Digestive System of Humans
In the previous section, we learned that food taken in through the mouth is grinded mechanically with teeth and mixed with saliva and passed to the stomach through the esophagus. The food is then mixed with other digestive enzymes and on completion of digestive process; the food is next passed on to the small intestine.
The small intestine:
The small intestine is thin, 7.5 meters long and is coiled and sits within the large intestine. The liver and pancreas found below the stomach develop their own digestive juices and pour it in the small intestine. The liver is a brown gland located on the right side of the abdomen region. The liver is the largest gland of our body and produces a yellow-colored digestive fluid called bile. The bile is stored in a sac called gall bladder. The bile salts help in the digestion of fats present in the food. The liver also plays a significant role in the detoxification of the food products. The pancreas is a long, cream-colored organ which consists of specialized cells producing insulin and glucagon to break down the carbohydrates and proteins present in the food.
The bile is stored in a sac called gall bladder. The bile salts help in the digestion of fats present in the food. The liver also plays a significant role in the detoxification of the food products. The pancreas is a long, cream-colored organ which consists of specialized cells producing insulin and glucagon to break down the carbohydrates and proteins present in the food.
The partly digested food from the stomach that enters into the small intestine gets completely digested with the help of digestive enzymes and breaks down the carbohydrates and other starch products into glucose, fats into fatty acids and glycerol and proteins into simpler amino acids.
These simpler substances can be easily used in the energy-making processes of our body. These simpler substances are absorbed by the blood vessels present on the wall of the small intestine and circulated in the blood, thus transporting it to different organs of the body. Moreover, the walls of intestine consist of many finger-like structures called as villi (singular – villus). Each villus has their network of blood vessels around them, which help in transporting the nutrients. These villi are responsible for increasing the surface area of the intestine, so as to increase the rate of absorption.
The nutrients transported to other organs of the body assimilate these nutrients and produce other complex proteins, carbohydrate, and fats required for the maintenance of the body. This process is called as assimilation.
The large intestine is wider and 1.5 meters long. The main function of the large intestine is to extract water and salts from the remaining waste and pass on the wastes to the rectum and then to the anus, from where it is excreted out of the body. This excretion process is also called as egestion.
Thus, we have learned that the food we eat in broken down into simpler substances and transported to various organs of the body so as to utilize it in different manners, such as producing energy, producing different proteins required for the growth and repair of the body.