Digestion is the process of breaking down and distributing food throughout the body. The digestive system comprises of the mouth and teeth at one end and the anus at the other. Between these two extreme ends, a long tube like structure with different names and different functions process the food materials into a usable form. One among them, the esophagus passes through the chest and joins the mouth to the stomach. The stomach extends to the small intestine or small bowel, which is a narrow long tube through which most of the food absorption into the bloodstream takes place.
Let's start our study with our mouth, which is the starting point of the process of digestion. It's there that the mechanical breaking down of food takes place due to chewing and the release of saliva from the salivary glands, whose ducts enter the mouth. The importance of chewing is normally ignored by the general public is merely taken for granted. Nevertheless, proper digestion necessitates extensive chewing, so that food is converted in to a liquid form before it is swallowed. Without proper chewing, undigested food particles may find a place in the stool. The presence of enzymes in the saliva helps to break down complex carbohydrates into simple sugars. Therefore, it is always advisable to chew your foods well, as this will lead to healthier teeth and gums and better digestion.
Some of the vital parts of the lower digestive system consist of the pancreas, the small intestine and the large intestine. The appendix, the rectum, and the anus are positioned below these organs. All of the lower digestive organs play a part in processing food. In the absence of lower digestive organs, the human body would not be able to receive the required nutrients. Chemical digestion and the wave like movement, called peristalsis, occur in the lower digestive system.
It is these lower digestive organs that mix nutrients with digestive juices such as pancreatic and intestinal juices and take in the nutrients from the food. The pancreas supplies pancreatic juices and is then passed into the small intestine. The walls of the small intestine produce intestinal juices. Digestive juices constitute of enzymes that allow the process of digestion to speed up. The foods we eat are mainly made up of fats, carbohydrates, and proteins, in which enzymes break down to simpler parts. The fats are reconstituted to glycerol and fatty acids. The carbohydrates, which are also known as sugars and starches, are broken down into simple sugars while the proteins are broken down into amino acids. After this, all these particles are taken or absorbed into the bloodstream. During the process of digestion of amino acids, they are separated and get absorbed into the body cells. These separated amino acids are put into use for building body proteins.
Certain things like water, vitamins, and minerals need not to be digested, only absorbed. At the end of the process, the remaining food substances are converted into feces. The process that involves the feces occurs in the large intestine, the rectum, and the anus. The appendix is placed in the same area as the large intestine, the rectum, and the anus. The pancreas, without doubt, is an essential organ in the human body. It's a gland that is approximately five to six inches long and is located behind the stomach. The pancreas creates important digestive juices composed of enzymes, which breakdown fats, proteins, acids, carbohydrates, and bicarbonates.
The pancreas is encircled by blood vessels that pump out the hormones glucogen and insulin into the blood. These glucagons make glycogen to change into glucose at a high rate. Another pancreatic hormone, insulin helps glucose to enter into the body cells. It also controls the blood sugar and avoids it from building up. If the pancreas could not turn out the insulin, then the result is diabetes, a sugar build up.
Another essential organ, the small intestine absorbs nutrients from foods and sends them into the blood stream. The small intestine can be further divided into three sections; the duodenum, jejunum, and ileum. It is at duodenum that, partially digested food and chemicals directly enter from the stomach. The section jejunum absorbs nutrients into the blood stream. At ileum, the left over nutrients are absorbed into the blood stream. The small intestine is 18-23 feet long in the average adult and is in the shape of a long coiled looped tube. A type of movement that occurs in the small intestine called peristalsis moves food slowly through the small intestine. These wavelike movements occur once in a while thus, allowing nutrients to be absorbed.
The large intestine, named also as colon, takes control of the food, the water and the fiber that the small intestine is unable to break down. After that, bacteria convert the waste into feces. During this time, vitamins B and K are formed for the body. The feces then proceed through the digestive system towards the anal canal. The rectum gathers and holds the feces until it is ready to be expelled by the body.