Major Difference Between Action Potential And Resting Potential

What Is Action Potential (AP)?

An action potential (AP) occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells referred to as excitable cells, which include neurons, muscle cells, endocrine cells, glomus cells and in some plant cells.

In neurons, action potentials play a central role in cell-to-cell communication by providing for the propagation of signals along the neuron’s axon toward synaptic boutons situated at the ends of an axon; these signals can then connect with other neurons at synapses or to motor cells or glands. In other types of cells, their main function is to activate intracellular processes.

What You Need To Know About Action Potential

• An action potential is a rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane with a characteristic pattern associated with passage of an impulse along the membrane of a muscle cell or nerve cell.
• The membrane is more permeable to sodium ions (Na+) than potassium ions (K+).
• The membrane is negatively charged outside and positively charged outside.
• An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls.
• Action potential has a value of approximately +40mV.
• Action potential is a rapid rise and fall when considering a particular location on the membrane.
• Voltage-gated sodium channels open up and voltage-gated potassium channels are closed at the action potential.
• Resting potential can either be followed by action potential or graded potential.
• Action potential allows the transmission of nerve impulses through the membrane.
• Action potentials occur in several types of animal cells referred to as excitable cells which include neurons, muscle cells, endocrine cells, glomus cells and in some plant cells.

What Is Resting Potential?

Resting potential is the imbalance of electrical charge that exists between the interior of electrically excitable neurons (nerve cells) and their surroundings. If the inside of a cell becomes more electronegative (i.e if the potential is made greater than the resting potential), the membrane or the cell is said to be hyperpolarized. If the inside of the cell becomes less negative (i.e the potential decreases below the resting potential), the process is called depolarization.

The resting membrane potential of cells varies depending on the cell type; the resting potential for neurons typically ranges between -50 and -75mV.  This value depends on the types of ion channels that are open and the concentrations of different ions in the intracellular and extracellular fluids.

What You Need To Know About Resting Potential

• Resting potential is the imbalance of electrical charge that exists between the interior of electrically excitable neurons (nerve cells) and their surroundings.
• The membrane is more permeable to potassium ions (K+) than sodium ions (Na+).
• The membrane is negatively charged from inside and positively charged from outside.
• The resting potential exists due to the differences in membrane permeabilities for potassium, sodium, calcium and chloride ions, which in turn result from functional activity of various ion channels, ion transporters and exchangers.
• In most neurons the resting potential has a value of approximately -70mV.
• The resting potential is relatively static.
• Both voltage-gated sodium and voltage-gated potassium ion channels are closed at the resting potential.
• Action potential is followed by hyperpolarization of the membrane. Hyperpolarization is a lowered membrane potential caused by the efflux of potassium ions and closing of the potassium channels.
• Resting potential does not allow the transmission of nerve impulses at rest.

Difference Between Action Potential And Resting Potential In Tabular Form