Histamine release increases vascular permeability. what physical sign is associated with this pathophysiology?
a. swelling
b. decreased cardiac output
c. flushed skin
d. urticaria

The correct option is A. Swelling is the physical sign associated with histamine.

Explanation:

At the site of injury, the mast cells release histamine. The histamine increases the permeability of the vessels and dilates them. This is the reason for the swelling at the site of injury.

As a result of this dilation, several cells of the immune system such as the white blood cells travel to the site of injury and fight the antigens at the site of infection. Gradually, the wound or injury heals and disappears.