Atria can completely empty during ventricular filling due to:
1. A-V node
2. A-V bundle
3. S-A node
4. Purkinje fibers

The arrhythmia that results in cardiac arrest followed by death in the absence of treatment and therefore considered most serious is:
1. Tachycardia
2. Sinus bradycardia
3. Atrial flutter
4. Ventricular fibrillation

The least significant factor for erythropoiesis amongst the following is:
1. vitamin B₁₂
2. vitamin B₆
3. folic acid
4. gastric intrinsic factor

Also sometimes called as the ‘widow maker’ the anterior interventricular artery is a branch of the
1. left circumflex artery.
2. right anterior descending artery.
3. left coronary artery.
4. right coronary artery.

What exactly is an auricle?
1. a sphincter present in an arteriole.
2. an extension of the atrial wall.
3. part of a heart valve.
4. part of nodal tissue of the heart.

Under normal physiological conditions a higher cardiac output can be achieved by a higher:
1. extracellular ${\mathrm{K}}^{+}$ concentration
2. blood pressure in the systemic circulation
3. venous return
4. parasympathetic tone

Vagotomy [cutting of vagus nerve] would lead to:
1. reduced heart rate
2. increased heart rate
3. reduced strength of contraction
4. increased secretion of acetylcholine

Which statement concerning blood viscosity is correct?
1. The viscosity of blood is less than the viscosity of water.
2. Blood viscosity is due to the presence of the plasma proteins and erythrocytes.
3. The higher the blood viscosity the easier the heart has to work to move blood through the vessels.
4. Anemia increases blood viscosity.

The cytoplasmic granules released by thrombocytes during platelet plug formation, which attract more platelets to the plug are:
1. prostacyclin and NO
2. erythropoietin and bilirubin
3. heparin and plasmin
4. ADP and thromboxanes

A person comes to the ER with a need of blood transfusion. How would you determine his blood type?
1. By mixing his blood with the blood of another person of known blood type and if there is no reaction they are the same type.
2. By looking at red blood cells under a microscope to see what kind of antigens are on their membranes.
3. By checking to see which plasma antibodies a person has and he won't have antibodies against his own blood type.
4. By mixing the blood with different antibodies to see which ones cause the red blood cells to agglutinate.