Nervous system consists of central and peripheral nervous system i.e., CNS and PNS. CNS includes brain and spinal cord. PNS includes somatic and autonomic nervous system (ANS). ANS includes sympathetic and parasympathetic nervous systems. These systems work to maintain the body during stress. Sympathetic system works during stress and parasympathetic works to get the body back to normal. Sympathetic effect is decrease in saliva, relaxation of bronchioles and decreased stomach peristalsis. Parasympathetic is opposite to these effects. Pancreatic hormones glucagon and insulin are responsible for sugar metabolism.