Coordination and control

• Homeostasis maintains optimal conditions for enzyme action throughout the body, as well as cell functions. For example, body temperature and water levels.
• The human nervous system consists of the central nervous system (the brain and spinal cord) and the peripheral nervous system (nerve cells that carry information to or from the central nervous system)
• A hormone is a chemical substance

  , produced by a gland and carried in the blood stream, which alters the activity of specific target organs
• The adrenaline hormone is released by the adrenal gland