Ch. 7 The Muscular System

smooth muscle
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Terms in this set (23)
smooth muscle
located in the walls of hollow organs and blood vessels, involuntary, moves materials through organs and regulates blood flow, cylindrical cells with pointed ends, uninucleated, no striations, and not easily fatigued
cardiac muscle
forms the heart wall, uninucleated, striated, tubular, and branched, fibers interlock at intercalated disks, which permit contractions to spread quickly throughout the heart
skeletal muscle
fibers are cylindrical, multinucleate, and striated, voluntary and controlled by the nervous system
endomysium
thin layer of areolar connective tissue, surrounds each skeletal muscle fiber
perimysium
surrounds bundles of muscle fibers (fascicles)
epimysium
layer that surrounds the entire muscle, becomes part of the fascia (separates muscles from each other)
support
movement
maintain a constant body temperature
assists fluid movement
protect bones
stabilize joints
Name 6 functions of the skeletal muscles.
sarcolemma
plasma membrane
sarcoplasm
cytoplasm that contains glycogen that provides energy for muscle contraction and myoglobin which binds oxygen until needed
sarcoplasmic reticulum
endoplasmic reticulum
T (transverse) Tubulesformed by the sarcolemma penetrating into the cell, come into contact with expanded portions of the sarcoplasmic reticulummyofibrilsrun the length of the muscle fibermyosinthick filaments, end in a double globular head that will form a crossbridgeactinthin filamentsI bandcontains only thin filamentsA bandthe center of the sarcomere that contains both thick and thin filamentsH zonethe center of the A band that has only myosin filamentssliding filament theoryoccurs when sarcomeres shorten, thick and thin filaments remain the same length, I band shortens, and the H zone disappearsoriginattachment of a muscle to the immovable boneinsertionattachment of a muscle to the bone that movesprime movermuscle that does most of the work in a movementsynergistmuscles that assist the prime moverantagonistmuscles that work opposite one another to bring about movement in opposite directions