Cardiovascular System

Parasympathetic stimulation (which almost always utilises the vagus nerve) causes a decrease in heart rate.

“Endo-” means on the inside. Epicardium, also known as the visceral pericardium, is on the outside of the heart.

The antigens that react with the recipient’s antibodies which result in agglutination reactions occur on the plasma membrane of the donor’s red blood cells. As plasma does not contain any RBC, an agglutination reaction cannot occur.

Plasma proteins (except fibrinogen) are in plasma and in serum. Serum = plasma minus the clotting factors. Blood cells and platelets are not in plasma.

Ventricular systole is contraction of the ventricles, which does not coincide with relaxation of the atria.

Prothrombinase is the enzyme that converts prothrombin to thrombin (it does not come from platelets).

Choice A describes early diastole. Towards the end of diastole, the atria contract to push any blood they contain into the ventricles.

When a blood vessel wall is stretched, it stimulates baroreceptors to increase their stream of impulses to the vasomotor centre which inhibits it. This means the smooth muscle in blood vessel walls will relax and the vessel diameter will increase, and so BP is reduced.

Antigens are on the surface of RBC. Antibodies (=agglutinins) circulate in the bloodstream and react with (agglutinate) their appropriate antigen.

Rh factor, Rh positive and Rh negative refer to the D antigen only. If the antigen is present on your RBC, you are called Rh positive (you have the Rh factor).