18. Cardiovascular System: the Heart

Which of the following would lead to a decrease in heart rate?

Cardiac output is __________.

Cardiac output is equal to the (a) difference between the end-diastolic volume and the end-systolic volume, (b) product of heart rate and stroke volume, (c) difference between the stroke volume at rest and the stroke volume during exercise, (d) stroke volume less the end-systolic volume, (e) product of heart rate and blood pressure.

What three factors regulate stroke volume to ensure that the left and right ventricles pump equal volumes of blood?

Discuss how the Frank-Starling law of the heart helps to explain the influence of venous return on stroke volume.

Name three different factors that increase heart rate.

Differentiate between stroke volume and cardiac output. How is cardiac output calculated?

What factors influence cardiac output?

Vern is suffering from cardiac arrhythmias and is brought into the emergency room of a hospital. In the emergency room he begins to exhibit tachycardia and as a result loses consciousness. Explain why Vern lost consciousness.

The following measurements were made on two individuals (the values recorded remained stable for 1 hour): Person 1: heart rate, 75 bpm; stroke volume, 60 mL Person 2: heart rate, 90 bpm; stroke volume, 95 mL Which person has the greater venous return? Which person has the longer ventricular filling time?

Karen is taking the medication verapamil, a drug that blocks the calcium channels in cardiac muscle cells. What effect should this medication have on Karen's stroke volume?