Questions based on Physio ex 9.1 Neurophysiology of Nerve Impulses

1. Why does adding more potassium outside the neuron lead to a reduction in the diffusion of potassium from the neuron through potassium leak channels?  

2. Sensory neurons have a resting potential based on the efflux of potassium ions (as demonstrated in Activity 1). What passive channels are likely found in the membrane of the olfactory receptor, in the membrane of the Pacinian corpuscle, and in the membrane of the free nerve ending?

3. Identify which of the stimulus modalities induced the largest amplitude receptor potential in the Pacinian corpuscle and the olfactory. How well did the results compare with your predictions?

4. How does the threshold change during the relative refractory period?

5. Define what are A, B, and C fibers in regards to their ability to propagate action potentials.

6. What happened to the amount of neurotransmitter release when you switched from the control extracellular fluid to the extracellular fluid with no Ca2? How well did the results compare with your prediction?