Nervous system is the special system that controls and regulates all the other systems of the body to make them function as per the requirements of the body. The nervous system keeps this control mechanism on under all the situations even under the situations of extreme stress and strain. There are two main divisions of the nervous system. These are called the central nervous system and the peripheral or the autonomous nervous system. The central nervous system consists of brain, medulla, spinal chord and the nerves. The autonomous nervous system consists of two chains of knot like structures called the ganglia running along the two sides of the backbone.
The brain is divided into two main parts known as the cerebrum or the large brain and the cerebellum or the small brain. There is a central portion of the brain also called the brain stem, which is divided into the medulla and the pons. The brain including the brain stem is covered with a protective sheath called the meninges. The cerebrum is the largest part of the brain. It consists of two cerebral halves also called the left and the right part of the brain. These two parts are separate but are connected below by a bundle of nerve fibres and it is called corpus callosum. The outer region of the cerebrum consists of grey matter also called cerebral cortex. Below the cortex is a bundle of nerve fibres also known as the white matter of the brain.
The cerebrum has specialized cells where various stimuli from different sense organs like sight, smell, hearing, taste and touch are received and registered. This part of the brain also decides the individual's response to these stimuli. The abstract functions of memory, emotions, and consciousness are also controlled by the cerebrum. The cerebellum or the small brain is concerned with maintaining the balance of the body and coordination in the movements of the various body parts. The centres of control that control the action of the heart and the lungs are located in the portion of the brain, which is known as the medulla or the brain stem. The brain stem contains many important nerve centres for the respiratory centre, cardiac centre, vasomotor centre or the centre pertaining to blood vessels and the salivary or degluitition centre.
The spinal chord is a rope like mass of nervous tissue running from the medulla downwards. It is very delicate and is encased with the bones of the vertebral column. While running downwards the spinal chord gives out many branches of nerves on both the sides which spread all over the body and conduct stimuli towards the spinal chord as well as the impulses from the controlling centres of the brain to the organs and tissues. The nerves that bring the stimuli towards the spinal chord are called the sensory nerves and the nerves that conduct the reactions from the brain and spinal chord to the organs are called the motor nerves.
The autonomous nervous system (ANS) controls the working of the heart, the digestive organs, the excretory organs like kidneys, the endocrinal glands and the other organs of the system. Autonomous nervous system helps in autonomic or subconscious control of the system. This system has two types of nerves called the sympathetic nerves and the parasympathetic nerves. Autonomous nervous system is specially connected to the hypothalamus of the brain and the ductless glands of the endocrinal system. The sympathetic nerves stimulate an organ and the parasympathetic nerves depress it. The sympathetic nerves are concerned with the mobilisation of the latent reserves of the organs when under any stressful situations certain extra efforts are required. The parasympathetic nerves are concerned with the functions pertaining to regeneration of the organs.
The imbalance in the autonomic nervous system results in a situation known as autonomic balance of an individual. This is all about maintaining a balance between all the functions of the autonomous nervous system. This is because if the functions of the two parts are not balanced one would start dominating the other function and it would be very harmful to the system.
Yoga Exercises and Yoga Asanas for Nervous System
The brain is also very prone to situation of chronic degenerative diseases caused mainly due to oxidative stress. So it is very important to understand the devastating damages that these situations can cause to the brain and try to take care to prevent such situations from arising as it is almost next to impossible to cure them with the present available medical treatments. Some of these situations are Alzheimer's dementia, Parkinson's disease and Multiple sclerosis. Prevention is considered to be a better option than cure for all these situations. For more details on oxidative stress please refer the section of Yoga for Lifestyle Disorders.
Yoga is a form of discipline that can help in complete relaxation through the practices of yoga nidra and meditation. In addition, the practice of yoga teaches a practitioner to relax the system voluntarily. This means it gives a multifarious capacity to the practitioner to actually learn to impart rest and recuperation to the entire system. This is important in the present day scenario when the life is generally full of stress and people are normally having a difficult time with their nerves. By relaxing the body not only all the internal organs get deep rest but the nervous system that controls all the internal organs and functioning of all the systems also gets recuperated. This makes yoga the best form of practice to soothe the system in the stressful life of the modern days. There are various yoga asanas or yoga exercises that can help tremendously in controlling all the activities of the nervous system. The yoga asanas or yoga exercises are designed in a very natural way so they do not put any strain on the body but are extremely relaxing.