Term
| what is the main function of the muscle? |
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Definition
| contraction and shortening |
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Term
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Definition
| skeletal or smooth muscle cells |
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Term
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Definition
| skeletal muscle is called this because of the obvious stripes |
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Term
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Definition
| muscle type subject to conscious control (skeletal muscle) |
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Term
| what are skeletal muscles? |
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Definition
| muscles that attach to the body's skeleton |
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Term
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Definition
| a delicate connective tissue sheath that encloses each muscle fiber |
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Term
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Definition
| a coarse fibrous membrane that wraps the muscle fibers |
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Term
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Definition
| a bundle of muscle fibers |
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Term
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Definition
| an even tougher "overcoat" of connective tissue (covers the entier muscle) |
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Term
| what do the epimysia turn into? |
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Definition
| they blend into the strong, cordlike tendons or into sheetlike aponeuroses |
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Term
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Definition
| cord or band of inelastic tissue connecting a muscle to bone |
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Term
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Definition
| sheetlike attachment that binds muscles indirectly to bones, cartilage, or connective tissue coverings |
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Term
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Definition
| this type of muscle has no striations and is involuntary (stomach and bladder) |
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Term
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Definition
| a type of involuntary striated muscle found solely in the heart |
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Term
| what are intercalated discs? |
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Definition
| these are special junctions that join the branching cells of the cardiac muscle fibers |
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Term
| what are the functions of skeletal muscles? |
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Definition
| they maintain posture, stabilize joints, and generate heat (produce movement) |
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Term
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Definition
| long ribbon-like organelles that nearly fill the cytoplasm |
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Term
| what gives muscles their striped appearance? |
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Definition
| the alternating light (I) and dark (A) bands along the length of the perfectly aligned myofibrils |
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Term
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Definition
| chains of tiny contractile units |
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Term
| what are the two types of myofilaments? |
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Definition
| the thin (actin) filaments and the thick (myosin) filaments |
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Term
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Definition
| these are when the myosin heads link the thick and thin filaments together during a contraction |
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Term
| what is the sarcoplasmic reticulum? |
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Definition
| a specialized smooth endoplasmic reticulum that surrounds each of the myofibrils |
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Term
| what are the four special functional properties of muscles? |
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Definition
| excitability, contractility, extensibility, and elasticity |
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Term
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Definition
| the ability to receive and respond to a stimulus (responsiveness or irritability) |
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Term
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Definition
| the ability to shorten (forcibly) when adequately stimulated |
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Term
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Definition
| the ability of muscle cells to be stretched |
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Term
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Definition
| their ability to recoil and resume their resting length after being stretched |
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Term
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Definition
| one neuron and all the skeletal muscle cells it stimulates |
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Term
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Definition
| long, threadlike extensions of the neuron (nerve fiber) |
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Term
| what is the neurotransmitter? |
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Definition
| this chemical is released when a nerve impulse reaches the axon terminals |
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Term
| what is acetylcholine (ACh)? |
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Definition
| the specific neurotransmitter that stimulates skeletal muscle cells |
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Term
| what is the action potential? |
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Definition
| electrical current caused by an "upset" or inbalance of Na+ ions. |
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