The volume of blood being pumped by the heart, in particular by the left or right ventricle, per unit time is called as:

1. stroke volume	2. end-diastolic volume
3. ejection fraction	4. cardiac output

QRS complexes on the ECG tracings show that:
1. The atria are depolarizing.
2. The ventricles are depolarizing.
3. The ventricles are repolarizing.
4. The heart is at rest.

The aortic semilunar valve prevents blood from returning to the _____.

In the nodal tissue of the human heart the last to get activated is/are:
1. SA node
2. AV node
3. AV bundle
4. Purkinje fibers

The central cardiac control region is in the _____ of the brain.

Heart murmurs are heart sounds produced when blood flows across one of the heart valves that are loud enough to be heard with a stethoscope. A common cause would be:
1. smoking which weakens the action of the valve
2. ineffective valves allowing blood to leak back through the valve
3. stress from higher blood pressure
4. ineffective signals from the AV node

Blood pressure is the pressure of blood against:
1. the left ventricle
2. the tissue of the organs
3. the capillaries of the lung
4. the wall of a blood vessel

Pulmonary veins return the oxygenated blood from the lungs to:

Erythrocytes in humans are destroyed mainly in:

The most common WBC under normal physiological conditions are: