What is the Difference Between Depolarization and Repolarization?
🆚 Go to Comparative Table 🆚Depolarization and repolarization are processes that occur during the transmission of nerve impulses in cells, such as neurons and heart cells. They involve the changes in membrane potential, which are regulated by the opening and closing of ion channels. Here are the main differences between depolarization and repolarization:
- Depolarization:
- The movement of a cell's membrane potential to a more positive value.
- Caused by the opening of voltage-gated sodium channels, allowing positively charged sodium ions to enter the cell.
- Increases the membrane potential, making the inside of the cell less negative.
- Facilitates the firing of an action potential.
- Repolarization:
- The change in membrane potential from a positive to a negative value.
- Caused by the closing of sodium ion channels and the opening of potassium ion channels, allowing positively charged potassium ions to exit the cell.
- Decreases the membrane potential and restores the resting membrane potential.
- Prevents the firing of an action potential.
In the context of the heart, depolarization of heart cells leads to contraction, while repolarization leads to relaxation. The process of depolarization and repolarization creates the electrocardiogram (ECG) reading, which is caused by the electrical conduction system of the heart.
On this pageWhat is the Difference Between Depolarization and Repolarization? Comparative Table: Depolarization vs Repolarization
Comparative Table: Depolarization vs Repolarization
Here is a table comparing the differences between depolarization and repolarization:
Feature | Depolarization | Repolarization |
---|---|---|
Definition | Depolarization is the process that causes an action potential due to the influx of Na+ ions into the neuron. | Repolarization is the change in membrane potential that returns to its negative value, preventing the firing of an action potential. |
Membrane Potential | Increases the membrane potential. | Decreases the membrane potential and restores the resting membrane potential. |
Ion Channels Involved | Caused by the opening of voltage-gated sodium channels. | Caused by the closing of sodium ion channels and the opening of potassium ion channels. |
Effect on Action Potential | Facilitates the firing of an action potential. | Prevents the firing of an action potential. |
Polarity Change | Causes the membrane potential to become more positive. | Causes the membrane potential to become more negative. |
Read more:
- Depolarization vs Hyperpolarization
- Resting Potential vs Action Potential
- Magnetization vs Demagnetization
- EPSP vs IPSP
- Phosphorylation vs Dephosphorylation
- Anodic vs Cathodic Polarization
- Concentration Polarization vs Kinetic Polarization
- Excitation vs Ionization Potential
- Polarizable vs Non Polarizable Electrode
- Protonation vs Ionization
- Potential Difference vs Voltage
- Graded Potential vs Action Potential
- Ionization vs Dissociation
- Electropositive vs Electronegative
- EMF vs Potential Difference
- Depolarizing vs Nondepolarizing Neuromuscular Blockers
- Polar vs Dipolar Molecules
- Polarizability vs Dipole Moment
- Vasoconstriction vs Vasodilation