Prayer Attendance Homework

Musculoskeletal System Muscular System

Muscles Muscle tissue Bundles of muscle fibers specialized (main function) for contraction. Muscle fibers are joined together by connective tissue.

Types of Muscle Three types of muscle in mammals: Skeletal muscle Smooth muscle Cardiac muscle

Skeletal Muscle Function: voluntary movement Skeletal muscle is innervated by the somatic nervous system.

Questions Part 3-1

Memorize!

Name It! A B G D C E F

Terms myofibrils Filament of a muscle fiber sarcomere Contractile unit of myofibrils sarcoplasmic reticulum Surrounds myofibrils Modified (modified) endoplasmic reticulum that stores calcium ions sarcoplasm Cytoplasm of a muscle fiber sarcolemma Cell membrane of a muscle fiber

Sarcolemma & Transverse Tubules Cell membrane of muscle fiber Propagates an action potential Connected to the transverse tubule (T system) transverse tubule (T system) channels for ion flow throughout the muscle fibers Also propagates an action potential

Questions Part 3-2

Skeletal Muscle Has striations of light and dark bands. Called striated.

Red Fibers vs. White Fibers Skeletal muscle fibers are red or white. Red fibers: Slow twitch fibers High amount of Myoglobin many mitochondria get energy from aerobic respiration Good for fast activity and activity for a long time

Red Fibers vs. White Fibers Fast twitch fibers Anaerobic Has less myoglobin Has less mitochondria Get tired more easily But has greater rate of contraction than red fibers

Questions Part 3-3