The Muscular System

Muscles Muscles are organs that relax and contract, and provides the force to move your body parts – Voluntary muscles  muscles you are able to control – Involuntary muscles  muscles you cannot control

Types of Muscle Tissue Skeletal Cardiac Smooth

Skeletal Muscle Move bones Most common type of muscle Tendons  thick bands of tissue that attach muscle to bones Voluntary muscles Contract quickly and tire more easily Look striped, or striated

Cardiac Muscle Found only in the heart Striated (like skeletal muscle)

Smooth Muscles Found in internal organs (like the intestines) Involuntary Contract and relax slowly

Slides of Different Muscle Cells

Movement We can move because pairs of muscles work together – When one muscle of a pair contracts, the other relaxes Muscles always pull Over time, muscles become smaller or larger depending on whether or not they are used Blood carries energy-rich molecules to the muscles so they can do their work

Importance of Exercise Exercise is very important! The stronger your muscles are, the less stress is put on your bones/joints/heart Aerobic exercise, like running/swimming/ biking, are especially helpful strengthen your cardiac muscles Anaerobic exercise, like squats/weight lifting/push ups, help strengthen your skeletal muscles