The Autonomic Nervous System: The Regulatory Structure of the Body

The Autonomic Nervous System (ANS) is part of the peripheral nervous system that functions to regulate basic organ processes needed for the maintenance of normal bodily functions. It has two components that include the Sympathetic Nervous System (SNS) and the Parasympathetic Nervous System (PNS). The ANS is defined as a motor system that innervates three major types of tissue consisting of the cardiac muscle, smooth muscle and glands. It also relays visceral sensory information into the Central Nervous System. It then processes it in a way to make alterations in activity of specific autonomic motor outflows, such as those that control heart, blood vessels and other visceral organs.

The ANS regulatory structure helps people adapt to changes in the environment and also adjusts or modifies functions in response to stress and fear. It also regulates the hearts electrical activity and ability to contract, the bronchium’s diameter in the lungs, the movement and work of the stomach, intestine and salivary glands, the secretion of insulin and urinary and sexual functions. It also regulates the sleep-wakefulness cycle.

THE SYMPATHETIC NERVOUS SYSTEM

The Sympathetic Nervous System (SNS) is defined by western Science as a regulation system that operates without the intervention of conscious thought. It is responsible for priming the body for action. The sympathetic nerves are located inside the vertebral column toward the middle of the spinal cord.

The SNS normally function to produce localized adjustments such as sweating and reflex adjustments of the cardiovascular system. The entire SNS is activated during times of stress producing immediate response that is known as the “fight or flight” response. This is characterized by a release of large quantities of epinephrine from the adrenal glands, an increase in heart rate, increase in cardiac output, skeletal muscle vasodilation, cutaneous and gastrointestinal vasoconstriction, papillary dilation, bronchial dilatation and piloerection (goose bumps). All of this is to prepare for imminent danger.

THE PARASYMPATHETIC NERVOUS SYSTEM

The Parasympathetic Nervous System (PNS) serves to sow the heart rate, increase the intestinal and gland activity and relax the sphincter muscles. While the SNS has a “fight or flight” response, the PNS has a “rest and digest” response. The PNS is responsible for the conservation and restoration of energy as it causes a reduction in the heart rate and blood pressure. It also facilitates digestion and absorption of nutrients and consequently causes the excretion of waste products.

The cell bodies of the PNS are located in the spinal cord and in the medulla. Inside the medulla the cranial nerves III, VII, IX, and X form the preganglionic parasympathetic fibers. The cranial nerves are twelve pair of nerves that can be seen on the ventral or bottom surface of the brain.

The effects of the PNS stimulation on specific structures are pupil constriction of the eye muscle, increased saliva production I the salivary glands, increased mucous production in the oral/nasal mucosa, decrease in heart rate and force, bronchial muscle contracted, gastric juice secreted and motility increased in stomach, increased digestion in small intestine, increased secretion and motility in large intestine, increased urine secretion in the kidney and the wall contracted and sphincter relaxed in the bladder.

The Autonomic Nervous System is always working. It is not only active during the “fight or flight” or the “rest and digest” responses. The ANS must continue working in order to maintain normal internal functions. If the ANS does stop working Autonomic failure happens.

AUTONOMIC FAILURE

Autonomic Failure is a result of an imbalance between the Sympathetic and Parasympathetic divisions. Aging is associated with several abnormalities in ANS function that can impair elderly people’s adaptation to stress.

The most common signs of ANS impairment are a drop in blood pressure when the person is standing or stands up suddenly (orthostatic hypotension) or when the blood pressure drops within one hour of eating a meal (postprandial hypotension). The drops in blood pressure cause inadequate blood flow to the brain. It is common for people with this problem to fell dizzy or lightheaded. The condition occurs more in those who have high blood pressure.

There is no cure for Autonomic Disorders, but they can be managed. Several physical measures and drugs can help with Autonomic Failure to prevent low blood pressure or to feel more comfortable during episodes.

The Autonomic Nervous System along with the balance of its two components, the Sympathetic Nervous System and the Parasympathetic Nervous System is a very important factor in the regulation of the bodies’ internal organs. If these systems are not maintained, the body will not function properly.