1. Muscular & Skeletal Systems
a.k.a. The Musculoskeletal System

2. The Skeletal System

3. Bones Provide support for the body Form the body’s shape
Very lightweight, but strong enough to support body weight
206 bones in the body

4. Inside a Bone Compact bone – the solid, hard outside part of the bone
Cancellous bone – spongy, inside the compact bone
Bone marrow – inside of the bone; where most of the blood cells are made (make a connection to another system)

5. Between the Bones
Ligaments – long, fibrous straps that connect bones to other bones
Cartilage – flexible, rubbery substance; supports bones and protects them when they rub against each other

6. Types of Bones Short bones – chunky, wide bones; feet and wrists
Long bones – a bone that is significantly longer than it is wide; arm and leg bones
Flat bones – plate-like bones, have a flat shape; ribs and shoulder blades
Irregular bones – have odd shapes and don’t fit into any other category, vertebrae

7. The Muscular System

8. Muscles Muscles pulls on the joints, allowing us to move
Help the body perform other functions necessary for life, such as digesting food (make another connection here)
More than 650 muscles – half of a person’s body weight
3 types of muscle…

9. Skeletal Muscle
attached to bone, mostly in the legs, arms, abdomen, chest, neck, and face
Striated muscles (made up of fibers that have horizontal stripes)
Hold the skeleton together, give the body shape and help it with everyday movements
Voluntary (you can control their movements)

10. Smooth Muscle
Found in the stomach and small intestines; blood vessels (more connections here)
Looks smooth, not striated
Involuntary (you don’t control the movements, they are controlled by the nervous system automatically)

11. Cardiac Muscle Found in the heart
walls of the heart's chambers are composed almost entirely of muscle fibers
Involuntary (you don’t control the movements, they are controlled by the nervous system automatically)

12. Joints Allow our bodies to move in many ways
Classified by their range of movement (3 types)
Immovable (fibrous) joints don’t move
dome of the skull
Teeth in the jaw bone
Partially movable (cartilaginous) joints move a little
Spine (linked by cartilage)

13. Freely movable (synovial) joints
Move in many directions
Filled with synovial fluid
Hinge joints move in one direction
Elbow, knee
Pivot joints allow a rotating or twisting motion
Neck, wrist
Ball-and-socket joints allow the greatest freedom of movement
Hip, shoulder

14. Movement Tendons – connects bones to the skeletal muscles
Muscle cells – only cells in the body that can shorten (contract)
Flexor – muscle that causes a joint to bend when it contracts
Extensor – muscle that causes a joint to straighten when it contracts

15. For more information check out…
our_body/body_basics/bones _muscles_joints.html#