is controlled by how much of a muscle is used. Picking up a paper clip uses very little of the bicep, lifting a child uses all of the biceps muscle.

18. Muscle in Action

19. Injuries to the Skeletal or Muscular Systems
Sprain: a torn or pulled tendon or ligament. Usually pretty painful (sometimes more so than a fracture), with moderate swelling, but still functional and usually heals within a few weeks getting progressively better each day.
Fracture: Any break in a bone. Ranges from a simple fracture (just cracked, but still in place) to a compound fracture (one or both ends of the bone are forced through the skin causing deep lacerations). Most are simple fractures, and they can be almost painless to extremely painful, usually with swelling and bruising. Bones heal by binding back together with new bone cells (remember bones are alive). Most fractures heal between 6 and 8 weeks. Osteoblasts a type of bone cell rebuild bones that are injured and form all bone tissue.
Dislocation: When a bone is forced out of its joint. Very Painful! Generally, the pain is greatly reduced when the bone is put back in place, other than the pain from the bruising that often occurs when a bone dislocated.

20. Sprain

21. Simple Fracture & Compound Fracture

22. Dislocation