Membrane potential

Definition

Membrane potential is the voltage difference across a cell membrane due to the distribution of ions. It is crucial for the conduction of electrical impulses in cardiac cells.

5 Must Know Facts For Your Next Test

1. Normal resting membrane potential in cardiac cells is around -90 mV.
2. Action potentials occur when membrane potential rapidly rises and falls, which is essential for heart contractions.
3. Ion channels such as sodium, potassium, and calcium channels play a key role in establishing membrane potential.
4. Depolarization occurs when the membrane potential becomes less negative, leading to muscle contraction.
5. Repolarization restores the resting membrane potential after depolarization, ensuring readiness for the next impulse.

Review Questions

• What is the typical resting membrane potential in cardiac cells?
• Which ion channels are involved in establishing and changing membrane potential?
• Explain the processes of depolarization and repolarization in cardiac cells.

Related terms

Action Potential: Rapid rise and fall in membrane potential that transmits electrical impulses.

Depolarization: The process by which the membrane potential becomes less negative, initiating an action potential.

Repolarization: The process of restoring the resting membrane potential after depolarization.