Question

QUESTION 8 he membrane potential becomes more negative than the resting potential during the after-hyperpolarization phase of the action potential (AHP) because Ligand-galed Nat channels are inactivated and cannot be opened Voltage-gated K channels become inactivated The K equilibrium potential is below the resting membrane potential All ofthe above. None of the above QUESTION 9 When an action potential reaches the axon terminal, release of neurotransmitter is triggered by... a. movement of sodium ions into the axon terminal b. movement of calcium ions into the axon terminal movement of sodium ions into the neuron at the nodes of Ranvier d. movement of calcium ions into the neuron at the nodes of Ranvier . either a or b will trigger neurotransmitter release. QUESTION 10 Which of the following is true for chemical synapses? they allow for the flow of electrical current in either direction they can pass positive or negative current action potentials are required for transmission of information they are almost instantaneous e. all of the above are true

Answer 1

Question 8

The membrane potential becomes more negative than the resting potential during the after-hyperpolarization phase of the action potential because :

A large number of voltage-gated K+ channel opening during the repolarization phase quickly makes the membrane potential more negative as positively charged K+ ions leave the cell.K+ ions continues to leave through open channels as the membrane potential passes becomes more negative than the resting potential. This hyperpolarization phase of the action potential is, therefore, due to K+ ions diffusing through voltage-gated K+ channels. The membrane potential remains more negative than the resting potential until voltage-gated K+ channels close. his period of hyperpolarization is important in relieving voltage-gated Na+ channels from inactivation, readying them for another action potential.

So here the answer is option 'c' "all of the above"

Question 9

When an action potential reaches the axon terminal, the release of neurotransmitter is released by:

Here the answer is option 'b', that means the movement of calcium ions into the terminal.

Question 10

Which of the folwing is true for chemical synapses

Here the answer is option 'd 'that means all of the above are true