The Parasympathetic Nervous System (PSNS) is part of the autonomic nervous system (ANS), which is responsible for involuntary and unconscious bodily activities such as breathing, digestion, and regulation of heart rate. Along with the Sympathetic Nervous System, it makes up the two components of the ANS, with one system typically working to facilitate arousal and the other to slow it down. The PSNS is typically associated with restorative, slow body processes and is observed as the body’s ‘rest-and-relax’ system. The PSNS is responsible for the ‘rest-and-digest’ processes that human beings experience during moments of rest or calm. The PSNS can be activated when a person lays down or takes a break and is responsible for slowing down the heart rate, increasing salivation and gastric juice secretion, and relaxing muscles. Its effects help individuals conserve energy and reduce stress by lowering cortisol, a hormone associated with the body's stress response. The PSNS is composed of several cranial nerves, including the oculomotor nerve, facial nerve, glossopharyngeal nerve, vagus nerve, and accessory nerve. These cranial nerves play a crucial role in controlling the body’s response to stress and providing homeostasis. The facial nerve is responsible for controlling taste, salivation, and facial movement. The Glossopharyngeal nerve is responsible for controlling the tongue, throat, and parotid glands. The vagus nerve is responsible for controlling the heart, lungs and digestive tract. Finally, the accessory nerve is responsible for controlling some of the muscles of the shoulder and back. These cranial nerves receive neural impulses from the hypothalamus, which is responsible for releasing hormones that help regulate body temperature and behavior. This system helps to maintain balance in the body, regulating activities such as digestion, respiration, and heart rate. As such, an imbalance in the PSNS can lead to a variety of health problems including digestive issues, respiratory issues, and cardiovascular problems. In conclusion, the Parasympathetic Nervous System is an important part of the human body. It is responsible for controlling slow, restorative body processes and helping maintain homeostasis. It is composed of many cranial nerves that receive stimuli from the hypothalamus to regulate the body’s response to stress. An imbalance of this system can lead to a variety of health problems, so it is important to take measures to maintain one’s PSNS health.