The autonomic nervous system is a division of the central nervous system, which controls involuntary actions. This system is vital to your overall well-being and longevity. In today’s article, we will go over what the autonomic nervous system is, the subdivisions of the ANS, and what triggers the ANS.
What Is The Autonomic Nervous System?
The autonomic nervous system is the part of your nervous system that controls involuntary actions. These actions include your heart rate and the widening or narrowing of your blood vessels. Suppose something goes wrong with the autonomic nervous system. In that case, it can lead to the following problems:
- Blood pressure problems
- Heart problems
- Trouble with breathing and swallowing
- Erectile dysfunction
Disorders in the autonomic nervous system can occur alone or as a symptom of another disease. Some disorders can be temporary while others will worsen over time. Autonomic nervous system disorders can get better when an underlying disease is treated, however, most have no cure.
What Does The Term Autonomic Mean?
Autonomic means acting or occurring involuntarily. That’s why the autonomic nervous system was formerly referred to as the vegetative nervous system. It acts unconsciously while helping regulate heart rate, digestion, respiratory rate, pupillary response, urination, and sexual arousal. It is also in control of the fight-or-flight response.
This system is regulated by reflexes through the brainstem to the spinal cord and organs. Functions include control of respiration, cardiac regulation, vasomotor activity, and certain reflex actions like coughing and sneezing. There are different subsystems within the autonomic nervous system that we will discuss later in the article.
What Is The Role Of The Autonomic Nervous System?
The nervous system's primary role is to regulate the internal environment of the body. Without it, it would be impossible for the body to maintain homeostasis. This is the relatively stable and balanced conditions inside the body that are necessary to support life. Some of the bodily functions that homeostasis regulates include:
- Blood temperature
- Blood pressure
- Heart rate
- Blood glucose levels
- Blood acidity levels
The autonomic nervous system will receive information from the environment and other parts of the body to regulate the activity of the organs. Another critical function of the autonomic nervous system is that it helps prepare the body for fight-or-flight responses.
What Are The 2 Autonomic Nervous Systems?
The autonomic nervous system has two major divisions. Both of these divisions work in unison to help maintain homeostasis, but they perform separate tasks. The two main divisions are the sympathetic division and parasympathetic division. Here’s what you need to know about these divisions:
- Sympathetic division - This division prepares the body for stressful or emergency situations. The sympathetic division increases heart rate and widens the airways to make breathing easier. During this process, the body will release stored energy, causing muscular strength to be increased
- Parasympathetic division - This division controls body processes during ordinary situations. The parasympathetic division slows the heart rate and decreases blood pressure. It will stimulate the digestive tract to process food. Energy from this food is used to restore and build tissues
The body uses two neurotransmitters, acetylcholine and norepinephrine, to communicate within the autonomic nervous system.
What Are The 4 Main Parts Of The Nervous System?
Just like the subdivisions of the autonomic nervous system, the divisions of the nervous system all work to help maintain proper homeostasis throughout the body. We already know one of the main parts of the nervous system is the autonomic system. Here are some of the other parts of the nervous system:
- Peripheral nervous system - This system includes all of the parts of the nervous system outside of the brain and spinal cord
- Somatic nervous system - This is a division of the peripheral nervous system that includes all of the voluntary efferent neurons. This system is the only consciously controlled part of the peripheral nervous system and is responsible for stimulating skeletal muscles in the body
- Enteric nervous system - This is another division of the autonomic nervous system that is responsible for regulating digestion and the function of digestive organs. The enteric nervous system is an immune system
All of these divisions work together to help keep functions throughout the body operating at 100%.
What Triggers The Autonomic Nervous System?
There are several different situations that can trigger the autonomic nervous system. In situations that are associated with stress, such as a depressive disorder, the sympathetic nervous system can be continuously activated. This process can happen without the normal counteraction of the parasympathetic nervous system.
How Does The Autonomic Nervous System Control Breathing?
As mentioned earlier in the article, the autonomic nervous system controls involuntary actions, such as breathing. Breathing is an automatic and rhythmic act produced by networks of neurons in the brain. The interconnection of brain-stem neurons sets the rhythm and length of each phase of respiration.
The respiratory system has the ability to adjust breathing patterns to changes in both the internal milieu and external environment. Ventilation will either increase or decrease depending on swings in carbon dioxide production and oxygen consumption caused by the metabolic rate. It can also compensate for disturbances that affect the mechanics of breathing.