How does increasing extracellular K+ reduce the net diffusion of K+ out of the neuron through the K+ leak channels?
Increasing extracellular K+ reduces the steepness of the concentration gradient so less K+ diffuses out of the neuron
How does increasing extracellular K+ cause the membrane potential to change to a less negative value?
Increasing extracellular K+ causes the membrane potential to become less negative because less K+ diffused out. The more K+ stays in, the more positive/less negative.
Explain why a change in extracellular Na+ did not alter the membrane potential in the resting neuron.
1. There are less leaking Na+ channels than leaking K+ channels
2. More K+ channels are open
Discuss the relative permeability of the membrane to Na+ and K+ in a resting neuron
A resting neuron is 4-5 times more permeable to K+ because of the number of increased leak channels.
Discuss how a change in Na+ or K+ conductance would affect the resting membrane potential.
A change in the K+ conductance would have a greater affect on the resting membrane potential than would a change in Na+