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| 1 | |
______ surrounds each muscle fasciculus, whereas ______ surrounds each muscle fiber. |
| | A) | Epimysium, perimysium |
| | B) | Perimysium, endomysium |
| | C) | Epimysium, endomysium |
| | D) | Endomysium, perimysium |
| | E) | Endomysium, epimysium |
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| 2 | |
The basic structural and functional unit of skeletal muscle is the |
| | A) | fiber. |
| | B) | fasciculus. |
| | C) | myofibril. |
| | D) | sarcomere. |
| | E) | whole muscle. |
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| 3 | |
Which of these units contains overlapping actin and myosin myofilaments? |
| | A) | A band |
| | B) | H zone |
| | C) | I band |
| | D) | M line |
| | E) | Z disk |
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| 4 | |
Which of these is NOT a part of the actin myofilament? |
| | A) | actin |
| | B) | sarcolemma |
| | C) | tropomyosin |
| | D) | troponin |
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| 5 | |
Each muscle cell is a |
| | A) | fasciculus. |
| | B) | sarcomere. |
| | C) | fiber. |
| | D) | myofibril. |
| | E) | myofilament. |
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| 6 | |
To establish the resting membrane potential, |
| | A) | sodium ions diffuse into the cell. |
| | B) | sodium ions diffuse out of the cell. |
| | C) | potassium ions diffuse into the cell. |
| | D) | potassium ions diffuse out of the cell. |
| | E) | large negative molecules diffuse out of the cell. |
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| 7 | |
Before being released from the axon of a neuron, acetylcholine is stored in the |
| | A) | synaptic vesicles. |
| | B) | synaptic cleft. |
| | C) | muscle fiber. |
| | D) | postsynaptic membrane. |
| | E) | sarcoplasmic reticulum. |
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| 8 | |
During the process of muscle contraction, calcium ions bind to the |
| | A) | presynaptic terminal. |
| | B) | sarcolemma. |
| | C) | synaptic vesicles. |
| | D) | tropomyosin molecules. |
| | E) | troponin molecules. |
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| 9 | |
During muscle contraction, which of these processes requires ATP? |
| | A) | Calcium ions are moved back to the sarcoplasmic reticulum. |
| | B) | Cross-bridges are released. |
| | C) | Heads of the myosin myofilaments are bent toward the center of the sarcomere. |
| | D) | Heat is released. |
| | E) | All of these. |
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| 10 | |
Even though each muscle fiber responds in all-or-none fashion, a whole muscle can contract with varying force because of |
| | A) | different threshold values. |
| | B) | total tetanus of the muscle. |
| | C) | recruitment of additional motor units. |
| | D) | rigor mortis. |
| | E) | the lag phase of contraction. |
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| 11 | |
Anaerobic respiration |
| | A) | produces 36-38 ATP per glucose molecule. |
| | B) | produces an oxygen debt. |
| | C) | occurs in resting muscles or muscles undergoing long-term exercise. |
| | D) | can use fatty acid to produce ATP. |
| | E) | All of these. |
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| 12 | |
Fast-twitch muscle fibers |
| | A) | are more resistant to fatigue than slow-twitch fibers. |
| | B) | have a richer blood supply than slow-twitch fibers. |
| | C) | have a larger amount of stored glycogen than slow-twitch fibers. |
| | D) | have more mitochondria than slow-twitch fibers. |
| | E) | have more myoglobin than slow-twitch fibers. |
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| 13 | |
Two muscles that are antagonists are the |
| | A) | rectus femoris and vastus lateralis. |
| | B) | vastus medialis and vastus intermedius. |
| | C) | adductor longus and vastus lateralis. |
| | D) | rectus femoris and semimembranosus. |
| | E) | gluteus maximus and semitendinosus. |
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| 14 | |
If a woman raised her arms straight out pointing right and left, level with her shoulders, she mostly used her |
| | A) | biceps brachii muscles. |
| | B) | latissimus dorsi muscles. |
| | C) | pectoralis major muscles. |
| | D) | deltoid muscles. |
| | E) | All of these. |
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| 15 | |
Which of these muscles flexes both the arm and the forearm? |
| | A) | biceps brachii. |
| | B) | brachialis. |
| | C) | deltoid. |
| | D) | latissimus dorsi. |
| | E) | triceps brachii. |
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| 16 | |
All of the following are functions of the muscular system EXCEPT: |
| | A) | Maintenance of posture |
| | B) | Production of body heat |
| | C) | Communication |
| | D) | Storage of mineral and fat |
| | E) | Constriction of organs and vessels |
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| 17 | |
Which of the following is not a functional characteristic of skeletal muscle? |
| | A) | Contractility |
| | B) | Excitability |
| | C) | Extensibility |
| | D) | Elasticity |
| | E) | All of these are characteristics of skeletal muscle. |
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| 18 | |
As the action potential arrives at a presynaptic terminal, the event that causes the release of acetylcholine from synaptic vesicles into the synaptic cleft is: |
| | A) | Ca++ ions entering the presynaptic terminal |
| | B) | Na+ ions entering the presynaptic terminal |
| | C) | Ca++ ions entering the postsynaptic cell |
| | D) | Na+ ions entering the postsynaptic cell |
| | E) | Ca++ ions exiting the presynaptic terminal |
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| 19 | |
The rotator cuff consists of all of these muscles EXCEPT: |
| | A) | teres major. |
| | B) | teres minor. |
| | C) | subscapularis. |
| | D) | supraspinatus. |
| | E) | infraspinatus. |
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| 20 | |
In _________ contractions the amount of tension increases during the contraction process, but the length of the muscle does not change. |
| | A) | isotonic |
| | B) | isometric |
| | C) | concentric |
| | D) | eccentric |
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