Which blood vessels carry blood from different parts of your body to the heart?

How does the pulmonary artery differ from a vein?

Assertion : When there is a fall in the blood pressure due to loss of blood volume,this is compensated by vasoconstriction of veins.
Reason : Veins hold the extra amount of blood which can be shifted to the arteries as required.

$A$ vein differs from an artery in having

The shoulder and forelimb are connected to the heart by which of the following blood vessels?

Which among the three layers of blood vessel wall—$Tunica \text{ intima}$, $Tunica \text{ media}$, and $Tunica \text{ externa}$—is comparatively thin in the veins?