Growth factors and cytotoxic factors also regulate inflammatory response. These cytokines and other chemicals recruit immune cells to the site of infection and promote healing of damaged tissue following the removal of pathogens. NFkB plays a key role in regulating the immune response to infection.
Stomata facilitate the exchange of gases in the leaf. Carbon dioxide (CO 2 ) diffuses into the leaf through the stomata for use in photosynthesis, and oxygen (O 2 ), the waste product of photosynthesis, diffuses out of the leaf through stomata. Stomata are also crucial for water transport through the xylem .
Stroma: The supportive framework of an organ (or gland or other structure), usually composed of connective tissue. The stroma is distinct from the parenchyma, which consists of the key functional elements of that organ.