Term
| what are the three types of muscle? |
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Definition
| skeletal, cardiac, and smooth |
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Term
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Definition
| striated, long parallel arrangement, and multiple peripheral nuclei |
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Term
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Definition
| striated, branched cells, central nucleus, and intercalated discs |
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Term
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Definition
| fusiform, central "cork screw nucleus" |
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Term
| the fusion of ______ forms skeletal muscles |
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Definition
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Term
| what are satellite cells? |
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Definition
| myeloblasts that remain as stem cells |
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Term
| True or false: under different conditions satellite cells can change to muscle cells. |
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Definition
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Term
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Definition
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Term
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Definition
| the muscle fiber cytoplasm |
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Term
| what is the sarcoplasmic reticulum? |
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Definition
| specialized muscle endoplasmic reticulum |
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Term
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Definition
| connective tissue surrounding individual muscle cells, composed of reticular fiber and external basal lamina |
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Term
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Definition
| thicker connective tissue that surrounds and defines fascicles (functional bundles of muscle fibers) |
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Term
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Definition
| dense connective tissue that surrounds the entire muscle (a collection of fasicles) |
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Term
| strength of a muscle and the direction of its pull are determined partly by? |
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Definition
| the orientation of its fascicles |
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Term
| what is reflexive muscle contraction? |
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Definition
| not voluntarily controlled |
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Term
| what is tonic muscle contraction? |
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Definition
| slight contraction that gives muscle firmness, assisting stability of joints and posture |
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Term
| what are the 2 types of phasic muscle contraction? |
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Definition
|
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Term
| what is isometric muscle contraction? |
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Definition
| muscle length does not change |
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Term
| what is isotonic muscle contraction? |
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Definition
|
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Term
| how are skeletal muscles characterized? |
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Definition
| by the speed of contraction and metabolic activity |
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Term
| describe type I skeletal muscle fibers |
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Definition
| red, slow twitch, not easily fatigued, high myoglobin content, many mitochondria and high in oxidative enzymes, slow myosin ATPase reaction velocity; they need to be able to be active for long periods of time, they are aerobic |
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Term
| where do type I skeletal muscle fibers predominate? |
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Definition
| deep back muscles and other postural muscles to maintain upright posture, soleus of the calf |
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Term
| describe type IIb skeletal muscle fibers |
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Definition
| white, fast twitch, power and rapid contraction but easily fatigued, low myoglobin content, few mitochondria and low in oxidative enzymes, very fast myosin ATPase reaction velocity |
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Term
| describe type IIa skeletal muscle fibers |
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Definition
| intermediate, fast oxidative, they make up fast twitch fatigue resistant motor units that have intermediate characteristics from those described above |
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Term
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Definition
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Term
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Definition
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Term
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Definition
| inhibits actin-myosin binding |
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Term
| what is myosin composed of? |
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Definition
| 2 identical heavy chains and 2 pairs of light chains |
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Term
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Definition
| the region between two successive Z lines; the sarcomere is the functional unit of striated muscle |
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Term
| describe the sliding filament model |
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Definition
| thin filaments slide past thick filaments, I and H bands shorten, sarcomere shortens, Z discs are drawn close, A band does not change in length |
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Term
| mutations in the dystrophin gene cause? |
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Definition
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Term
| absence of dystrophin causes? |
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Definition
| Duchenne's muscular dystrophy; causes progressive muscle weakness in boys |
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Term
| what is a sarcoplasmic reticulum? |
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Definition
| specialized network of endoplasmic reticulum around the myofibrils. Acts as a calcium sink |
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Term
| where is the 'triad' located in skeletal muscle? |
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Definition
|
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Term
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Definition
| act to rapidly spread depolarization throughout the muscle fiber so that there is widespread release of calcium from the sarcoplasmic reticulum allowing for uniform contraction of the muscle fibers |
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Term
| axon terminals contain synaptic vesicles filled with what neurotransmitter? |
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Definition
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Term
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Definition
| a single motor axon and all the muscle fibers it innervates; can be large for muscles that require course movements |
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Term
| what is the autoimmune disease in which antibodies are made to the ACh receptor? |
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Definition
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Term
| what is the most common motor neuron disease? |
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Definition
| ALS (Lou Gehrig's disease) |
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Term
| what type of receptor is the muscle spindle? |
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Definition
|
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Term
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Definition
| centrally positioned nuclei, the fibers are branched, have intercalated discs, t tubules are larger than in skeletal muscle and are located at a Z disc, have large mitochondria |
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Term
| which type of muscle has the 'diad' format? |
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Definition
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Term
| what is found in the intercalated disc? |
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Definition
| macula adherens, gap junctions and fascia adherens |
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Term
| when there is a death of cardiac muscle due to prolonged ischemia (lack of blood) what occurs? |
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Definition
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Term
| describe smooth muscle cells |
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Definition
| elongated, spindle shaped cells with a single centrally located nucleus, found in the walls of hollow organs and blood vessels |
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Term
| what are cytoplasmic densities/dense bodies? |
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Definition
| proteins which anchor thin filaments and intermediate filaments, analogous to z lines in striated muscle |
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