NURS 283: CARDIOVASCULAR TEST GUIDE WITH
ANSWERS
I. Define preload, afterload, and contractility.
• Preload: refers to the mechanical state of the heart at the end of diastole
with the ventricles at their maximum volume.
• Afterload: Is the force required to eject blood from the ventricles and is
determines by the peripheral resistance to the opening of the semilunar
valves.
o Example: Afterload is increased by a high diastolic pressure resulting from
excessive vasoconstriction.
• Contractility:
II. How does blood flow through the heart?
1. The two atria are relax and are filled with blood (from the inferior and
superior venae cavae into the right atrium, and from the pulmonary veins into
the left atrium).
2. AV valves open as the pressure of the blood in the atria increases and the
ventricle are relaxed.
3. Blood flows into the ventricles, almost emptying the atria.
4. The conduction system stimulates the atrial muscle to contract, forcing
any remaining blood into the ventricles.
5. Atria relaxes
6. The two ventricles begin to contract, and pressure increase in the ventricles.
7. AV valves close
8. For a brief moment, all valves are closed, the ventricular myocardium continues
to contract, building up pressure in this isovolumetric phase (no change in blood
, NURS 283: CARDIOVASCULAR TEST GUIDE WITH
ANSWERS
volume in the ventricles).
9. The increased pressure opens the semilunar valves; blood is forced into
the pulmonary artery and aorta.
10. At the end of the cycle, the atria have begun to fill again, the ventricles relax, and
the aortic and pulmonary valves close to prevent backflow or blood, and the cycle
repeats.
III. What determines cardiac output?
• Cardiac output is the volume of blood ejected by the ventricle in one minute
and depends on the heart rate and stroke volume, the volume pumped from
one ventricle in one contraction. This means that at rest, the heart pumps into
the system an amount equal to the total blood volume in the body every
minute, which is remarkable feat. When necessary, the normal heart can
increase its usual output by four or five times the minimum volume.
Cardiac output = Heart Rate x Stroke Volume
Amount of blood pumped Number of contractions Amount of blood ejected
by each ventricle in min. of the ventricles each from each ventricle with
minute each contraction.
ANSWERS
I. Define preload, afterload, and contractility.
• Preload: refers to the mechanical state of the heart at the end of diastole
with the ventricles at their maximum volume.
• Afterload: Is the force required to eject blood from the ventricles and is
determines by the peripheral resistance to the opening of the semilunar
valves.
o Example: Afterload is increased by a high diastolic pressure resulting from
excessive vasoconstriction.
• Contractility:
II. How does blood flow through the heart?
1. The two atria are relax and are filled with blood (from the inferior and
superior venae cavae into the right atrium, and from the pulmonary veins into
the left atrium).
2. AV valves open as the pressure of the blood in the atria increases and the
ventricle are relaxed.
3. Blood flows into the ventricles, almost emptying the atria.
4. The conduction system stimulates the atrial muscle to contract, forcing
any remaining blood into the ventricles.
5. Atria relaxes
6. The two ventricles begin to contract, and pressure increase in the ventricles.
7. AV valves close
8. For a brief moment, all valves are closed, the ventricular myocardium continues
to contract, building up pressure in this isovolumetric phase (no change in blood
, NURS 283: CARDIOVASCULAR TEST GUIDE WITH
ANSWERS
volume in the ventricles).
9. The increased pressure opens the semilunar valves; blood is forced into
the pulmonary artery and aorta.
10. At the end of the cycle, the atria have begun to fill again, the ventricles relax, and
the aortic and pulmonary valves close to prevent backflow or blood, and the cycle
repeats.
III. What determines cardiac output?
• Cardiac output is the volume of blood ejected by the ventricle in one minute
and depends on the heart rate and stroke volume, the volume pumped from
one ventricle in one contraction. This means that at rest, the heart pumps into
the system an amount equal to the total blood volume in the body every
minute, which is remarkable feat. When necessary, the normal heart can
increase its usual output by four or five times the minimum volume.
Cardiac output = Heart Rate x Stroke Volume
Amount of blood pumped Number of contractions Amount of blood ejected
by each ventricle in min. of the ventricles each from each ventricle with
minute each contraction.
