Question
Please answer the following questions for numbers 27,28 and 29. If you are not sure please write it next to the problem number. I am a little confused on these, I will rate good!
Q 27-28. Refer to the figure below to answer questions 27-28: -65 -100 -100 Capacitive transient Capacitive transient Inward ionic Outward ionic current Time Time 27. The treatment difference between the membranes shown in the two graphs is that the membrane on the left is , while the membrane on the right is being a. a control depolarization; depolarized while soaking in Na -free seawater b. a control depolarization; depolarized while soaking in TEA c. a control depolarization; depolarized while soaking in a solution with the same concentration of Na* as the concentration inside the cell d. being hyperpolarized; depolarized e. being depolarized; hyperpolarized 28. How would the trace on the right look if the neuron was soaking in the K' channel blocker TEA? a. The inward ionic current would disappear. b. The outward ionic current would disappear. c. The trace would look exactly like the trace in the left panel. d. The inward ionic current would be amplified. e. The outward ionic current would be amplified. 29. Myelination by Schwann cells increases the velocity of action potential propagation by... a. increasing axon resistance and decreasing axon capacitance, allowing the action potential to "jump" over the myelinated area. b. decreasing the resistance and increasing the capacitance, allowing the action potential to "jump" over the myelinated area. c. increasing the diameter of the neuron. d. increasing the number of voltage-gated sodium channels. e. increasing the resistance and increasing the capacitance, allowing the action potential to "jump" over the myelinated area.
Explanation / Answer
Answer
Membrane action potential: There are four phase of action potential 1-resting phase 2- Depolarization 3- repolarization and Hyperolarization. In resting phase the movement of ion stop in their native form which has develop some potential of ~-70mV .Then after the stimulus of minimum threshold depolarised the membrane sodium channel open and movement of Na+ outward to the cell it will increase the potential to more positive the again Depolarization decrease the action potential to the negative value and at last at hyperpolarized state the action potential is more negative to the resting potential.
So according to the information in question 27 the left graph shows more negative value then resting potential then the membrane is hyperpolarized and the graph in right side the potential is more positive than resting then the membrane is depolarised.
Probable answer is (d) for question 27