The atrio-ventricular node (AVN) generates an action potential to stimulate atrial contraction

The tricuspid and the bicuspid valves open due to the pressure exerted by the simultaneous contraction of the atria

Blood moves freely from atrium to the ventricle during joint diastole.

Increased ventricular pressure causes closing of the semilunar valves.

Absence of antibodies, anti-A and anti-B, in plasma

Absence of antigens A and B on the surface of RBCs

Absence of antigens A and B in plasma

Presence of antibodies, anti-A and anti-B, on RBCs

Thrombokinase

Thrombin

Renin

Epinephrine

(A) $$ \to $$ (iii), (B) $$ \to $$ (iv), (C) $$ \to $$ (ii), (D) $$ \to $$ (i)

(A) $$ \to $$ (iv), (B) $$ \to $$ (i), (C) $$ \to $$ (ii), (D) $$ \to $$ (iii)

(A) $$ \to $$ (i), (B) $$ \to $$ (ii), (C) $$ \to $$ (iii), (D) $$ \to $$ (iv)

(A) $$ \to $$ (ii), (B) $$ \to $$ (i), (C) $$ \to $$ (iii), (D) $$ \to $$ (iv)