12 Questions
What is the initial level of membrane potential before the start of an action potential?
Resting potential
During which phase of an action potential does the membrane potential first increase to reach a threshold level?
Depolarisation
What is the term used to describe the decrease in membrane potential after it reaches its peak during an action potential?
Repolarisation
Which ions move into the cell through voltage-gated channels during an action potential?
Na+ (Sodium)
What gates do Na+ ions pass through within the Na+ channel during their movement from the extracellular fluid to the cytosol?
Activation gate and inactivation gate
At what point during an action potential does the membrane potential go below the resting membrane potential?
Hyperpolarisation
What happens when the membrane potential reaches the threshold potential?
Activation gates in all Na+ channels open very rapidly.
What occurs when the membrane potential falls back to the threshold potential during the hyperpolarisation phase?
Na+ channel activation gates close again.
What is the state of the inactivation gate in the Na+ channel at resting membrane potential?
Open
When does the K+ channel's activation gate open during the depolarisation phase?
Slowly
When does the Na+ channel inactivation gate open during the repolarisation phase?
When the membrane potential begins to drop
What happens with the K+ channel activation gate just after peak membrane potential has been achieved?
It closes
Learn about the physiological process of action potentials, from the resting potential to depolarization and repolarization. Explore how membrane potential changes during this rapid increase and decrease.
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