Marie is in the emergency room with a severe anxiety attack. The ER doctor administers a dose of potassium to control her elevated heart rate. Why would potassium be a potential treatment for the cardiovascular effects of an anxiety attack?Multiple ChoiceElevated potassium ion concentration causes decreased heart rate and decreased force of contraction.Elevated potassium ion concentration causes decreased heart rate and increased force of contraction.Elevated potassium ion concentration reduces parasympathetic nervous system ouput which, in turn, decreases heart rate.Elevated potassium ion concentration reduces sympathetic nervous system ouput which, in turn, increases heart rate.

The MOST LIKELY effect of increasing the potassium conductance in a cardiac pacemaker cell would be

An increase in the concentration of plasma potassium causes increase in:a) release of reninb) secretion of aldosteronec) secretion of ADHd) release of natriuretic hormonee) production of angiotensin II

Explain what pathological changes cause Lydia's potassium to rise.

Which of these factors would cause an increase in heart rate?Multiple ChoiceIncreased parasympathetic stimulationA decrease in carbon dioxide in the bloodStimulation of baroreceptors in the aortaExcess potassium ionsA decrease in blood pH

Finally, Rebecca conducted an experiment in which she added a small amount of concentrated KCl solution to the extracellular medium, doubling the value of [K+]out. She investigated how this affected the electrophysiological properties of the neurone. Before increasing extracellular K+ concentration the neurone was silent, ie. did not fire action potentials. After increasing [K+]out by adding KCl to the extracellular medium she observed