Electrical relay station, slowing the electrical current sent by the sinoatrial (SA) node before the signal is permitted to pass down through to the ventricles, is/are:

1. bundle branches	2. Purkinje fibers
3. AV node	4. AV bundle

The period of the cardiac cycle where the greatest amount of ventricular filling occurs is:
1. the first one-third of diastole.
2. the middle one-third of diastole.
3. the last one-third of diastole.
4. ventricular systole.

What is most likely to happen if the SA node suddenly stops generating the impulse?
1. The heart will stop.
2. The ventricles will contract, but the atria will stop.
3. Another part of the heart, possibly the AV node, will become the pacemaker.
4. The atria will keep contracting, but the ventricles will stop.

Pericardial fluid is the serous fluid secreted by the serous layer of the pericardium into the pericardial cavity and it serves to:
1. reduce friction between the pericardial membranes.
2. lubricate the heart valves.
3. replace any blood that is lost.
4. provide oxygen and nutrients to the endocardium.

The SA node is the normal pacemaker of the human heart because its cells
1. spontaneously generate electrical signals about 70 to 80 times per minute.
2. are located in the interventricular septum.
3. generate electrical signals only when stimulated by sympathetic fibers.
4. are not in contact with other cells of the heart.

All the following statements regarding coagulation of blood are correct except:
1. Prothrombinase catalyzes the breakdown of prothrombin to thrombin.
2. Thrombin catalyzes the conversion of fibrinogen to fibrin.
3. Antithrombin inactivates thrombin.
4. Heparin causes fibrinolysis.

What is true regarding blood transfusion and compatibility?
1. A-negative blood can probably be safely donated to a person with A-positive blood.
2. Antibodies against the Rh antigen do not develop unless an Rh-positive person is exposed to Rh-negative blood.
3. The largest percentage of people in India are Rh-negative.
4. Rh-negative mothers cannot have an Rh-positive baby.

RhoGAM injection [one brand of Rh immunoglobulin] is given to Rh-negative mothers to:
1. initiate the synthesis of anti-Rh antibodies in the mother.
2. initiate anti-Rh antibody production in the fetus.
3. prevent the mother from producing anti-Rh antibodies.
4. prevent the fetus from producing anti-Rh antibodies.

A deficiency of plasma proteins would lead to all of the following except:
1. reduced ability to transport iron
2. reduced ability to transport oxygen
3. reduced ability to clot
4. reduced ability to transport molecules such as lipids

Identify the group in which the formed elements of the human blood are arranged in order of increasing size:
1. red blood cell, neutrophil, platelet
2. platelet, red blood cell, neutrophil
3. neutrophil, platelet, red blood cell
4. platelet, neutrophil, red blood cell