Involuntary and unconscious activities happening in your body need to be controlled by something, right? Here’s where the Autonomic Nervous System (ANS) comes into the picture – the set of neuron fibers responsible for controlling and coordinating automatic functions like heart rate, digestion, and respiratory rate.
The Autonomic Nervous System (ANS)
The ANS is the division of the central nervous system that governs unconscious activities in the body. It is sub-classified into two branches – the sympathetic and the parasympathetic nervous systems. These work in tandem to maintain the body’s internal environment to ensure it works effectively and efficiently.
The Sympathetic Nervous System
The sympathetic nervous system helps the body deal with stress situations, a fight-or-flight response to anything perceived as dangerous or threatening. The body gears up to face the danger or threat, with the SNS kicking in and controlling key functions, making sure the body is prepared for action.
Some of the physiological changes caused by the SNS include:
- Increased heart rate
- Dilated pupils
- Inhibited digestion
- Increased respiratory rate
- Constricted blood vessels
The SNS’s response is nothing but a reaction to external stimuli, with the primary goal of setting the body up to tackle anything that may cause danger or threat.
The Parasympathetic Nervous System
The parasympathetic nervous system, commonly known as the rest-and-digest branch, is responsible for relaxing the body and works to counteract the effects of the sympathetic system. It is the functional opposite of the sympathetic nervous system, restoring the body to normalcy after a threat is averted.
The PNS slows down the heart rate and breathing, increases the digestive tract’s activity, and stimulates the urinary system to eliminate waste products. These functions are all controlled by a single nerve, commonly referred to as the “vagus nerve.”
The Role of the ANS
The autonomic nervous system’s functions include controlling glands responsible for producing hormone secretion, which helps in regulating blood sugar, electrolytes, blood pressure, and body temperature. It also helps the body cope with changes in the external environment and protect itself from any harm.
The ANS and Blood Pressure
The autonomic nervous system influences the activities of the heart and the blood vessels, and it does so by regulating blood pressure. Blood pressure regulation is necessary to ensure that our organs receive an adequate amount of blood to function correctly.
There are two ways the ANS controls blood pressure:
- The sympathetic system increases blood pressure, primarily by increasing heart rate and constricting blood vessels.
- The parasympathetic system reduces blood pressure by decreasing heart rate and dilating blood vessels.
A balance between these two branch systems is necessary to maintain proper blood pressure. A malfunction in either can lead to hypertension or hypotension.
The ANS and Digestion
The ANS plays a significant role in the digestive system, promoting digestion, absorption, and the movement of food, including the elimination process.
When food is consumed, the parasympathetic system works to activate the digestive tract’s muscles and increase digestive enzyme production while decreasing heart rate and respiratory rate. The sympathetic system, conversely, inhibits digestive function, an example being decreased digestive activity under stressful situations.
The ANS and Respiratory Function
The ANS regulates the function and control of the respiratory systems by interacting with the muscles that control the diaphragm’s movement and chest wall. Breathing rate is mainly influenced by the status of the body’s metabolic rate, carbon dioxide levels, and oxygen levels.
When the body’s metabolic demands increase, the sympathetic system works to increase respiratory rate and depth; conversely, the parasympathetic system works to decrease respiratory rate and depth when metabolic demand decreases, such as in relaxing situations.
The Effects of ANS Dysfunction
An ANS dysfunction can result in problems such as incontinence, temperature control, gastrointestinal issues, problems with heart rate and blood pressure may arise. Some common ANS dysfunctions include:
- Orthostatic hypotension
- POTS (postural orthostatic tachycardia syndrome)
- Raynaud’s disease
- Gastroparesis
- Chronic constipation
In some circumstances, dysfunction of the ANS may lead to conditions such as multiple system atrophy (MSA), autonomic neuropathy, and multiple sclerosis (MS).
In Conclusion
The ANS is a critical part of the nervous system involved mainly in managing various automatic functions of the body. Its regulation of the body’s internal environment is necessary to ensure our organs, tissues, and systems work effectively and efficiently.
Common Questions About ANS
1. What does the autonomic nervous system regulate?
The ANS regulates the internal environment of the body by controlling heart rate, blood pressure, digestion, blood sugar levels, and body temperature
2. How does the ANS respond to stress?
The ANS has two responses to stress – fight or flight. The sympathetic system enables the body to respond by increasing the heart rate, dilating pupils, and inhibiting digestion.
3. What is the difference between the sympathetic and parasympathetic nervous systems?
The sympathetic system prepares the body for action in crisis situations, while the parasympathetic system works to restore the body to normalcy after the crisis has passed.
4. What happens when the ANS is not functioning correctly?
Dysfunction of the ANS may lead to conditions such as gastroparesis, orthostatic hypotension, and chronic constipation.