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27 Cards in this Set
- Front
- Back
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What are the functions of muscles? |
Locomotion Respiration Digestion Parturition Blood/lymph circulation Swallowing Body heat generation |
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What are the properties of muscles? |
Contractility (contract/shorten) Excitability (receive/respond to stimulus) Extensibility (ability to be stretched) Elasticity (ability to return to original shape) |
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What are the types of muscle? |
Skeletal (40% of body) Cardiac Smooth cardiac + smooth make up 10% of body |
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What type of muscle is striated? |
Skeletal and cardiac |
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What type of muscle is involuntary? |
Cardiac and smooth |
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What type of muscle has central located nuclei? |
Cardiac and smooth |
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What type of muscle has peripherally located nuclei? |
Skeletal |
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What type of muscle contracts rapidly? |
Cardiac and skeletal |
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Where is skeletal muscle located? |
trunk, extremities, head/neck |
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Where is smooth muscle located? |
viscera, blood vessels |
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What does skeletal muscle do? |
provides support for skeleton and body movement Attaches to bones by tendons Stimulated by a motor nerve (voluntary control) |
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What is movement a result of? |
Contraction of muscle across a moveable joint (joints having one or more muscles on either side) |
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What is the epimysium? |
connective tissue sheath surrounding each muscle |
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What is the fasicle? |
Small bundle/cluster of muscle fibers (cells) |
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What is the perimysium? |
connective tissue extensions from epimysium surrounding each fasicle |
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What is endomysium? |
connective tissue extension from perimysium surrounding muscle fibers and attached to the sarcolemma |
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What is the sarcolemma? |
Thin cell membrane enclosing muscle fiber (fuses with tendon fibers to form tendons) **at the end of the muscle fiber it connects muscle to bone** |
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What are the muscle fibers? |
alongated shape, contractile unit pull is transmitted by endomysium, preimysium and epimysium to tendon/aponeurosis attached to bone |
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What are the two types of muscle fibers? |
Red (type 1-slow twitch-pigeons, horses--oxidat.) White (type 2-fast twitch-chickens--glycotic) |
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How many myofibrils are in each muscle fiber? |
several hundred to several thousand |
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What is a sarcomere? |
Basic contractile unit found between Z lines (myofilaments=these give rise to striations) |
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What are the myofilaments? |
composed of actin and myosin, the filaments partially interdigitate causing dark and light bands |
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What do the different bands/zones mean? |
I band= light (isotropic to polarized light) A band = dark (anisotropic to polarized light) H zone = light zone M line = inside H zone Z line= end of actin (transversely bisects I band) |
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What are the different organelles of the muscle fiber? |
Sarcoplasmic reticulum Mitochondria T-tubules |
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What is the SR responsible for? |
muscle contraction regulates Ca storage, release and uptake bigger in faster contracting fibers (white) |
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What are the mitochondria responsible for? |
supply myofibrils with energy (ATP) lie in parallel to myofibrils more mitochondria in slow fibers (red) large in numbers in muscle* |
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What are the T tubules responsible for? |
Allow membrane of fiber to carry depolarization of action potential to interior of fiber Transverse to myofibril Have extracellular fluid Invaginations of sarcolemma |
