PNB 2274 EXAM QUESTIONS AND
ANSWERS ALL CORRECT
What is the cause of the blip (?) in the [Na+] current trace? (Circled in purple in the
image above) - Answer- The blip is from ligand-gated channels closing, and it takes a
moment for the voltage-gated ones to open.
Check Answer
Review the data generated in your 3D graph. What is the maximum temperature (C) to
generate an action potential under the default cellular ion settings? What trends in the
action potential do you notice as the temperature begins to decrease? - Answer- 22
degrees C was the maximum temperature under which an action potential could form.
As the temperature decreased, the action potentials got wider and took longer to be
carried out. At higher temperatures, the action potential was sharp.
When placing recording electrodes 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) Ensure
that the electrodes are in good contact with the skin.
During your recording, you see a flat line being recorded. What should you do?
A) Complete the experiment first and then adjust the scale.
B) Adjust the scale immediately.
C) Complete the experiment. It is not important for the experiment.
D) Report it to your lab instructor. - Answer- B) Adjust the scale immediately.
Which of the following is an acceptable scientific hypothesis?
A) Genetically modified tomatoes contain a lot of fructose.
B) Genetically modified tomatoes are very expensive.
C) Customers should buy more genetically modified tomatoes, because they are
healthier.
D) Genetically modified tomatoes contain more fructose than conventional tomatoes. -
Answer- D) Genetically modified tomatoes contain more fructose than conventional
tomatoes.
Referring to your hypothesis in Exercise 1, your simulation results in Exercise 2, and
your membrane drawing in Exercise 3, predict the mechanism of action of tetrodotoxin
, (TTX) on a neuron. - Answer- TTX must block the voltage-gated sodium channels,
preventing an action potential from firing.
Which structure separates the right and left cerebral hemispheres?
A) Central sulcus
B) Lateral sulcus
C) Longitudinal fissure
D) Transverse fissure - Answer- C) Longitudinal fissure
Which structure is found on the frontal lobe?
A) Central sulcus
B) Lateral sulcus
C) Precentral gyrus
D) Postcentral gyrus - Answer- C) Precentral gyrus
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) Twitches in all the fibers
of several motor units.
One motor unit can respond with multiple twitches per stimulus.
A) True
B) False - Answer- B) False
What is the optimal sarcomere length for maximal force generation in muscle?
A) Fully stretched
B) Intermediate length
C) Completely contracted - Answer- B) Intermediate length
A single motor neuron innervates one muscle fiber.
A) True
B) False - Answer- B) False
Which of the following is NOT a mechanism of fatigue?
A) Conduction failure
B) Lactic acid buildup
C) Inhibition of cross-bridge cycling
D) Neurotransmitter breakdown - Answer- D) Neurotransmitter breakdown
In light of the "all or none" law of muscle contraction, how can you explain the graded
response? - Answer- Graded responses are the result of a change in the number of
motor units recruited. You can recruit a larger or smaller motor unit, or combine multiple
motor units to generate more force.
ANSWERS ALL CORRECT
What is the cause of the blip (?) in the [Na+] current trace? (Circled in purple in the
image above) - Answer- The blip is from ligand-gated channels closing, and it takes a
moment for the voltage-gated ones to open.
Check Answer
Review the data generated in your 3D graph. What is the maximum temperature (C) to
generate an action potential under the default cellular ion settings? What trends in the
action potential do you notice as the temperature begins to decrease? - Answer- 22
degrees C was the maximum temperature under which an action potential could form.
As the temperature decreased, the action potentials got wider and took longer to be
carried out. At higher temperatures, the action potential was sharp.
When placing recording electrodes 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) Ensure
that the electrodes are in good contact with the skin.
During your recording, you see a flat line being recorded. What should you do?
A) Complete the experiment first and then adjust the scale.
B) Adjust the scale immediately.
C) Complete the experiment. It is not important for the experiment.
D) Report it to your lab instructor. - Answer- B) Adjust the scale immediately.
Which of the following is an acceptable scientific hypothesis?
A) Genetically modified tomatoes contain a lot of fructose.
B) Genetically modified tomatoes are very expensive.
C) Customers should buy more genetically modified tomatoes, because they are
healthier.
D) Genetically modified tomatoes contain more fructose than conventional tomatoes. -
Answer- D) Genetically modified tomatoes contain more fructose than conventional
tomatoes.
Referring to your hypothesis in Exercise 1, your simulation results in Exercise 2, and
your membrane drawing in Exercise 3, predict the mechanism of action of tetrodotoxin
, (TTX) on a neuron. - Answer- TTX must block the voltage-gated sodium channels,
preventing an action potential from firing.
Which structure separates the right and left cerebral hemispheres?
A) Central sulcus
B) Lateral sulcus
C) Longitudinal fissure
D) Transverse fissure - Answer- C) Longitudinal fissure
Which structure is found on the frontal lobe?
A) Central sulcus
B) Lateral sulcus
C) Precentral gyrus
D) Postcentral gyrus - Answer- C) Precentral gyrus
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) Twitches in all the fibers
of several motor units.
One motor unit can respond with multiple twitches per stimulus.
A) True
B) False - Answer- B) False
What is the optimal sarcomere length for maximal force generation in muscle?
A) Fully stretched
B) Intermediate length
C) Completely contracted - Answer- B) Intermediate length
A single motor neuron innervates one muscle fiber.
A) True
B) False - Answer- B) False
Which of the following is NOT a mechanism of fatigue?
A) Conduction failure
B) Lactic acid buildup
C) Inhibition of cross-bridge cycling
D) Neurotransmitter breakdown - Answer- D) Neurotransmitter breakdown
In light of the "all or none" law of muscle contraction, how can you explain the graded
response? - Answer- Graded responses are the result of a change in the number of
motor units recruited. You can recruit a larger or smaller motor unit, or combine multiple
motor units to generate more force.
