Specifics of an AP

Question 1

When threshold (-55) is reached…

Answer 1

Voltage gated Na+ ch. open at axon hillock

Question 2

Because of Na+ ch. opening, it is now depolarized to +3-

Answer 2

The opens the next set of voltage gated Na+ ch, Ap propogated along axon

Question 3

What is the turning point

Answer 3

When the Na+ ch. finally close, no more can enter. But V.Gated K+ ch open and REPOLARIZATION OCCURS.

Question 4

what happens when K+ gates are slow to close

Answer 4

Hyper polarization, cell is very negative.. But the pumps will eventually restore ion distribution

Question 5

what is absolute refractory period

Answer 5

When Na+ gate are still open so they cannot respond to another stimulus. Only channels further down can open ensuring that the AP goes toward the synaptic knob.

Question 6

What is relative refractory period

Answer 6

When the gates have reset by the cell is hyper polarized from to much K leaving. It’ll need an even stronger stimulus if they want it to open b/c its so negative rn.