explain how each of the choices selected above RMP K leack channel and sodium and potassium pump and concentration gradient and membrane permeablity why RMP is -70

 

the factors that contribute to the resting membrane potential (RMP) of a neuron and why it is typically around -70 mV.

Leak Channels:

Neurons have leak channels (also known as non-gated channels) that allow ions (such as potassium and sodium) to passively move across the cell membrane.

These channels are always open and contribute to the resting membrane potential.

The most important leak channel for RMP is the potassium leak channel (K⁺ channel). It allows potassium ions (K⁺) to move out of the cell, making the inside of the cell more negative.

Sodium-Potassium Pump (Na⁺/K⁺ Pump):

The sodium-potassium pump actively transports sodium ions (Na⁺) out of the cell and potassium ions (K⁺) into the cell.

For every three sodium ions pumped out, two potassium ions are pumped in.

This pump helps maintain the concentration gradients of sodium and potassium across the cell membrane, which is crucial for RMP.

Concentration Gradient:

The concentration gradient refers to the difference in ion concentrations between the inside and outside of the cell.

At rest, there is a higher concentration of potassium ions (K⁺) inside the cell and a higher concentration of sodium ions (Na⁺) outside the cell.

The potassium leak channel allows potassium ions to move out of the cell along their concentration gradient, contributing to the negative RMP.

Membrane Permeability:

The permeability of the cell membrane to different ions affects RMP.

The cell membrane is more permeable to potassium ions (K⁺) due to the abundance of potassium leak channels.

Sodium ions (Na⁺) have fewer leak channels, so their contribution to RMP is smaller.

Now, let’s tie it all together:

The potassium leak channel allows potassium ions to leak out of the cell, making the inside more negative.

The sodium-potassium pump maintains the concentration gradients by actively pumping sodium out and potassium in.

The net effect of these processes results in an RMP of approximately -70 mV.

Remember that RMP can vary slightly depending on the specific type of neuron and its environment, but -70 mV is a common value. 

If you have any more questions or need further clarification, feel free to ask! 😊