Homeostasis is a process of maintaining certain body states at equilibrium, to ensure normal body function to sustain life. The brain, in conjunction with the autonomic nervous system, or ANS, regulates emotions, appetite, heart rate, breathing and temperature. Regulation is involuntary and thus beyond conscious control. The sympathetic division of the ANS controls the fight-or-flight response, therefore it will increase emotional and organ responses. Conversely, the parasympathetic division of the ANS is the rest-and-relax response that dampens emotional and organ responses, according to the University of New Mexico.
Emotions
The emotions are regulated primarily by the amygdala, an area within the temporal lobe, located just above the ear. Animal studies report that when the amygdala is externally stimulated, monkeys will respond with aggression; however, if extracted, monkeys respond with indifference. Other areas related to emotional response are the cingulate cortex, responsible for focusing attention on emotionally relevant events; the ventral tegmental area, or pleasure center; the basal ganglia, which mediates the desire for reward; and the prefrontal cortex, which plays a role in pleasure and addiction, according to Shippensburg University.
Appetite
Among other functions, the hypothalamus regulates hunger and thirst. The hypothalamus plays many roles in maintaining homeostasis, or the process of maintaining internal equilibrium within the body. Researchers report that the hypothalamus monitors a hormone called lepin, which is secreted from fat cells after eating. If lepin levels rise, appetite decreases, according to Shippensburg University.
Heart Rate
Heart rate is regulated by the autonomic nervous system and the hormones epinephrine and norepinephrine. Receptors in the heart send information to the cardiovascular center in the medulla oblongata. If heart rate must increase, the medulla will send signals via sympathetic nerves to increase heart rate. If heart rate must decrease, the medulla sends signals via parasympathetic nerves to decrease heart rate, according to Springfield Technical Community College.
Breathing
Regions of the brain stem and autonomic nervous system regulate breathing. The medulla oblongata and pons, two regions of the brain stem, send nervous impulses down the spinal cord to stimulate the breathing muscles and smooth the pattern of respiration, respectively, according to the University of New Mexico.
Temperature
The hypothalamus regulates body temperature by monitoring the temperature of the blood. If temperature decreases, the hypothalamus will trigger the release of thyroid stimulating hormone, which in turn releases thyroxin from the thyroid gland. Thyroxin increases metabolism in the body, which produces heat, according to Central Michigan University.
