The digestive system begins from the mouth. Then is the pharynx, the gullet or the food pipe, the stomach, the duodenum, the small intestine, the large intestines, the colon and the anus. The food pipe, the stomach, the duodenum, the small intestine, the large intestine and colon are collectively called the alimentary canal. The mouth receives the food and it is bit into small pieces, moistened with the saliva and chewed here with the help of the teeth so that it can pass down the throat easily. The pharynx is a junction where paths from the nose, going down to the lungs, the mouth and the ears meet. The food passes through the pharynx and goes into the stomach.
The food remains in the stomach for about two hours and gets mixed with the hydrochloric acid and digestive juices secreted from the stomach walls. It then passes to the duodenum and gets mixed with three digestive juices namely the pancreatic juice, the bile juice produced in the liver and the juice of the duodenum. The result of the activity of these juices is that the constituents of the food like carbohydrates, proteins and fats get broken down to simpler forms so that they can get absorbed into the system easily.
The small intestines are over twenty feet in length and are responsible for absorption of the digested food. The digested food stays in the small intestine for about three hours. When most of the good part is absorbed and assimilated into the system the balance is passed on to the large intestine. The large intestine is about five feet long and here some water is absorbed from the remainder of the food and the rest is passed to the colon to be passed out of the anus in the form of faeces. The absorbed food is mainly stored in the liver and is supplied towards the growth and development of the body via the blood as and when required.
The main food constituents are carbohydrates, proteins, fats, mineral salts and vitamins. The diet should be planned in such a way that all the constituents are in a balance. Carbohydrates, proteins and fats supply the necessary energy to the system. The proteins also help in building of the muscles of the body. The effort to have everything in balance is the key to good health. The main reason for the chronic degenerative diseases to have attacked our generation is the gross imbalance in diet that has crept into our lifestyles. See the section of Lifestyle Disorders for more details. The digestive system suffers from many common ailments from time to time. Most of these as believed by the practices of Ayurveda and yoga are due to improper food habits and excessive stress in the social, emotional and work related situations.
Some of the common ailments of the digestive system are:
Constipation: This is a situation when the person is unable to pass the stool despite feeling the pressure to pass the stool. This is because the water absorption in the large intestine is generally more than the usual and the faeces become excessively dry. This may also be due to irregular bowel habits and also because the person may be in a habit of suppressing the urge to defecate as and when it occurs. More than the physical reasons, emotional reasons are attributed to this condition. It can be a very painful condition for most people who suffer from it. Most of the people suffer from constipation at one point in time or the other but the chronic cases invariably have this problem almost on a daily basis. If excessive pressure is exerted to pass the stool the thin and delicate walls of the anus may rupture and bleeding may occur. This may lead to inflammation of the area and the whole situation may worsen still. The condition of piles is also an offshoot of chronic constipation. Generally giving an enema is the process that gives immediate relief. Yoga recommends Yoga asanas or yoga exercises and processes like Dhauti, Nauli, Basti, Makarasana, and Utkatasana for relieving this situation.
Acidity: This is a situation when the gastric juices produce excessive acidity in the system and it has to be counteracted with taking some medications that can nullify the acids. This situation produces a feeling of deep burning sensation in the alimentary canal especially in the throat and stomach. The people who are prone to acidity should keep away from eating spicy foods and do certain yogic asanas to avoid the situation as far as possible. Severe cases of acidity can develop in ulcers of the alimentary canal and situation of colitis.
Loose Motions: This is a situation where due to improper digestion and absorption the faecal matter is left with excessive moisture and the stool passed is loose in consistency. In severe cases of diarrhoea the stool may be excessively watery. The frequency of passing the stool also increases considerably. In severe cases the body may loose enough moisture and a relentless condition of dehydration may happen, which can be fatal. This situation can happen due to some infection or excessive imbalance in the constitution of the food.
Yoga is a form of discipline that keeps the digestive system completely in order. The practice of yoga asanas or yoga exercises listed hereby can give a person the capacity to develop good digestion and enjoy great health.