Functions of the Muscular System

1. The muscular systemis the body system that consists of muscles that provide motion and maintain posture.

2. Functions of the Muscular System • Movement - all movements of body are a result of muscle contraction • Maintaining posture • Stabilizing joints – reinforce and stabilize the joints of the skeleton

3. Two Groups of Muscles 1. Voluntary muscle - a muscle a person can control • Muscles in arms and legs that help you move 2. Involuntary muscle– a muscle that functions without a person’s control • Muscles in your stomach and other internal organs

4. Types of Muscle Tissue • Smooth muscle - involuntary muscle tissue found in many internal organs • Skeletalmuscle– voluntary muscle tissue that is attached to bone • Cardiac muscle– specialized muscle tissue found only in the heart

5. Muscle Movement • Skeletal muscles work in pairs to move your body—one muscle in the pair contracts and shortens, while the other relaxes and lengthens • Muscles cannot push, they can only pull so they work in pairs so they can pull in different or opposite directions • Tendon – tough tissue fiber that attaches muscles to bones

6. Head and Neck Muscles • Frontalis – covers frontal bone (forehead), raises eyebrows, wrinkles skin of forehead • Sternocleidomastoid– side of neck, flex (bend) your neck • Trapezius– diamond shape behind neck, moves shoulder, extends neck • Deltoid– triangle shaped muscles of the shoulder, shrugging shoulders, moves humerus • Latissimusdorsi– middle part of back, moves humerus

7. Trunk Muscles • Pectoralis major - fan- shaped muscle covering upper part of chest • Rectus abdominis- torso, stomach area, bends the torso and flexes vertebral column

8. Arm/Shoulder Muscles • Biceps - front of upper arm, bends arm, flexes elbow • Triceps - back of upper arm, straighten arm, extends elbow

9. Hip/Leg Muscles • Gluteus maximus– buttocks • Quadriceps (quads) – front of thigh, extends knee • Hamstrings– back of thigh, bend/flex knee • Gastrocnemius- calf muscle, pull up on heel, point toes • Achilles Tendon - connects the calf muscle to the heel bone

12. How to Keep your Muscular System Healthy • Discontinue exercise if you have a muscle injury • Warm up and stretch before you exercise • Exercise different muscle groups regularly • Maintain your desirable weight • Bend at the knees and keep your back straight when lifting heavy objects • Select foods and beverages containing carbohydrates and proteins for energy and muscle development • Sleep on a firm mattress