What role do histamine and bradykinin play in the healing process?

• A. They decrease the permeability of blood vessels
• B. They increase the permeability of small blood vessels
• C. They help in forming blood clots
• D. They promote leukocyte migration

Answer: (B)

Histamine and bradykinin are critical components in the inflammatory response, particularly in the early stages of healing. They play a significant role in vascular permeability. Specifically, these substances increase the permeability of small blood vessels, allowing fluid and essential immune cells to exit the bloodstream and enter the surrounding tissue where injury or inflammation has occurred.

This increased permeability is vital for the healing process because it facilitates the movement of leukocytes to the site of injury, promoting an effective inflammatory response. The enhanced blood vessel permeability contributes to the redness and swelling typically observed during inflammation, signaling the body to focus its healing efforts in the affected area. Therefore, the choice highlighting their role in increasing vascular permeability accurately reflects their function in the healing process.