BackHarry has a kidney condition that causes changes in his body's electrolyte levels (concentration of ions in the extracellular fluid). As a result, he is exhibiting tachycardia, an abnormally fast heart rate. Which ion is involved, and how does a change in its concentration cause Harry's symptoms?
Describe the events that must occur to generate an AP. Relate the sequence of changes in permeability to changes in the ion channels, and explain why the AP is an all-or-none phenomenon.
Albert, the patient in question 3, takes the drug lithium, which reduces the permeability of the neuronal axolemma to Na+ (that is, it allows fewer Na+ to enter the axon). Predict the effect this would normally have on his neuronal action potentials. Do you think this drug would be beneficial or harmful, considering his condition?
What is the polarized membrane state? How is it maintained? (Note the relative roles of both passive and active mechanisms.)
The anatomical region of a multipolar neuron where the AP is initiated is the
a. Soma
b. Dendrites
c. Axon's initial segment
d. Axon terminals
When an action potential is at its peak, the electrical gradient forces potassium ____________.