The last part of the digestive system of the body is involved in the excretion of the waste matter left from the food. In the colon this waste matter is stored and passed out of the system from time to time in the form of faeces. But the excretory system is not just restricted to this. There exist many other organs in the human body that are engaged the process of excretion.

These organs of the excretory system consist of kidneys, the ureters, the urinary bladder, the urethra and the skin. The kidneys are two in numbers and are situated in the abdominal cavity at the back, one on each side of the spinal chord at the level of twelfth thoracic and the upper three lumbar vertebrae. Each kidney has complicated internal structure. It has an outer layer called the cortex. Its inner layer is called the medulla. Each layer is very richly supplied with blood with numerous arteries, veins and capillaries. The kidneys contain a network of very minute tube like structures called nephrons. These are so numerous that if they are placed end to end they will cover a total distance of about sixty kilometres despite their being microscopic in size.

For the process of excretion to proceed the blood is brought to the kidneys by a large artery. This artery ramifies into numerous arterioles and capillaries which come in contact with the nephrons where the waste matter is separated from the blood. An equally big vein finally collects the deoxygenated blood from the kidneys and takes away for purification. In the nephrons of the kidney the blood is strained and the unwanted materials like the extra amount of water, salts, toxins and other biochemical processes are separated from the blood through this network of tiny tubes. This is the urine, which is then passed out from the kidneys to the ureters and gets stored in the urinary bladder. The urine is passed out from the body through a duct called urethra.

The kidneys mainly filter out the urea and it is converted into ammonia. By this process a balance is maintained between the acid and the alkaline bases in the body. The amount of urine produced in the system depends on factors like liquid intake of the system and amount of sweating happening from the skin. The pigments in the urine help in deciding various diseases of the kidneys, urinary bladder, uterus and liver.

The skin is the other excretory organ. It is also the most expansive organ of the entire system. It covers the entire body and forms the outer covering of the body. The skin has the arrangement of getting rid of excess salts and water from the blood. This is done through a system of intricately arranged minute sweat glands present in the lower layers of the skin. When the blood flows through these sweat glands they separate the salts and water along with some other unwanted toxins from the blood. The separated fluid comes to the surface of the skin in the form of sweat and evaporates. This keeps the body temperature down in the hot summer months. This is the system of the body to keep itself cool and also to release the excessive toxins from the system.

The blood not only provides oxygen to the system but also performs the function of eliminating the carbon dioxide from the system, so it also performs the excretory function.

These days there is a tremendous increase in number of people suffering from kidney disorders. In the last few years the number of people undergoing the kidney replacement surgery has enormously escalated. This is attributed to be another form of chronic degenerative disease. Due to excessive oxidative stress the free radicals attack the excretory system and result in various forms of degenerative kidney orders. There are many cases that are diagnosed at a very later stage and by then any kind of treatment is not possible to be administered. The patient has to undergo the organ replacement surgery. This comes with its own set of ramifications. The body, which already shows severe signs of auto-immune tendencies many-a-times, simply rejects the external organ and the hunt for another donor and another set of surgical procedures comes into force. This has become an every day scenario especially in many developing countries. For details on oxidative stress please see the section of Yoga for Lifestyle disorders.

Yoga Asanas and Yoga Postures for Human Excretory System

The situation is mainly attributed to conditions of improper food habits followed for extensively long periods of time. The excessive consumption of non-vegetarian food by the people is one common reason for this situation to arise. Excessive consumption of animal protein puts an undue pressure on the excretory system. Excessive consumption of alcohol is also another reason. The kidneys have to work overtime to remove the toxins of alcohol from the system. The scientists are trying to find some sort of genetic link to the chronic degenerative diseases. Why some people become more prone to them than the others is a question that is plaguing the scientific community worldwide.

Yoga is the only methodology that can actually help in stimulating the internal organs of the system. Certain yoga asanas and yoga postures should be done regularly so that all the internal organs of the abdominal cavity are adequately exercised and kept in proper working order.