In part one of the IBDP BIology Blog post, we will learn the resting and action potential of the nerve impulses, and how the impulse is passed along a neuron, let's get started!
How a nerve impulse passes along a non-myelinated neuron
Below: ion pump in a plasma membrane.
Resting Potential
At rest there is a potential difference between the outside of the membrane of an axon and the inside. The usual value used is - 70mV.
Outside is positively charged.
Inside is negatively charged.
Concentration of Na+(Sodium) is higher on the outside.
Concentration of K+(Potassium) is higher on the inside.
Both are positive so there is no potential difference. The distribution of Cl- makes the resting potential. This is maintained by the properties of the selectively permeable membrane.
Action potential
Information travels down a neuron as an action potential.
AP is generated by a stimulus of a receptor or from an AP from another connecting neuron.
Although the potential difference is back to original values, the sodium and potassium ions are in the wrong place.
The sodium/potassium pump will return them to original positions via active transport.
Action potentional is the time of depolarization (1msec).
That is all for Part one!
References:
- https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.researchgate.net%2Ffigure%2FSketch-of-the-structure-of-the-cell-membrane-showing-the-ion-gradient-ion-channel-and_fig4_318361386&psig=AOvVaw3FOE-68Jo3qhHVjpwU7QUr&ust=1627052260444000&source=images&cd=vfe&ved=0CAsQjRxqFwoTCJC1oqX49vECFQAAAAAdAAAAABAD
Drafted by Venetia (Biology)