Which vessels vasoconstrict in response to epinephrine and norepinephrine? which vessels vasoconstrict in response to epinephrine and norepinephrine? systemic arterioles coronary arterioles capillaries venules?

The answer is capillary venules. The hormones are also used to treat superficial bleeding because the resultant vasoconstriction reduces blood flow in the venules, hence reduce bleeding. The hormones are also used to increase blood pressure and treat anaphylaxis. The hormones induce constriction when bound to alpha adrenergic receptors such as the capillary venules. They cause dilation when bound to beta-adrenergic receptors such as in arteries.

Making and breaking of bonds are examples of chemical reaction. Chemical bonding is the process in which chemical bonds are formed and the process of breaking of bonds is called chemical dissociation.

It takes energy to break the chemical bond between the reactants and the making of new bonds gives the energy. Therefore breaking of bond is an endothermic process and making of bond is an exothermic process.

Bonds breaks when a particular amount of energy is given to it and this energy is called the bond energy.