Function of the Autonomic Nervous System

Function of the Autonomic Nervous System Theories Biological Psychology Print What Is the Autonomic Nervous System? By Kendra Cherry facebook twitter Kendra Cherry, MS, is an author, educational consultant, and speaker focused on helping students learn about psychology. Learn about our editorial policy Kendra Cherry Medically reviewed by Medically reviewed by Claudia Chaves, MD on October 09, 2019 Claudia Chaves, MD, is board-certified in cerebrovascular disease and neurology with a subspecialty certification in vascular neurology. Learn about our Medical Review Board Claudia Chaves, MD Updated on February 03, 2020 Ian Cuming / Getty Images More in Theories Biological Psychology Behavioral Psychology Cognitive Psychology Developmental Psychology Personality Psychology Social Psychology Psychosocial Psychology The autonomic nervous system regulates a variety of body process that takes place without conscious effort. The autonomic system is the part of the peripheral nervous system that is responsible for regulating involuntary body functions, such as heartbeat, blood flow, breathing, and digestion. The Structure of the Autonomic Nervous System This system is further divided into three branches: the sympathetic system, the parasympathetic system, and the enteric nervous system.?? The sympathetic division of the autonomic nervous system regulates the flight-or-fight responses. This division also performs such tasks as relaxing the bladder, speeding up heart rate, and dilating eye pupils.The parasympathetic division of the autonomic nervous system helps maintain normal body functions and conserves physical resources. This division also performs such tasks as controlling the bladder, slowing down heart rate, and constricting eye pupils.The autonomic nervous system is also made up of a third component known as the enteric nervous system, which is confined to the gastrointestinal tract. The autonomic nervous system operates by receiving information from the environment and from other parts of the body. The sympathetic and parasympathetic systems tend to have opposing actions in which one system will stimulate a response where the other will inhibit it. Traditionally, stimulation has been thought to take place through the sympathetic system while inhibition was thought to occur via the parasympathetic system. However many exceptions to this have been found. Today the sympathetic system is viewed as a quickly responding system that mobilizes the body for action where the parasympathetic system is believed to act much more slowly to dampen responses. For example, the sympathetic nervous system will act to raise blood pressure while the parasympathetic nervous system will act to lower it. The two systems work in conjunction to manage the body’s responses depending upon the situation and need.?? If, for example, you are facing a threat and need to flee, the sympathetic system will quickly mobilize your body to take action. Once the threat has passed, the parasympathetic system will then start to dampen these responses, slowly returning your body to its normal, resting state. What Does the Autonomic Nervous System Do? The autonomic system controls a variety of internal processes including:?? DigestionBlood pressureHeart rateUrination and defecationPupillary responseBreathing (respiratory) rateSexual responseBody temperatureMetabolismElectrolyte balanceProduction of body fluids including sweat and salivaEmotional responses The autonomic nerve pathways connect different organs to the brain stem or spinal cord. There are also two key neurotransmitters, or chemical messengers, that are important for communication within the autonomic nervous system: Acetylcholine is often used in the parasympathetic system to have an inhibiting effect.Norepinephrine often works within the sympathetic system to have a stimulating effect on the body. How the Autonomic Nervous System Works Problems With the Autonomic Nervous System When the parasympathetic and sympathetic components of the autonomic nervous systems become out of sync, people can experience an autonomic disorder, also called dysautonomia.   There are numerous types of autonomic disorders, each with its own unique set of symptoms, including:?? Acute autonomic paralysisAfferent baroreflex failureIdiopathic orthostatic hypotensionMultiple system atrophyOrthostatic hypotensionPostprandial hypotensionPure autonomic failureFamilial dysautonomia (Riley-Day syndrome)Secondary orthostatic hypotension Understanding Autonomic Nervous System Dysfunction These disorders can occur alone, or as a result of other conditions that cause disruption in the autonomic nervous system, including: Autoimmune diseaseAlcohol or drug abuseDiabetesParkinsons diseaseCancerChronic fatigue syndromePeripheral neuropathyAgingSpinal cord disordersTrauma Discover How Doctors Diagnose and Treat Dysautonomia Symptoms If you or someone you love is experiencing disruptions in the autonomic nervous system, you may experience one or more of the following symptoms. Some people experience one cluster of symptoms at one time, and another set of symptoms at other times. The symptoms can be fleeting and unpredictable or triggered by specific situations or actions, like after ingesting certain foods or after standing up quickly.?? Dizziness or light-headedness upon standingFatigue and inertiaErectile dysfunctionLack of sweat or profuse sweatingUrinary incontinenceDifficulty emptying the bladderLack of pupillary responseDisturbing aches and painsFaintness (or even actual fainting spells)Tachycardia (fast heart rate)Hypotension  (low blood pressure)Gastrointestinal symptomsNumbness and tinglingSevere anxiety or depression Understanding Autonomic Nervous System Dysfunction Diagnosis and Treatment Diagnosis of an autonomic disorder requires a doctors evaluation, which may include a physical examination, recording blood pressure when the patient is both lying down and standing, testing of the sweat response, and an electrocardiogram. Diagnosing an autonomic disorder is often tricky since both the physical exam and laboratory tests can come back normal. If you suspect that you might have some type of autonomic disorder, its important to find a healthcare provider who doesnt dismiss your symptoms as all in your head, and who is willing to take the prolonged trial-and-error to diagnose and treat your condition. There is currently no cure, however depending on the type of autonomic disorder, there are ways to treat the symptoms. Discover How Doctors Diagnose and Treat Dysautonomia A Word From Verywell The autonomic nervous system plays an important role in the human body, controlling many of the bodys automatic processes. This system also helps prepare the body to cope with stress and threats, as well as returning the body to a resting state afterward. Learning more about this part of the nervous system can give you a better understanding of the processes that underlie many human behaviors and responses.