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 .
The lymphatic system consists of lymphatic organs, a conducting network of lymphatic vessels, and the circulating lymph. The thymus and the bone marrow constitute the primary lymphoid organs involved in the production and early clonal selection of lymphocyte tissues.ymphocytes are concentrated in the lymph nodes. The spleen and the thymus are also lymphoid organs of the immune system. The tonsils are lymphoid organs that are also associated with the digestive system.