After an extremely stressful day whether it be at work, or at home or just emotionally, all you crave is relaxation. Luckily enough, our body has an inbuilt ‘resting machinery’ which is the parasympathetic nervous system that helps us relax and feel calm. “The parasympathetic nervous system allows you to rest and digest,” says Dr Rohit Pai, consultant neurologist, Kasturba Medical College, and Hospitals, Mangaluru.
Rest and relaxation
To tackle stressful situations, the sympathetic nervous system orchestrates the processes within body to activate what is called the fight or flight response. This triggers a reaction that makes one face or avert the danger. But this response cannot always remain in the ‘switched on’ mode as it leads to several disorders.
Dr Pai says that the parasympathetic nervous system helps the organs to ‘relax’ after a flight and fight response. He explains that the parasympathetic nerves arise from the base of the brain (the brainstem region), and it releases a neurochemical, acetylcholine. This neurochemical reduces heart rate by relaxing the cardiac muscles and aids better digestion by relaxing the muscles of the gut. These nerves also contract the urinary bladder muscles to help pass out urine.
Many experts suggest adoption of relaxation techniques such as yoga, meditation, and a walk in nature for people who suffer from chronic stress or anxiety. These activities tap into the parasympathetic nerves which tells the brain and the body to calm down from extreme stress.
Dr Pai says that disorders that affect the parasympathetic nervous system include:
- Bowel abnormalities like constipation.
- Heart rate abnormalities like irregular and rapid heart rhythm.
- Vasovagal syncope, where there is a temporary lack of blood flow to the brain, and it causes giddiness.
This infographic summarises some of the functions that the parasympathetic nervous system does.