What are the functions performed by histamine in the body ?

Explanation

Histamines are the potent vasodilators , and performs various functions . For example , histamine contracts the smooth muscles in the bronchi and gut (to which pateints of asthama are very sensitive) and relaxes other muscles such as those in the walls of fine blood vessels .
Histamine is also responsible for the nasal congestion associated with common colds , coughs , allergic response to pollens etc.