Summary
About -70 mV across a neuron membrane maintained by ion pumps and leak channels.
In depth
The Na+/K+ pump and K+ leak channels create a potential near -70 mV; K+ diffuses out more than Na+ diffuses in, leaving the interior negative. The Nernst equation predicts equilibrium potentials per ion.
The potential results from selective permeability to K+. The Goldman equation predicts it from multiple ions. Pumps maintain gradients over time.
Key idea: the cell interior is negative relative to outside.
The resting potential is mainly due to selective K+ permeability through leak channels, and the Nernst equation gives the equilibrium potential of each ion: K+ about minus 90 mV, Na+ about plus 60 mV. The Goldman equation combines ions weighted by permeability. At rest, permeability to K+ is about 50 to 100 times that of Na+, so the potential is near EK. Large anions (proteins) trapped inside add to negativity. The pump is electrogenic and keeps gradients over time, but contributes only a few mV directly.
Changes in extracellular K+ shift the potential: high potassium (hyperkalaemia) depolarises cells and can stop the heart; potassium chloride is used in lethal injection. Local anaesthetics block sodium channels. Resting potential varies: muscle about minus 90, neurons minus 70, glia minus 80 mV.
Key idea: neurons are like batteries, with ion gradients storing energy for signalling.
Frequently asked questions
What is Resting Membrane Potential?
About -70 mV across a neuron membrane maintained by ion pumps and leak channels.
Which area of biology covers Resting Membrane Potential, and how advanced is it?
Resting Membrane Potential is one of the 54 topics in Neuroscience. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Depolarisation and Repolarisation, Action Potential, Synaptic Transmission.
Can you give an example of Resting Membrane Potential?
Raising extracellular K+ depolarises neurons, which is why high potassium is dangerous for the heart.
What should I learn before Resting Membrane Potential?
Work through the Beginner topics in Neuroscience first, such as Nervous System, Neuron, Central and Peripheral Nervous Systems, then return to Resting Membrane Potential. Intermediate topics assume the Beginner vocabulary.
What topics are related to Resting Membrane Potential?
The closest topics to Resting Membrane Potential are Depolarisation and Repolarisation, Action Potential, Synaptic Transmission, Voltage-Gated Ion Channels. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Resting Membrane Potential?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Resting Membrane Potential. To practise the whole of Neuroscience, use the Neuroscience quiz.
How is Resting Membrane Potential different from Depolarisation and Repolarisation?
Resting Membrane Potential: About -70 mV across a neuron membrane maintained by ion pumps and leak channels. Depolarisation and Repolarisation: Sodium channels open and the cell becomes positive, then potassium channels open to restore the negative interior. Read both side by side and note what each one explains.
How should I study Resting Membrane Potential step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Depolarisation and Repolarisation and explain the difference aloud. Finally, take the Neuroscience quiz and come back to this page for any question you miss.