Cornell Notes: Skeletal and Muscular Systems
Skeletal System = all 206 bones (more in infants) and connective tissue joining them
5 jobs of your skeletal system:
1. provide shape and support for your body
2. lets you move
3. protects your organs (especially ribs and skull )
4. makes blood cells (in the bone marrow)
5. stores minerals and other materials until your body needs them
Spine (backbone) is made of 26 vertebrae instead of 1 long bone
Four Types of Joints in the skeleton:
Hinge joint: allows forward and backward motion (knee and elbow )
Ball and Socket joint: allows movement in circles (shoulder and hip )
Pivot joint: one bone rotates around another (neck )
Gliding joint: one bone slides over the other, limited side to side motion (wrist)
Connective Tissue:
1. Ligaments connect bones to bones (ACL, MCL)
2. Cartilage covers the ends of bones and protects them from rubbing on each other
3. Tendons: connect bone to muscle
Three Important Facts from the Video Clip that I didn’t already know:
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Summary
Muscular System: There are about 650 muscles in your body
Two general types of muscles (based on control)
Involuntary Muscles: you don’t consciously control them.
Examples: muscles that help you blink, breathe and digest food.
Voluntary Muscles: under your conscious control.
Examples: smiling, running, etc.
Three types of muscle tissue (some are voluntary, some are involuntary)
1. Skeletal muscles are attached to the bones of your skeleton and provide the force that moves your bones. These are voluntary muscles.
2. Smooth muscle is found inside your internal organs and control movements such as food digestion. They are involuntary.
3. Cardiac muscle is found only in your heart. The contracting of these muscles is your heartbeat. Cardiac muscle is involuntary.
Muscle cells “work” when they get messages from the nervous system to contract.
Skeletal muscles have to work in pairs. When one muscle contracts (gets shorter), the other relaxes (gets longer).
Examples: biceps and triceps , hamstring and quadriceps.
Two Important Facts from the Video Clip that I didn’t already know:
1.
2.
Summary