1. Ch. 14.3 Notes The Muscular System

2. There are about 600 muscles in the human body. Muscles have many functions such as: –Keep your heart beating –Pull your mouth into a smile –Move the bones of your skeleton –Expand your chest so you can breathe

3. Types of Muscles There are 3 types of muscle tissue: –Skeletal –Smooth –Cardiac

4. Skeletal Muscle Skeletal muscles are attached to the bones of your skeleton and provide the force that moves your bones. These are the muscles we normally think about: –Biceps –Abs –Gluteus Maximus

5. A tendon is a strong connective tissue that attaches muscle to bone. Remember that ligament was a connective tissue from bone to bone. Skeletal muscles look like they have stripes so sometimes we call them striated muscles. So, Skeletal muscles = Striated muscles

6. Smooth Muscles The inside of many internal organs, such as the stomach and blood vessels, contain smooth muscle. Unlike skeletal muscles, smooth muscle cells are not striped (striated). They react much more slowly and do not tire as easily.

7. Cardiac Muscle THIS IS FOUND ONLY IN YOUR HEART! Cardiac = Heart They are a little like skeletal and smooth muscles. They are striated (like skeletal), but they do not get tired (like smooth). If your heart got tired – YOU WOULD DIE!

9. 2 Categories of Muscles The three types of muscles (skeletal, smooth, and cardiac) can be divided into 2 categories: –Voluntary (You can move it when you want to) –Involuntary (It moves all by itself without thinking)

10. Voluntary or Involuntary? Heart Biceps Abs Diaphragm (lungs for breathing) Eye lids Toes Stomach Blood Vessels

11. Muscles at Work Because muscle cells can only CONTRACT (get shorter), not extend, skeletal muscles must work in pairs. While one muscle contracts, the other muscle in the pair relaxes to its original length.

12. Guess the Pair Bicep Abs Triceps Gluteus Maximus Hamstring Calf

13. Muscular Strength and Flexibility Regular exercise is important for maintaining both muscular strength and flexibility. Exercise makes individual muscles cells grow in size. As a result, the whole muscle becomes thicker. Stretching warms up the muscles and keeps them limber to help prevent injuries.

15. Injured? Sometime, even if you are careful, you can get injured. A muscle strain, or pulled muscle, can occur when muscles are overworked or overstretched. Tendons can also be overstretched or partially torn. After a long period of exercise, skeletal muscles can cramp.

16. A muscle cramp is when the entire muscle contracts strongly and stays contracted! It is important to follow your doctors advise if you have a muscle or connective tissue injury. Sometimes they are so bad you have to have surgery.