Biology 241 - Accelerated General Human Physiology » Summer 2021 » Lab Q11

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Question #1
During the skeletal muscle simulation, a low-voltage electrical stimulus (0 or 0.1 volts) produced no response on the screen because:
A.   the stimulus must produce many action potentials in the muscle fibers to evoke a contraction.
B.   the stimulus did not stimulate any muscle fibers to threshold.
C.   the evoked action potential was too small to produce a visible contraction.
D.   the muscle contraction was too small to register.
Question #2
The latency period is the time:
A.   period between stimulation and the shortening of the skeletal muscle.
B.   period when the level of calcium in the cytoplasm is greater than at rest.
C.   when cross-bridge cycling is taking place and the muscle is shortening.
D.   taken for a skeletal muscle to contract and relax.
Question #3
When the muscle had weights attached and trying to contract, what was happening during the latency period:
A.   the muscle was contracting isometrically.
B.   there was no tension in the tendon.
C.   the muscle was not contracting.
D.   the muscle was lifting the weight.
Question #4
According to the Length-Tension relationship, maximum tension is produced in a skeletal muscle fiber when it is:
A.   tension is constant at all muscle lengths
B.   longer than resting length
C.   shorter than resting length
D.   at or near resting length
Question #5
During incomplete tetanus, the amount of tension increases above that seen with a single twitch because:
A.   sarcoplasmic calcium levels drop.
B.   the muscle twitches fuse into a single, maximum contraction.
C.   there is accumulation of calcium in the sarcoplasm.
D.   maximum tension is achieved.
Question #6
Why would the rate of muscle relaxation be slower after tetanus than after a single twitch?
A.   There is maximum amount of overlap between the thick and thin myofilaments.
B.   The contraction was larger, so the rate of relaxation would be slower.
C.   Cross-bridges are formed during relaxation.
D.   It takes time for the large amount of calcium in the sarcoplasm to be taken up by the sarcoplasmic reticulum.
Question #7
Match the terms with its definition. muscle twitch
A.   muscle response from a single action potential
B.   declining muscle force during a sustained contraction
Question #8
Match the terms with its definition. tetanus
A.   maximum muscle force
B.   muscle response from a single action potential
Question #9
Match the terms with its definition. latent period
A.   time between action potential stimulus and muscle activation
B.   maximum muscle force
Question #10
Match the terms with its definition. motor unit
A.   time between action potential stimulus and muscle activation
B.   a single motor nueron and all the muscle fibers it innervates
Question #11
Match the terms with its definition. recruitment
A.   a single motor nueron and all the muscle fibers it innervates
B.   adding more muscle units to complete a task
Question #12
Match the terms with its definition. fatigue
A.   adding more muscle units to complete a task
B.   declining muscle force during a sustained contraction
Question #13
The electromyogram (EMG) records:
A.   electrical activity from the lower motor neurons.
B.   tension in the contracting muscle.
C.   electrical activity from the contracting muscle fibers.
D.   the movement of the contracting muscle.
Question #14
If the peak-to-peak amplitude of the EMG is an indication of the number of muscle fibers contracting, an increase in dynamometer pressure was produced by:
A.   more muscle fibers contracting.
B.   fewer muscle fibers contracting.
C.   the same number of muscle fibers contracting.

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