Histamine released from mast cell granules produces which pair of effects on local blood vessels?

1. The released contents of injured cells stimulate mast cells to release granules holding histamine, leukotrienes and prostaglandins. 2. Histamine increases the diameter of local blood vessels, which is vasodilation, and blood flow rises as a result. 3. Histamine also increases the permeability of local capillaries, so plasma leaks out and forms interstitial fluid. 4. The extra flow gives the heat and redness of inflamed tissue and the leaked fluid gives the swelling. 5. Any option built on constriction reverses the vessel response and could not produce those signs. _Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 21 "The Lymphatic and Immune System", section 21.2 Barrier Defenses and the Innate Immune Response_