PhysioEx3NeurophysioogyHWKQUestions Wolf
Exercise 3
Neurophysiology of Nerve Impulses
Activity 1
1. What happens to the resting membrane potential when extracellular K+ concentration is increased?
-The resting membrane potential will become more positive when K+ concentration is increased.
2. Explain why the resting membrane potential had the same value in the cell body and in the axon.
-The resting membrane potential has the same value in the cell body and the axon because the typical resting membrane potential is the same throughout the entire neuron.
3. Describe what would happen to the resting membrane potential if the sodium-potassium transport pump was blocked.
-If the potassium transport pump was blocked the leakage channels would still be open allowing Na+ to leak in while K+ would be leaking out based on diffusion.
4. Explain why increasing extracellular K+ reduces the net diffusion of K+ out of the neuron through the K+ leak channels.
-Increasing extracellular K+ reduces the net diffusion through the leak channels because if there are an increased amount of K+ ions outside of the cell, the amount coming from the leak channels needs to decrease so it can be balanced.
5. Explain why a change in extracellular Na+ did not alter the membrane potential in the resting neuron.
-A change in Na+ did not alter the membrane potential in the resting neuron because there are less leakage sodium channels than leakage potassium channels, and more of the potassium channels are open.
Activity 2
1. Define graded potential. How does your data show that stimulation of the olfactory receptor is graded?
Graded potential are local changes in membrane potential or short duration. These can be depolarizing which are less negative or hyperpolarizing which are more negative. The data that I collected shows that the olfactory receptor is graded because the resting potential, peak value response, and the amplitude of response are all very close in number.
2. In your experiment which receptors
Neurophysiology of Nerve Impulses
Activity 1
1. What happens to the resting membrane potential when extracellular K+ concentration is increased?
-The resting membrane potential will become more positive when K+ concentration is increased.
2. Explain why the resting membrane potential had the same value in the cell body and in the axon.
-The resting membrane potential has the same value in the cell body and the axon because the typical resting membrane potential is the same throughout the entire neuron.
3. Describe what would happen to the resting membrane potential if the sodium-potassium transport pump was blocked.
-If the potassium transport pump was blocked the leakage channels would still be open allowing Na+ to leak in while K+ would be leaking out based on diffusion.
4. Explain why increasing extracellular K+ reduces the net diffusion of K+ out of the neuron through the K+ leak channels.
-Increasing extracellular K+ reduces the net diffusion through the leak channels because if there are an increased amount of K+ ions outside of the cell, the amount coming from the leak channels needs to decrease so it can be balanced.
5. Explain why a change in extracellular Na+ did not alter the membrane potential in the resting neuron.
-A change in Na+ did not alter the membrane potential in the resting neuron because there are less leakage sodium channels than leakage potassium channels, and more of the potassium channels are open.
Activity 2
1. Define graded potential. How does your data show that stimulation of the olfactory receptor is graded?
Graded potential are local changes in membrane potential or short duration. These can be depolarizing which are less negative or hyperpolarizing which are more negative. The data that I collected shows that the olfactory receptor is graded because the resting potential, peak value response, and the amplitude of response are all very close in number.
2. In your experiment which receptors