Question

Which of the following steps initiates an inflammatory response?

A) Arterioles dilate.
B) Capillary permeability increases.
C) Leukocytes migrate to the infection.
D) Macrophages secrete cytokines.
E) Macrophages engulf the debris or foreign material.

Answer 1

The step that initiates an inflammatory response is when macrophages secrete cytokines, leading to increased blood vessel dilation and permeability, which allows leukocytes to reach the site of infection or injury.

Step-by-step explanation:

The initiation of an inflammatory response occurs when tissue injury or infection prompts the release of chemical signals. Among the suggested steps, macrophages secret cytokines which is the correct answer that starts the inflammatory response. These cytokines help to trigger inflammation by causing blood vessels (capillaries) to dilate and become more permeable. This increased blood flow and capillary permeability allow leukocytes, such as neutrophils and macrophages, to migrate to the site of infection, where they can combat pathogens through phagocytosis and help repair damaged tissue.