Case Study

1. Because of unequal charge of distribution.

2. Depolarization is when a membrane potential changes from a negative value towards zero. The membrane potential needs to be depolarized past the threshold so it can begin action potential. Hyperpolarization is when the membrane potential is moving away from normal resting potential and is further from zero. When the action potential’s been initiated, and the membrane potential has been repolarized and hyperpolarized it starts to become negative and can’t reach threshold.

3. A neuron is depolarized to threshold because of voltage -regulated sodium gates opening quickly and potassium gates opening slowly. Sodium enters the cell and makes a positive feedback loop and keeps the gates open. When it reaches zero, the potassium channels open completely and leaves the cell, and then the cell is repolarized.

4. Cole is saying that the anesthesia restrains the neurons because it stops the electrical activity of the brain; by blocking the synaptic transmission of neurotransmitters, and receptor channels in the neurons including ion channels. This interferes with the transfer of signals from neuron to neuron that actually constrains the neurons because there is no information being relayed.

5. Yes, because leak potassium channels help the cell maintain a stable resting potential and voltage-gated potassium channels are sensitive to voltage and can change the cell’s membrane potential.

6. Kevin’s neurons are less likely to produce action potentials because resting potential is bigger because of the potassium moving out of the cell, the concentration gradient opens the potassium leak channels. Now the membrane potential is closer to resting potential and further negative, so the neurons are not likely to go through action potential.

7. If extracellular concentration is high in potassium its gradient will move down into the cell. Because action potential is negative, this makes it easier for neurons to begin an action...