Muscular System

The muscular system moves the body. 
The body has over 600 muscles.
Muscle: an organ that relaxes and contracts to allow movement.

Muscles are either Voluntary or Involuntary

Voluntary – you control

Involuntary – you do not control (examples: heart beating, digestion, respiration)

Connective Tissue – strong flexable tissue

• Tendons – connects muscles to bones
• Ligaments – connects bones to bones at joints
• Cartilage – connective tissue found in many parts of the body. Although it is a tough and flexible material, it is relatively easy to damage. This fine, rubbery tissue acts as a cushion between the bones of joints. 

Skeletal System

Functions of the Skeletal System

1. Produces Blood
   1. Red marrow in long bones produce blood cells
2. Structure and Support:
   1. bones give us shape and supports our bodies
3. Protects internal organs
   1. Cranium protects the brain
   2. rib cage protects the heart and lungs
4. Storage
   1. yellow marrow stores fat
   2. bones store minerals such as calcium that your muscles and nerves need

Types of Joints:

Hinge Joint – back and forth motion
Pivot Joint – Allows rotation
Gliding Joint – sliding and twisting in all directions.
Ball and Socket Joint – Allows for full movement in all directions. Full range of motion.