NSG 531 Advanced Pharmacology: Exam Questions With Correct Answers Latest Updated 2024/2025 Graded A+.

NSG 531 Advanced Pharmacology: Exam Questions With Correct Answers Latest Updated 2024/2025 Graded A+. what is the difference between cardiac myocyte action potential and that of the CNS or ANS? - ANSWER nerve cell action potential is very short cardiac action potential is much longer they are longer to have adequate filling time in order to get a good contraction for a reasonable bolus of blood the only way this can happen is if the action potential is longer this will also mean that the refractory period will be longer What are the 5 phases of the non-pacemaker action potential? - ANSWER 0 - depolarization 1 - partial repolarization 2 - plateau 3 - repolarization 4 - resting membrane potential what happens during phase 0 of the non-pacemaker action potential - ANSWER depolarization voltage gated sodium channels are opening up until we get past threshold what happens during phase 1 of the non-pacemaker action potential - ANSWER partial repolarization NSG 531 Rush Advanced Pharmacology: Exam 3 Questions With Correct Answers Latest Updated 2024/2025 / Graded A+. what happens during phase 2 of the non-pacemaker action potential - ANSWER plateau calcium channels open (L-type because they are long) potassium is still open potassium out and calcium in - they are opposing each other in voltage giving the plateau this is when the ventricles are filling what happens during phase 3 of the non-pacemaker action potential - ANSWER repolarization calcium channels are closed potassium channels are the only thing open taking their positive charge with them making the interior more negative what happens during phase 4 of the non-pacemaker action potential - ANSWER resting membrane potential where we are in between action potentials there is no net change in ovltage inside the cell When does contraction take place? - ANSWER begins towards the end of repolarization and ends at some point during repolarization refractory period - ANSWER during phase 0, 1, 2, and part of phase 3 the cell is refractory to the initiation of new action potentials many antiarrhythmic drugs increase the Refractory period which reduces myocyte excitability what are the benefits of the refractory period - ANSWER limits frequency of cardiac contractions allows for adequate filling time prevents sustained contractions how are pacemaker cells different from non-pacemaker cell - ANSWER no resting membrane potential - no point where it is flat there are very few sodium channels in pacemaker - sodium channels are not driving depolarization - calcium is only 3 phases comprised of cells within the SA node generate regular, spontaneous action potentials what are the phases of pacemaker action potential - ANSWER 0 - rapid depolarization 3 - repolarization 4 - slow depolarization what happens during phase 0 of the pacemaker action potential - ANSWER Rapid depolarization something is coming to open voltage gated calcium channels (L-type) calcium comes rushing in what happens during phase 3 of the pacemaker action potential - ANSWER repolarization potassium channels now open up, potassium rushes out, repolarizes what happens during phase 4 of the pacemaker action potential - ANSWER slow depolarization with potassium rushing out we are all the way down at -60 funny sodium channels open up until voltage reaches -50 T-type (transient) calcium channels open up until voltage reaches -40 L-type calcium channels then open back up