How is the resting membrane potential established in a neurone?

The membrane of an axon consists of three main protein channels: the sodium/potassium pumps, voltage-gated sodium channels and voltage-gated potassium channels. These play a role in establishing the membrane potential. The sodium potassium pump, actively pumps 3 sodium ions (Na+) outside of the neurone and 2 K+ inside the cell. This causes a net difference across the axon, with the inside being slightly negative compared to the outside of the axon. The axon is also more permeable to K+ in comparision to Na+. Therefore, potassium will also leak out of the axon (contributing to the further negative state of the axon). The axon is more permeable to K+ as more K+ channels are open whilst most of the sodium channels are closed. Typical resting potential in a human: -70 mV.

UR

Related Biology A Level answers

All answers ▸

What are the different types of RNA used for during translation?


What is another model for enzyme activity?


Explain how FHS and oestrogen illustrate the principle of negative feedback during the menstrual cycle, and explain therefore why oestrogen may be used as a contraceptive.


Describe and explain the function alveoli