What is the need for a system of control and coordination in an organism?

Nervous system and endocrine system are responsible for control and coordination of complex, multicellular human body with multiple organ systems of complex functioning. Endocrine secretions (hormones) regulate proper growth and development and functioning of different organs. Nervous system enables us to respond to our surroundings and to perform daily activities. It does so by sensing external and internal stimuli followed by a relay of sensory information to CNS (Central Nervous System) for processing and generation of motor output, i.e., involuntary and voluntary actions.