Help with all 17 Why are nerve cells so sensitive to extrace

Help with all!

17) Why are nerve cells so sensitive to extracellular K+ concentrations?

18) What ions are important when calculating the resting membrane?

19) What are the differences between the Nernst equation and the resting membrane equation?

20) Is a cell’s membrane ever at rest? If not, how can one remedy the resting membrane equation?

21) What is a resting potential… a graded potenial… what is an action potenial?

Solution

17). Neurons or nerve cells are very much sensitive to extracellular K+ concentration because, neurons are much more permeable to potassium ions (K+), therefore any change in the concentration of potassium ions affects the membrane potential.

Because the cell membrane has a high degree of permeablity to K+, increasing the extracellular concentration of K+ causes an equilibrium shift, which results in the influx of K+ into the cell. As the K+ concentration in the cell increases, the neuron interior becomes more positively charged relative to its exterior and membrane is said to be depolarized.