The autonomic nervous system regulates certain processes in the body, such as blood pressure and respiratory rate. This system operates automatically (autonomously), meaning without the conscious effort of the individual. Disorders of the autonomic nervous system can affect any part or process of the body. They can be reversible or progress over time. The autonomic nervous system is the part of the nervous system that innervates (transmits nerve signals to a region of the body) internal organs, including blood vessels, stomach, intestines, liver, kidneys, bladder, genitals, lungs, pupils, heart, and sweat, salivary, and digestive glands.

The autonomic nervous system has two main divisions:

• Sympathetic
• Parasympathetic»

After receiving information about an organism and its external environment, the autonomic nervous system responds by stimulating the processes of the organism, as can occur through the sympathetic system, or inhibiting them, as can happen through the parasympathetic system.

A neural pathway of the autonomic nervous system consists of two neurons. One is located in the brainstem or spinal cord. It is connected by nerve fibers to the other neuron, which is located in a cluster of neurons (called an autonomic ganglion). The nerve fibers from these ganglia connect to internal organs. Most ganglia of the sympathetic system are located just outside the spinal cord on both sides of it. Ganglia of the parasympathetic system are located near or within the organs they connect with.

The autonomic nervous system controls internal bodily processes such as the following:

• Blood pressure
• Heart rate and respiratory rate
• Body temperature
• Digestion
• Metabolism (thus affecting body weight)
• Water and electrolyte balance (such as sodium and calcium)
• Production of body fluids (saliva, sweat, and tears)
• Urination (more frequent than normal)
• Defecation
• Sexual response

Many organs are primarily controlled by either the sympathetic or parasympathetic system. In some cases, the two systems have opposing effects on the same organ. For example, the sympathetic system increases blood pressure, while the parasympathetic system decreases it. Overall, both systems work together to ensure that the body responds appropriately to different situations.

Generally, the sympathetic system does the following:

Prepares the body for stressful or emergency situations; fight or escape. Therefore, the sympathetic system increases heart rate and the force of cardiac muscle contractions, and widens (dilates) the airways to facilitate breathing. It prompts the release of stored energy, increases muscle strength, produces sweat on the palms, dilates pupils, and causes hair to stand erect. In emergency situations, it slows down less critical bodily processes, such as digestion and urination.

The parasympathetic system performs these functions:

Controls bodily processes during ordinary situations. Typically, the parasympathetic system is dedicated to conservation and restoration. It slows down heart rate and decreases blood pressure. It stimulates the digestive tract to process food and eliminate waste. Energy derived from food transformation is used to restore and build tissues. Both the sympathetic and parasympathetic systems are involved in sexual activity, as are parts of the nervous system that control voluntary actions and transmit skin sensitivity (somatic nervous system).

Conclusion:

Understanding our nervous system is crucial for determining the types of foods that are suitable for the body. The nervous system will indicate which specific nutrients our body needs. Each person is different internally, so it is essential to know the nervous system that controls us to determine the necessary diet for our individual needs.