front 1 A single somatic motor neuron and all of the muscle fibers it stimulates is known as a _________ . | back 1 motor unit |
front 2 The wasting away of muscle due to lack of use is known as [a] while the replacement of skeletal muscle fibers with scar tissue is known as [b]. | back 2 a. muscular atrophy
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front 3 The synaptic end bulbs of somatic motor neurons contain synaptic vesicles filled with the neurotransmitter _________ . | back 3 acetycholine |
front 4 The ability of muscle cells to respond to stimuli and produce electrical signals is known as excitability. | back 4 true |
front 5 The sequence of events resulting in skeletal muscle contraction are (a) generation of a nerve impulse, (b) release of the neurotransmitter acetylcholine, (c) generation of a muscle action potential, (d) release of calcium ions from the sarcoplasmic reticulum, (e) calcium ion binding to the troponin-tropomyosin complex, (f) power stroke with actin and myosin binding and release. | back 5 true |
front 6 In muscle physiology, the latent period refers to | back 6 a brief delay that occurs between application of a stimulus and the beginning of contraction |
front 7 Which of the following muscle proteins and their descriptions are mismatched? | back 7 titin: regulatory protein that holds troponin in place |
front 8 During muscle contraction all of the following occur except | back 8 the thick filaments slide inward toward the M line |
front 9 Which of the following is not true concerning muscle fiber length–tension relationships? | back 9 If sarcomeres shorten, the tension in them increases |
front 10 Which of the following are sources of ATP for muscle contraction? (1) creatine phosphate, (2) glycolysis, (3) anaerobic cellular respiration, (4) aerobic cellular respiration, (5) acetylcholine | back 10 1, 2, 3, and 4 |
front 11 What would happen if ATP were suddenly unavailable after the sarcomere had begun to shorten? | back 11 The myosin heads would be unable to detach from actin. |
front 12 sheath of areolar connective tissue that wraps around individual skeletal muscle fibers | back 12 endomysium |
front 13 dense irregular connective tissue that separates a muscle into groups of individual muscle fibers | back 13 perimysium |
front 14 bundles of muscle fibers | back 14 fascia |
front 15 the outermost connective tissue layer that encircles an entire skeletal muscle | back 15 tendon (synovial) sheath |
front 16 dense irregular connective tissue that lines the body wall and limbs and holds functional muscle units together | back 16 fascia |
front 17 a cord of dense regular connective tissue that attaches muscle to the periosteum of bone | back 17 tendon |
front 18 elongated muscle cell | back 18 muscle fiber |
front 19 areolar and adipose connective tissue that separates muscle from skin | back 19 subcutaneous layer |
front 20 connective tissue elements extended as a broad, flat layer | back 20 aponeurosis |
front 21 a two-layer tube of fibrous connective tissue enclosing certain tendons | back 21 tendon (synovial) sheath |
front 22 synapse between a motor neuron and a muscle fiber | back 22 neuromuscular junction |
front 23 invaginations of the sarcolemma from the surface toward the center of the muscle fiber | back 23 transverse (T) tubules |
front 24 myoblasts that persist in mature skeletal muscle | back 24 satellite cells |
front 25 plasma membrane of a muscle fiber | back 25 sarcolemma |
front 26 oxygen-binding protein found only in muscle fibers | back 26 myoglobin |
front 27 Ca2+-storing tubular system similar to smooth endoplasmic reticulum | back 27 sarcoplasmic reticulum |
front 28 the contracting unit of a skeletal muscle fiber | back 28 sarcomere |
front 29 middle area in the sarcomere where thick and thin filaments are found | back 29 A band |
front 30 area in the sarcomere where only thin filaments are present but thick filaments are not | back 30 I band |
front 31 separates the sarcomeres from each other | back 31 Z disc |
front 32 area of only thick filaments | back 32 H zone |
front 33 cytoplasm of a muscle fiber | back 33 sacroplasm |
front 34 composed of supporting proteins holding thick filaments together at the H zone | back 34 M line |
front 35 has fibers joined by intercalated discs | back 35 cardiac |
front 36 thick and thin filaments are not arranged as orderly sarcomeres | back 36 smooth |
front 37 uses satellite cells to repair damaged muscle fibers | back 37 skeletal |
front 38 striated | back 38 skeletal and cardiac |
front 39 contraction begins slowly but lasts for long periods | back 39 smooth |
front 40 has an extended contraction due to prolonged calcium delivery from both the sarcoplasmic reticulum and the interstitial fluid | back 40 cardiac |
front 41 does not exhibit autorhythmicity | back 41 skeletal |
front 42 uses pericytes to repair damaged muscle fibers | back 42 smooth |
front 43 uses troponin as a regulatory protein | back 43 skeletal and cardiac |
front 44 can be classified as single-unit or multiunit | back 44 smooth |
front 45 can be autorhythmic | back 45 cardiac and smooth |
front 46 uses calmodulin as a regulatory protein | back 46 smooth |