action potential Flashcards
1
Q
how is an action potential generated
A
by a change in membrane permeability.
a stimulus will cause an influx of positively charged soidum ions.
the potential difference rises to a less negative voltage.
some failed initiations of an action potential.
depolarisation until threshold is reached (-55mV) and voltage gated sodium ion channels open. sodium ions rapidly diffuse in. pot diff rises to 40mV inside of cell is now more positive than outside
2
Q
repolarisation
A
voltage gated potassium channels open and sodium channels close potassium ions quickly diffuse out restoring permeability and repolarising the membrane.
