N5315 M10 Advanced Pathophysiology Update A+ Review

N5315 Module 1 and Module 2 Steps of action potentiial ANSWER: Process by which excitable cells transmit information to one another Occurs mostly in nerve and muscle cells Action potential altered by calcium imbalance ANSWER: Hyopcalcemia: increases cell permeability to sodium - progressive depolarization — RMP and threshold potential to be closer — easier to activate action potential - cells are more excitable - tetany, hyperflexia, circumoral pareshesias, seizure, dysrhythmias Hypercalcemia: decreases cell permeability to sodium - distance between the RMP and the threshold potential - widening QRS, cardiac standstill if RMP = threshold potential, paralysis/parestheia Action potential altered by potassium imbalances ANSWER: Hypokalemia:ECF K is depleted and ICF K diffuses out of the cell easily - cell to hyperpolarize (more negative). Less likely to depolarize and transmit impulses - decrease neuromuscular excitability, weakness, parenthesias, cardiac dysrhythmias Hyperkalemia: ECF K increases without ICF K changes — RMP becomes more positive (hypopolarized) - cells are more excitable and conduct more impulses - peak T wave, elevated