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| 1 | |
A skeletal muscle contains many fascicles of _________ bound together by _________ connective tissue. |
| | A) | muscle fibers; fibrous |
| | B) | myosin filaments; fibrous |
| | C) | muscle fibers; loose |
| | D) | myofilaments; fibrous |
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| 2 | |
Contraction of myofibrils results from _________ cross-bridges pulling _______ filaments to the center of a sarcomere. |
| | A) | myosin; muscle fibers |
| | B) | myosin; myofibrils |
| | C) | actin; myosin |
| | D) | myosin; actin |
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| 3 | |
A motor neuron and the muscle fibers it controls constitute a__________, which contains _________ muscle fibers where precise muscle control is required. |
| | A) | motor fascicle; very few |
| | B) | muscle; many |
| | C) | motor unit; very few |
| | D) | motor unit; many |
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| 4 | |
A muscle fiber is stimulated to contract when receptors on the _________ bind with acetylcholine released into the synaptic cleft by the axon tip of the ________. |
| | A) | motor neuron; sarcolemma |
| | B) | sarcolemma; motor neuron |
| | C) | sarcomere; motor neuron |
| | D) | synaptic vesicles; motor neuron |
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| 5 | |
The accumulation of lactic acid during strenuous muscle activity results from a deficiency of |
| | A) | pyruvic acid. |
| | B) | glucose. |
| | C) | ADP. |
| | D) | oxygen. |
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| 6 | |
An all-or-none response to a threshold stimulus is characteristic of |
| | A) | individual muscle fibers. |
| | B) | small muscles. |
| | C) | large muscles. |
| | D) | None of these choices. |
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| 7 | |
A muscle’s motor units are activated by different thresholds of stimulation, which enables a muscle to exhibit |
| | A) | sustained contractions. |
| | B) | graded contractions. |
| | C) | latent contractions. |
| | D) | all-or-none responses. |
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| 8 | |
When a muscle spanning a joint contracts, it pulls the ________ toward the ________. |
| | A) | insertion; origin |
| | B) | origin; insertion |
| | C) | smaller bone; larger bone |
| | D) | larger bone; smaller bone |
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| 9 | |
Two muscles of mastication are the _________ and _________. |
| | A) | masseter; buccinator |
| | B) | masseter; platysma |
| | C) | masseter; temporalis |
| | D) | masseter; zygomaticus |
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| 10 | |
The superficial muscle that originates on the pubic bone and inserts on the tip of the sternum and costal cartilages is the |
| | A) | rectus abdominis. |
| | B) | external oblique. |
| | C) | internal oblique. |
| | D) | transversus abdominis. |
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| 11 | |
The muscle that abducts and extends the humerus is the |
| | A) | latissimus dorsi. |
| | B) | pectoralis major. |
| | C) | coracobrachialis. |
| | D) | deltoid. |
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| 12 | |
The muscle that extends the forearm is the |
| | A) | brachialis. |
| | B) | triceps brachii. |
| | C) | brachioradialis. |
| | D) | biceps brachii. |
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| 13 | |
The muscle that extends and rotates the femur laterally is the |
| | A) | psoas major. |
| | B) | adductor magnus. |
| | C) | gluteus maximus. |
| | D) | gluteus medius. |
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| 14 | |
Select the three muscles that compose the hamstrings and flex the leg. |
| | A) | Biceps femoris, Rectus femoris, Semitendinosus |
| | B) | Biceps femoris, Semimembranosus, Semitendinosus |
| | C) | Biceps femoris, Gracilis, Sartorius |
| | D) | Biceps femoris, Vastus medialis, Semitendinosus |
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| 15 | |
The ________ originates on the condyles of the femur, inserts on the calcaneus, flexes the leg, and plantar flexes the foot. |
| | A) | gastrocnemius |
| | B) | soleus |
| | C) | peroneus longus |
| | D) | tibialis anterior |
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