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1) |
The type of contraction in which the muscle fibers do not shorten is called
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2) |
Receptors for acetylcholine are located on the
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3) |
The following is a list of the events that occur during a muscle contraction.
1. Myosin cross-bridges bind to the actin.
2. The free myosin head splits ATP.
3. Calcium ion is released from the sarcoplasmic reticulum
4. The myosin head pivots toward the center of the sacromere.
5. Calcium ion binds to troponin.
6. The myosin head binds an ATP molecule and detaches from the actin.
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4) |
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5) |
Active sites on the actin become available for binding after
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6) |
After death, muscle fibers run out of ATP and calcium begins to leak from the sacroplasmic reticulum into the sacroplasm. This results in a condition known as
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7) |
Cross-bridges are portions of
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8) |
Which statement about excitation-contraction coupling is INCORRECT?
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9) |
The most important factor in decreasing the intracellular concentration of calcium ion after contraction is
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10) |
Interactions between actin and myosin filaments of the sarcomere are responsible for
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11) |
Which of the following become connected by myosin cross-bridge during muscle contraction?
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12) |
When a muscle is stimulated repeatedly at a high rate, the amount of tension gradually increases to a steady maximum tension. this is called
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13) |
A muscle producing tension that peaks and falls at intermediate stimulus rates is said to be in
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14) |
Each skeletal muscles fiber is controlled by a motor neuron at a single
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15) |
The advantage of having many nuclei in a skeletal muscle fiber is
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16) |
At rest, the tropomyosin molecule is held in place by
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17) |
Why acetylcholine minds to receptors at the motor end plate, the end plate membrane becomes
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18) |
Muscles that move the eyeball have
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19) |
The cytoplasm of the neuromuscular terminal contains vesicles filled with molecules of the neurotransmitter
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20) |
At each end of the muscle, the collagen fibers of the epimysium, and each perimysium and endomysium, come together to form a
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21) |
A patient takes a medication that blocks ACh receptors of skeletal muscle fibers. What is this drug's effect on skeletal muscle contraction?
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22) |
If a second stimulus arrives before the relaxation phase has ended, a second, more powerful contraction occurs. This is called
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23) |
In response to action potentials arriving along the transverse tubules, the sarcoplasmic reticulum releases
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24) |
Put the following structures in order from superficial to deep:
1. muscle fiber
2. perimysium
3.myofibril
4.fascicle
5.endomysium
6. epimysium
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25) |
A resting muscle generates most of its ATP by
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26) |
The repeating unit of a skeletal muscle fiber is the
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27) |
The increase in muscle tension that is produced by increasing the number of active motor units is called
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28) |
Fast muscle fibers can adapt to aerobic metabolism by generating more mitochondria in response to
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29) |
Suppose that you try to pick up an object and discover that it is much heavier than you expected. Which process must occur in the muscle to increase tension so you can pick up the object?
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30) |
Which of these would lead to increased oxygen consumption?
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31) |
The contraction of a muscle exerts a pull on a bone because
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32) |
Synaptic vesicles contain neurotransmitters that are released by __ when the action potential arrives
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33) |
Which type of muscle fibers are best adapted for prolonged contraction such as standing all day?
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34) |
The rapid rise and fall in forces produced by a muscle fiber after a single action potential is
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35) |
After heavy exercise, if energy reserves in a muscle are depleted, __ occurs
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36) |
Each thin filament consists of
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37) |
When comparing slow muscle fibers to fast muscle fibers, slow fibers
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38) |
Which of the following best describes the term Z line?
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39) |
The dense layer of connective tissue that surrounds an entire skeletal muscle is the
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40) |
The action potential is conducted into a skeletal muscle fiber by
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41) |
A fascicle is
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42) |
Which of the following best describes the term titin?
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43) |
Creatine phosphate
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44) |
At rest, active sites on the actin are blocked by
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45) |
The narrow space between the synaptic terminal and the muscle fiber is the
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46) |
Muscular force can be adjusted to match different loads by
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47) |
Triggering of the muscle action potential occurs after
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48) |
How would the lose of acetylcholinesterase from the motor end plate affect skeletal muscle?
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49) |
The plasma membrane of a skeletal muscle fiber is called the
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50) |
A single motor neuron together with all the muscle fibers it innervates is called
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