PNB 2274 Practical II Practice
Questions with All Correct Answers
2026 Updated.
A motor unit includes:
a. Multiple muscle fibers innervated by multiple motor neurons.
b. One muscle fiber innervated by multiple motor neurons.
c. Multiple muscle fibers innervated by one motor neuron
d. One muscle fiber innervated by one motor neuron - Answer C
Definition of a motor unit
What was the objective of the electromyography lab? - Answer To explore the electrical
activity of skeletal muscles.
The EMG is a recorder of:
a. The action potential of the motor nerves supplying the muscle fibers.
b. The contraction forces of the innervated muscle fibers.
c. The action potentials of the innervated muscle fibers. - Answer C
Define agonist and antagonist. - Answer Agonist: Produces an action
Antagonist: Opposes an action
A transducer is a device that converts a signal to an analog signal.
a. True
b. False - Answer A
The PowerLab hardware is NOT designed to:
a. Convert analog signal to a digital signal.
b. Amplify a signal
c. Filter a signal
d. Display a signal - Answer D
What is co-contraction?
a. The simultaneous contraction of both the agonist and the antagonist muscles.
b. The simultaneous contraction of an agonist muscle and inhibition of an antagonist muscle.
, c. The inhibition of both the agonist muscle and the antagonist muscle.
d. None of the above - Answer A
What is reciprocal activation?
a. The simultaneous contraction of both the agonist and the antagonist muscles.
b. The simultaneous contraction of an agonist muscle and inhibition of an antagonist muscle.
c. The inhibition of both the agonist muscle and the antagonist muscle.
d. None of the above - Answer B
When placing recording electrodes for EMG recordings on the biceps and triceps:
a. Place electrodes near hairy areas
b. Consider placing it on the surface of tendons and joints
c. Ensure that the electrodes are in good contact with the skin
d. Place the ground electrode close to the recording electrode - Answer C
During a recording of EMG there is a flat line being recorded. What should you do?
a. Complete the trial and then adjust the scale.
b. Adjust the scale immediately.
c. Complete the experiment and do not adjust the scale.
d. Report it to your lab instructor. - Answer B
What was the objective in measuring the activity of the isolated frog gastrocnemius? - Answer
To display the relationship between intensity of muscle stimulation and contractile force. Also to
display the effects of muscle stretch, summation, tetanus, and fatigue.
Recruitment refers to:
a. Multiple twitches in one fiber of one motor unit.
b. Twitches in all the fibers of several motor units.
c. One twitch in multiple fibers of one motor unit. - Answer B
What is the maximum excitation voltage? - Answer The highest voltage at which has the
largest response.
Supramaximal Pulse Height - Answer Supramaximal Pulse Height = 1.5*Maximum Excitation
Voltage
Questions with All Correct Answers
2026 Updated.
A motor unit includes:
a. Multiple muscle fibers innervated by multiple motor neurons.
b. One muscle fiber innervated by multiple motor neurons.
c. Multiple muscle fibers innervated by one motor neuron
d. One muscle fiber innervated by one motor neuron - Answer C
Definition of a motor unit
What was the objective of the electromyography lab? - Answer To explore the electrical
activity of skeletal muscles.
The EMG is a recorder of:
a. The action potential of the motor nerves supplying the muscle fibers.
b. The contraction forces of the innervated muscle fibers.
c. The action potentials of the innervated muscle fibers. - Answer C
Define agonist and antagonist. - Answer Agonist: Produces an action
Antagonist: Opposes an action
A transducer is a device that converts a signal to an analog signal.
a. True
b. False - Answer A
The PowerLab hardware is NOT designed to:
a. Convert analog signal to a digital signal.
b. Amplify a signal
c. Filter a signal
d. Display a signal - Answer D
What is co-contraction?
a. The simultaneous contraction of both the agonist and the antagonist muscles.
b. The simultaneous contraction of an agonist muscle and inhibition of an antagonist muscle.
, c. The inhibition of both the agonist muscle and the antagonist muscle.
d. None of the above - Answer A
What is reciprocal activation?
a. The simultaneous contraction of both the agonist and the antagonist muscles.
b. The simultaneous contraction of an agonist muscle and inhibition of an antagonist muscle.
c. The inhibition of both the agonist muscle and the antagonist muscle.
d. None of the above - Answer B
When placing recording electrodes for EMG recordings on the biceps and triceps:
a. Place electrodes near hairy areas
b. Consider placing it on the surface of tendons and joints
c. Ensure that the electrodes are in good contact with the skin
d. Place the ground electrode close to the recording electrode - Answer C
During a recording of EMG there is a flat line being recorded. What should you do?
a. Complete the trial and then adjust the scale.
b. Adjust the scale immediately.
c. Complete the experiment and do not adjust the scale.
d. Report it to your lab instructor. - Answer B
What was the objective in measuring the activity of the isolated frog gastrocnemius? - Answer
To display the relationship between intensity of muscle stimulation and contractile force. Also to
display the effects of muscle stretch, summation, tetanus, and fatigue.
Recruitment refers to:
a. Multiple twitches in one fiber of one motor unit.
b. Twitches in all the fibers of several motor units.
c. One twitch in multiple fibers of one motor unit. - Answer B
What is the maximum excitation voltage? - Answer The highest voltage at which has the
largest response.
Supramaximal Pulse Height - Answer Supramaximal Pulse Height = 1.5*Maximum Excitation
Voltage
