The autonomic nervous system (ANS) consists of sympathetic, parasympathetic and enteric nervous systems and regulates key functions of the body including the activity of the heart muscle and the smooth muscles (muscles of intestinal tract). Disorders of the sympathetic nervous system (SNS) can lead to severe complications.
The term autonomic implies that the system cannot be controlled by mind. The SNS helps accelerate the heart rate, constrict blood vessels and raise blood pressure, while the parasympathetic nervous system (PNS) helps slow down the heart rate, increases intestinal and gland activities and helps relax sphincter muscles. Enteric nervous system directly controls the gastrointestinal system. The SNS exhibits an active 'stimulating' function while the parasympathetic exhibits mainly a 'relaxing' function. The SNS interlinks skin, blood vessels and organs in the body cavity. The sympathetic chain is present on both sides of the spine and it consists of ganglia.
The autonomic nervous system comprises SNS and PNS, and it plays an important role in two types of situations: emergency situations which generate excessive stress and which require us to 'fight' or take 'flight'; and non-emergency situations when we can simply 'rest' and 'digest'. The autonomic nervous system is important in 'normal' situations too, as it helps maintain normal bodily functions.
Functions of Sympathetic Nervous System
When the body reacts to any kind of danger, the sympathetic ganglia increase muscle tension, send excess blood to brain by reducing the blood flow towards skin and internal organs, make lungs and bronchial tubes widen to give us more oxygen, accelerate heart rate and force, and reduce the motility in the intestine, indicating that we must fight or run away!
Thus SNS is responsible for the effects seen during the fight-or-flight response which include pupil dilation, increased sweating, increased heart rate and increased blood pressure, etc. The other functions of SNS include dilation of bronchioles from lungs, inhibition of peristalsis of digestive tract, increase in the secretion of renin from kidneys, etc. It also promotes ejaculation of penis.
Symptoms of SNS Disorders
- Blood pressure problems like high blood pressure
- Erectile dysfunction in men
- Heart diseases
- Trouble with breathing and swallowing
- Memory loss
- Tremors, seizures
- Loss of muscle strength
- Slurred speech
Causes of SNS Disorders
Nervous system disorder is also known as 'dysautonomia'. If you know the anatomy of the central nervous system, then you will be able to understand the causes of sympathetic nervous system disorders easily.
- Diseases: Many diseases lead to gradual degeneration of nerves, affecting their transmission system. Diabetes and Parkinson's disease can cause SNS disorders.
- Autoimmune Disorders: Autoimmune disorders, wherein immune system considers an organ as a foreign body and attacks it, can lead to SNS disorders.
- Excessive Alcohol Intake: Alcohol abuse is one of the main reasons of SNS disorders
- Brain Injury: Any type of traumatic brain injury can result in SNS dysfunction.
- Brain Infection: When an infection affects brain and spinal cord directly, it can result in SNS disorders.
- Structural Defects: Structural defects, birth defects can cause SNS disorders.
- Immune System Problems: Severe immune system problems can cause SNS disorders.
- Brain Tumors: Brain tumors, benign or malignant, can result in SNS disorders.
- Interrupted Blood Supply to Brain: A stroke, wherein an interrupted blood supply to brain is noticed, can lead to SNS dysfunction.
Sympathetic nervous system dysfunction can lead to a condition called 'fibromyalgia'. Patients of fibromyalgia experience pain in muscles and surrounding structures without any obvious tissue damage. Percentage of women (between the ages of 35 and 60 years) or children suffering from fibromyalgia is quite high. SNS dysfunction can result in Reflex Sympathetic Dystrophy Syndrome or Complex Regional Pain Syndrome (CRPS) which is described as a chronic, painful condition.
The person suffers from moderate to severe pain that is disproportionate to the event (sprain of fracture) which can induce the pain. Often, an arm or a leg is affected by CRPS. A damaged nerve that controls blood vessels and sweat glands can lead to disrupted blood flow, loss of sensation and abnormal skin temperature at the affected area. The person may complain about intense or burning pain at the site and the condition may worsen over time.
This can restrict the movement of the limb and the person may suffer from anxiety and depression. Early detection of the problem helps lower the symptoms. Doctors usually recommend physical therapy and occupational therapy. Pain killers, steroids, medicines to maintain the blood pressure and/or bone loss medications are prescribed by doctors.
If you can learn some stress management techniques like meditation, you may succeed in avoiding nervous system disorders. Doctors prescribe medications to treat SNS disorders, but opting for natural stress relievers is always better. I hope you found the above information helpful and you would take proper care.