1. The Muscular System

2. Types of Muscle tissue There are 3 types of muscle tissue Skeletal
Smooth
Cardiac

3. Skeletal Muscle Usually attached to bones
Are involved with voluntary movement
Can be large and very long

4. Smooth Muscle Involuntary control Found in walls of hollow structures
Stomach, blood vessels, and intestines
Help move food through your digestive system and controls blood flow through your circulatory system.

5. Cardiac Muscle Your heart!!
Shares characteristics of both skeletal and smooth muscle cells

6. Muscle Contraction
Skeletal muscle fibers are made up of smaller structures called myofibrils, which are made up of:
Myosin the protein in the thick filament
Actin the protein in the thin filament

7. A muscle contracts when the thin filament (actin) moves over the thick filament (myosin)

8. Control of the Muscle Contraction
Motor neurons connect the CNS to the skeletal muscle cells
The neuromuscular junction is the point of contact between the motor neuron and a skeletal muscle cell
To cause the muscle to contract, acetylcholine (a neurotransmitter) is released

9. The acetylcholine causes the release of Ca ions which trigger the actin and myosin filaments to interact and contract
To stop the contraction the acetylcholine needs to stopped being released and destroyed by an enzyme

10. How Muscles and Bones Interact
Skeletal muscles contract and pull on your bones to produce a movement
Tendons are connective tissue that attach muscle to bones
Joints act as the fulcrum
Muscles work in opposing pairs, when one muscle contracts the other relaxes

11. Opposing muscle pairs

12. Exercise and Health
Regular exercise is important in maintaining muscular strength and flexibility
Exercised muscles will increase in size and strength, help with coordination, efficiency, and flexibility
Unused muscles become weak and decrease in size