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 .
REPRODUCTIVE SYSTEM. CELLS. TISSUES. ORGANS. FIND OUT MORE. Our body structures are arranged into several different systems, each with its own specific function. The smallest units in the body are CELLS, which share certain characteristics. These tiny structures are collected into TISSUES, which are themselves arranged into ORGANS. Different body systems consist of collections of cells, tissues, and organs with a common purpose.