The cardiac action potential is substantially longer than a neuron potential due to:   Question options:   myocardial contractility   spontaneous depolarization   gap junctions   Ca++ entry

During which phase of the cardiac cycle is the ST segment present on an EKG? Group of answer choices Atrial systole Isovolumetric ventricular contraction Rapid ventricular ejection Isovolumetric ventricular relaxation Rapid ventricular filling

Inadequate tissue perfusion in hypovolemic shock occurs due to:   Question 9 options:   Decrease in cardiac blood flow due to valvular disease or pericarditis   Increase in intravascular volume leading to fluid volume overload   Decrease in intravascular volume leading to decreased cardiac output   Decrease in peripheral vascular resistance leading to decrease flow

Fill in the blank:  Of the ions that affect heart action, the most important are ions of calcium and ________________________.

The role of calcium currents in cardiac contractile cells is to .  The role of calcium currents in cardiac conductive cells is to .    Choose between: release neurotransmitter, bring the membrane potential to threshold, initiate action potential, prolong action potential, terminate action potential

isovolumetric contraction isovolumetric relaxation ventricular filling ventricular ejection closed rises S1 drops depolarize S2 The first phase of the cardiac cycle is . This is when a lot of blood is in the atria, which causes atrial pressure to be higher than the ventricles. The atrioventricular valves open, and blood moves from the atria to the ventricles. At the end of this phase, the atria contract to maintain pressure and blood flow into the ventricles. As blood leaves the atria, the pressure in the atria As blood enters the ventricles, the pressure in the ventricles Towards the end of this phase, the pressure in the ventricles will exceed the pressure in the atria. At this point, the heart enters the second phase of the cardiac cycle: At this point, the AV valves shut, and we hear . The atria repolarize and the ventricles (due to the QRS complex of the ECG), causing ventricular contraction. Although contracting, it is not yet moving blood into the arteries. All 4 heart valves…

The cardiac action potential is substantially longer than a neuron potential due to: spontaneous depolarization Ca++ entry gap junctions myocardial contractility

Explain how the blood volume in the left ventricle changes throughout the cardiac cycle in response to changes in left atrial pressure, left ventricular pressure, and aortic pressure. Start with the relaxation of the ventricle at the beginning of diastole.

Discuss the events in an action potential that are generated in cardiac contractile cells.

If you have a resting heart rate of 125 beats/min or bpm then you have: a normal heart rate, bradycardia, or tachycardia