Immediately after an action potential has peaked, which of the following channels will open?

WHat are ligand-gated ion channels?

QUESTION 2 What area represents the axon hillock? H B C NEURON K NEURON L D A F G LABEL C LABEL G LABEL H LABEL B

85

After the depolarisation phase of an action potential, the resting potential is restored by ______.   Question 15 options:   A)  the opening of voltage-gated potassium channels and the closing or inactivation of sodium channels.   B)  the opening of more voltage-gated sodium channels.   C)  a decrease in the membrane's permeability to potassium and chloride ions following closing of the chloride-potassium pump.   D)  a brief inhibition of the sodium-potassium pump.

A neuron is moving from a voltage of -60 mV to -40 mV. This neuron is .... A) hyperpolarizing B) is making a contraction. C) repolarizing D)depolarizing

Question 4 Place the following events in order of their occurrence. 1. membrane repolarizes 2. K+ voltage gated channels open 3. Na+ voltage gated channels close 4. threshold is reached 5. membrane depolarizes 6. Na+/K+ pump reestablishes resting potential 7. Na+ moves through non-gated channels 8. Na+ voltage gated channels open 9. hyperpolarization then closure of K+ gates 10. membrane depolarizes to peak O 7.5.4.8.10.3.2.1.9.6 O 5.9.4.3.10.1.2.8.6.7. O 3.7.9.5.10.6.4.2.1.8 O9.6.8.10.2.5.7.1.3.4.9. « Previous

A sodium channel in a nerve membrane a)Inactivation gate closes when the membrane reaches ~+30 mV. b)Opens and closes quickly. c)Activation gate opens when the membrane reaches threshold voltage. d)'Resets' when the membrane reaches resting potential .

13) Draw a graph representing the changes in membrane potential across the axonal membrane before, during, and after an action potential. On your graph, use a highlighter to clearly indicate for which portions of your graph the letter corresponding to each cellular event listed below belongs. List of cellular events: A) All K* channels open B) All Na* channels close C) The Na*/K* ATPase cotransporter transports Na* and K* across the membrane. D) All Na* channels open E) The threshold value of membrane potential is attained. F) All K* channels close G) Some Na* channels open Your graph:

Depolarization phase      --Click to select--   Chemically-gated potassium channels   Chemically-gated sodium channels   Voltage-gated potassium channels   Voltage-gated sodium channels     Repolarization phase      --Click to select--   Voltage-gated potassium channels   Voltage-gated sodium channels   Chemically-gated sodium channels   Chemically-gated potassium channels     Hyperpolarization phase      --Click to select--   Voltage-gated sodium channels   Chemically-gated potassium channels   Voltage-gated potassium channels   Chemically-gated sodium channels