what is vasodilation , diuresis and constrictory effects on blood vessels?

Vasodilation refers to the process of widening of the blood vessels which results in increasing the blood flow. This widening is caused because of the relaxation of smooth muscle cells present inside the walls of those vessels.

Vasoconstriction or constrictory effect on blood vessels refers to the process of narrowing of the blood vessels which results in decreasing the blood flow. This narrowing is caused because of the contraction of smooth muscle cells present inside the walls of those vessels.

Diuresis refers to the increased excretion of urine which may be a result of various medical problems like malfunctioning of kidneys, diabetes, etc