There is a system of our nervous system which is based on all the actions of the body which are not in our body’s control but they are still performed by different organs of the body. This system is named an Autonomic Nervous System. The body functions which are controlled by this system include heartbeat, blood circulation, urination, digestion, breathing, maintaining body temperature, and fluid balance inside the body and sexual responses. The Autonomic Nervous system has two parts:
- The sympathetic autonomic nervous system
- The parasympathetic autonomic nervous system
Our main focus in this article is sympathetic autonomic nervous system but we will also describe the parasympathetic autonomic system as well.
The parasympathetic autonomic nervous system
The location of this system is between the medulla and spinal cord. This system primarily controls the body’s functions during rest. It is the rest and digest system. When the fight or flight situation is over it is the parasympathetic nervous system that slows down the breathing, heartbeat, blood pressure, increases gland and intestinal activity.
The sympathetic autonomic nervous system
This system controls bodily functions during stress such as fight or flight situations. We can say that it is the sympathetic nervous system through which a person is able to respond to danger and save himself.
For e.g running while seeing predators, hiding or escaping by seeing the thieves.
This sympathetic system is located near the lumbar and thoracic regions in the spinal cord. The sympathetic nervous system is composed of many nerve cells that are found in peripheral and central nervous systems. This allows the sympathetic system to save the organism in danger by activating multiple responses at the same time, failing which can lead to the death of the person.
Functions of sympathetic system
The sympathetic system is mainly responsible for maintaining body homeostasis during different situations. For example, it initiates sweating to reduce body temperature during the heat, it also changes heartbeat according to body activity level. However, it is known for controlling body actions during fight or flight situations. Let us describe each function of this system briefly.
- Fight or flight :
When the body sees danger, the sympathetic system gets activated and prepares the body for emergency situations. The body responds by increasing heartbeat and blood circulation flows towards skeletal muscles. The respiration rate is also increased to inhale more oxygen. The digestive tract actions are slowed down. Blood vessels are dilated. Eye pupils are also dilated. The action of the lacrimal gland is inhibited. Loss of hearing due to auditory exclusion and tunnel vision occurs. Body shakes due to disinhibition of spinal reflexes. All this happens when your body is in a fight situation such as aggression and flight such as escaping or fleeing from a predator or harmful object.
- Body temperature regulation:
Regulating body temperature or homeostasis is also a feature of the sympathetic nervous system. It regulates the body temperature at the time of need. Such as during cold weather, it enhances the heat production by utilizing fat stock inside the body. During the warm weather, the heat from the body is lost through sweating, and body temperature is regulated.
- Cardiovascular functions:
Whenever the body posture is changed, it is the duty of the sympathetic nervous system to regulate the cardiovascular system accordingly. For e.g during exercise, the body is focused to provide more oxygen and nutrients to skeletal muscles and also remove the waste material produced by the metabolism. People whose sympathetic system is weakened by any disorder, feel the ailment as dizziness whenever they try to change their posture.
In All of these actions, a sympathetic and parasympathetic system works alternatively. When the fight or flight situation is over then the parasympathetic system takes control of the body and mediates all the functions activated by the sympathetic nervous system.