The human body is comprised of several different systems that must work together to carry out the various processes necessary for good health. According to the University of Washington, the nervous system controls many of these various systems directly. For example, when the body needs to alter the beating rate of the heart or blood pressure, the brain sends the message to do so via nerve impulses.
Another example of direct control via the nervous system involves the endocrine system. The University of Washington explains that the hypothalamus, a component of the brain, regulates and controls the pituitary gland, which produces hormones. Hormones themselves are a mechanism by which the body coordinates discrete systems, according to the BBC. For instance, when it is time for a person to exhibit secondary sexual characteristics, the body produces the appropriate hormones.
Controlling the body’s different systems helps achieve a consistent internal environment. This internal balance is called homeostasis, and the BBC explains that hormones and the nervous system are responsible for maintaining it. For example, after a meal, the pancreas secretes insulin to maintain a relatively stable blood sugar level. Body temperature is also an important parameter to regulate, and the body does so by altering the blood flow patterns to the skin.