Term
Because skeletal muscle contractions demand large quantities of ATP, skeletal muscles have:
a.) a rich nerve supply
b.) a rich vascular supply
d.) little need for oxygen
e.) a large concentration of tissue hemoglobin |
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Definition
| b.) a rich vascular supply |
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Term
Physical evidence that supports the sliding filament theory of muscle contraction includes:
a.) decreased distance between Z lines during contraction
b.) increased width of the H band during contraction
c.) increased width of the I band during contraction
d.) decreased width of the A band during contraction
e.) an increased distance between Z lines during contraction |
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Definition
| a.) decreased distance between Z lines during contraction |
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Term
When myosin cross-bridges bind to the active sites on actin,
a.) ATP is hydrdolyzed
b.) they pivot toward the M-lines
c.) the sarcomere strengthens
d.) muscle relaxation occurs
e.) the I band moves closer to the Z line |
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Definition
| b.) they pivot toward the M-line |
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Term
Which of the following is greater?
a.) the concentration of calcium ion in the sarcoplasm of a resting muscle
b.) the concentration of calcium ion in the sarcoplasmic reticulum of a resting muscle |
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Definition
| b.) the concentration of calcium ion in the sarcoplasmic reticulum of a resting muscle |
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Term
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 towards the center of the sarcomere
5.) calcium ion binds to troponin
6.) the myosin head binds an ATP molecule and detaches from the actin
The correct sequence of these events is:
a.) 1, 3, 5, 4, 6, 2
b.) 5, 1, 4, 6, 2, 3
c.) 3, 5, 1, 2, 4, 6
d.) 3, 5, 1, 4, 6, 2
e.) 1, 4, 6, 2, 3, 5 |
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Definition
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Term
| After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as: |
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Definition
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Term
When acetylcholine binds to receptors at the motor end plate, the muscle membrane becomes:
a.) more permeable to sodium ions
b.) less permeable to sodium ions
c.) more permeable to potassium ions
d.) less permeable to potassium ions
e.) repolarized |
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Definition
| a.) more permeable to sodium ions |
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Term
In which of the following would the ratio of motor neurons to muscle fibers be the greatest?
a.) large muscles of the upper arm
b.) postural muscles of the back
c.) muscles that control the eye
d.) leg muscles
e.) the calf muscles |
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Definition
| c.) muscles that control the eye |
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Term
Which of the following activities would employ isometric contractions:
a.) flexing the forearm
b.) chewing food
c.) maintaining an upright posture
d.) running
e.) writing |
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Definition
| c.) maintaining an upright posture |
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Term
A cramp can occur when
a.) the muscle is fatigued
b.) there is irritation of teh motor neuron or of the muscle fiber membrane
c.) there is chemical or physical damage to the sarcolemma
d.) both a and b only
e.) all of the above |
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Definition
DOUBLE CHECK ANSWER-->
a.) the muscle is fatigued |
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Term
How would an elevated level of thyroid hormone in the body affect skeletal muscles? It would:
a.) stimulate atrophy
b.) stimulate hypertrophy
c.) stimulate metabolism
d.) decrease heat prodution by muscle tissue
e.) cause an increase in muscle mass |
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Definition
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Term
How would a drug that competes with acetycholine for receptors at the motor end plate affect skeletal muscle? It would
a.) make the muscles more excitable
b.) produce uncontrolled muscle spasms
c.) causes spastic paralysis (muscles are contracted and cannot relax)
d.) cause flaccid paralysis (muscles are relaxed and cannot contract)
e.) have no effect on skeletal muscle |
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Definition
| d.) cause flaccid paralysis (muscles are relaxed and cannot contract) |
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Term
If the person was suffering from severe hyperkalemia, you would expect
a.) the potassium ion concentration of the intersitial fluid to be less than normal
b.) the membrane potential of nerves and muscles to be more negative
c.) the skeletal muscles to be unresponsive and cardiac arrest to occur
d.) muscle weakness and increased strength of twitch contraction
e.) both a and d |
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Definition
| c.) the skeletal muscles to be unresponsive and cardiac arrest to occur |
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Term
Athletes usually go through a "warm-up" period before engaging in an event. The reason for this "warm up" period would be to take advantage of:
a.) incomplete tetanus
b.) complete tetanus
c.) treppe
d.) wave summation
e.) recruitment |
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Definition
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Term
Muscles that act as valves to open and close openings are:
a.) parallel
b.) convergent
c.) pinnate
d.) bipennate
e.) circular |
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Definition
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