Autonomic Nervous System
The autonomic system is the part of the peripheral nervous system responsible for regulating involuntary body functions, such as blood flow, heartbeat, digestion, and breathing. In other words, it is the autonomic system that controls aspects of the body that are usually not under voluntary control. This system allows these functions to take place without needing to consciously think about them happening.
Autonomic Nervous System is further divided into two branches:
- The sympathetic system regulates the flight-or-fight responses. This system prepares the body to expend energy and deal with potential threats in the environment. When the action is needed, the sympathetic system will trigger a response by speeding up the heart rate, increasing breathing rate, increasing blood flow to muscles, activating sweat secretion, and dilating the pupils. This allows the body to respond quickly in situations that require immediate action. In some cases, we might stay and fight the threat, while in other cases we may instead flee from the danger.
- The parasympathetic system helps maintain normal body functions and conserve physical resources. Once a threat has passed, this system will slow the heart rate, slow breathing, reduce blood flow, to muscles and constrict the pupils. This allows us to return our bodies to a normal resting state.