2. Chapter 15 By: Harold Hoy The human body

3. Your body is made up of trillions of cells which are organized into tissues. A tissue is a group of similar cells that perform the same function.

4. Muscle tissue- the only kind of tissue in your body that knows how to contract or shorten. By contracting and thus pulling on bones one type of muscle tissue knows how to make your body move.

5. Nerve Tissue- carries messages back and forth between the brain and spinal cord and every other part of your body.

6. The skeletal System The bodies living frame work. This complicated structure contains more than 200 bones.

7. The skeletal system has 5 important functions: –It provides shape and support, allows movement, protects organs and tissue, stores certain materials, and produces blood cells.

8. Development of bones: –Many bones are formed from a type of connective tissue called cartilage. –Cartilage is a very hard, stiff, jelly like material.

9. The muscular System In the human body there are three types of muscular tissues: –Skeletal muscle –Smooth muscle –Cardiac muscle

10. Each type of muscle tissue has a characteristic structure and function. The muscle that attaches to and moves bones is called skeletal muscle. Smooth muscle- does not have bands, also called involuntary muscle. Cardiac muscle- is found only in the heart, branches out in many directions.

11. In order for skeletal muscle to bring about any kind of movement, the action of two muscles or two groups of muscles is needed. Skeletal muscles contract only when the receive a message from a nerve to do so. The nerve carries messages from the brain to the spinal chord to the muscles signaling them to contract.

12. The endThe end