If cardiac output is $4200 \text{ ml/min}$,then $x$ beats/min is the heart rate and $y$ is the term for pulse rate.

Consider the following four statements regarding the human circulatory system:
$(a)$ Arteries have thick walls and have a smaller lumen compared to veins.
$(b)$ Angina is a sudden chest pain.
$(c)$ In the $ABO$ blood grouping system,a person with $AB$ blood group can donate blood to anyone.
$(d)$ Calcium ions play an important role in blood clotting.
Which two of the above statements are correct?

Choose the correct option:
$(1)$ Depolarization of the ventricles induces the $QRS$ / $T$ waves.
$(2)$ Incomplete double circulation is seen in reptiles / birds.

The $pH$ of blood in an artery and a vein is:

Which of the following organs is known as the blood bank of the body?

Identify the correct option:

Vessel	Renal vein	Pulmonary artery	Hepatic portal vein	Main Aortic arch
$(a)$	$PO_2 = 95 \, mm \, Hg, PCO_2 = 40 \, mm \, Hg$	Less concentration of ions in blood	More fatty acid and glycerol in the blood	$PO_2 = 95 \, mm \, Hg, PCO_2 = 40 \, mm \, Hg$
$(b)$	Blood $pH = 7.4$	Less excretory substances than other blood vessels	More nutritive substances	More oxygen than pulmonary artery
$(c)$	Less excretory wastes	$PO_2 = 40 \, mm \, Hg, PCO_2 = 45 \, mm \, Hg$	Less amount of fatty acid and glycerol compare to other blood vessels	More excretory substances than renal vein
$(d)$	More oxygen than pulmonary artery	More excretory waste than renal vein	$PO_2 = 95 \, mm \, Hg, PCO_2 = 40 \, mm \, Hg$	Less excretory waste than hepatic portal vein