Most of the body disorders are mainly concerned with the malfunctioning of the digestive system. In short we can say that our digestive system has a d...
Most of the body disorders are mainly concerned with the malfunctioning of the digestive system. In short we can say that our digestive system has a direct influence in our daily life. More over when you experience any digestive trouble, you get easily frustrated. A healthy digestive system helps to keep one optimistic and cheerful in his life. That is why doctors emphasize the need of a healthy digestive system. You will find valuable information about the process of digestion in this article.
How our digestive system functions
The food which we consume cannot be directly absorbed by the body. First it is converted into substances which can be easily entered into our blood stream. This process is known as digestion. The digestion starts right from the time when it enters into the mouth. Mouth helps in breaking down the food particles while chewing and also secretes saliva which is essential for digestion. The amount of saliva produced depends on the taste and nature of the food, as well as on the appetite.
Ptyalin, an enzyme present in saliva helps to break down the starches present in the food into simpler forms of carbohydrates. Saliva also includes bicarbonate which helps to neutralize the acids present in the stomach. Experts suggest that slow eating and adequate chewing are important for the saliva to carry out its function. After the food has been chewed thoroughly, it passes through the esophagus (food pipe). From here it is moved to the stomach by a series of rhythmic waves called peristalsis. Cardiac sphincter which lies in the entrance to the stomach allows the food to enter into the stomach.
Our stomach when being empty is about the size of our hand held palm to palm. The walls of our stomach are much thicker when compared to other parts of the digestive tract. The stomach churns and squeezes the food with the help of gastric juices secreted by the millions of glands present in the stomach walls. The gastric juices produced by the glands are comprised of enzymes named pepsin and hydrochloric acid which are in charge of breaking up of proteins. Another enzyme named rennin is secreted in small quantity which in turn curdles certain type of foods so that they can be exposed to the longer time of action to the gastric juices. Pepsinogen, another enzyme present in the gastric juice helps to terminate the action of saliva. Pepsinogen when combined with hydrochloric acid helps to destroy the germs present in the food.
The amount of gastric juice secreted is directly proportional to the amount of food consumed and also the appetite of the person. Food items which are tasty and aromatic tend to secrete abundant gastric juices whereas tasteless and monotonous foods are not.
An average meal requires about 800cc of gastric juices for digestion. Out of this 800 cc, only 200 cc will be secreted during eating and the rest will be secreted after when the food remains in the stomach. The duration of solid food remaining in the stomach varies from two to six hours depending on the nature of the food. Water and liquid food items do not remain in the stomach for more than a few minutes. It moves immediately into the small intestine and is absorbed by the blood stream.
From the stomach the food moves on to the small intestine through a valve called pyloric valve. The food is now in a semi-solid stage called chyme. The food moves into the duodenum, the initial part of the small intestine get mixed up with digestive juices produced by various glands. Out of these glands, pancreas is the most important one. Pancreas secretes enzymes such as amylase, lipase and trypsin which have the potential to digest all types of food items such as proteins, fats and carbohydrates. Pancreas will function properly only when the food from the stomach is properly get mixed with hydrochloric acid. Normally 600 cc of pancreatic juices are used by our body everyday.
Liver, the biggest individual gland in the body is another important gland in the digestive system. Liver stores the food after it has been absorbed by the flood. It stores the food in the form of glycogen. Whenever the body is in need of energy, the glycogen is converted into glucose and discharged into blood stream. It also supports the lipase (pancreatic juice) in breaking down the fats. The small intestine walls are similar to velvet which contains thousands and thousands of hair like nodules called villi which contains tiny blood vessels. They help in the absorption of nutrients in the chyme to the blood vessels.
The chyme travels through small intestine and passes into large intestine through a valve called ileocecal valve. This valve helps in regulating the too much entry of chyme into the large intestine at a time as this may result in the emptying of small intestine too quickly. By the same time it also monitors and regulates the chyme from going back to small intestine.
By the time of entering the large intestine, chyme contains mainly of waste products and water. The water will be absorbed by the large intestine in order to avoid dehydration. The waste alone will be transferred to the rectum where it is eliminated from the body I the form of stool.
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