Gastrointestinal System

Gastrointestinal system is concerned with the digestion and absorption of foods we eat. it is consist of the alimentary canal known as the digestive track or the gut, extending from the mouth to gut and the related organs.

The alimentary canal is made up of smooth muscles which contracts and move the food in waves along the track. this process is known as peristalsis. food is broken down into smaller absorbable forms by a group of protein substances known as enzymes present in the digestive juices, secreted by the exocrine glands of the alimentary canal.

Enzymes are complex proteins that are capable of bringing chemical changes in other substances without being changed themselves. they are capable of accelerating the speed of chemical reactions.

the function of alimentary tract is to breakdown food into smaller particles, absorb the nutrients and expel the rest as wast. different pats of the tract has different functions.

Food enters through the mouth or oral cavity. Jaws, teeth and tongue work to mash the food and mix the food into smaller particles. saliva secreted from the salivary glands moistens the food to make it easier to transport. saliva also contains enzymes that begin the process of digestion hence, the process of digestion begins in the mouth.

from the mouth food enters the esophagus and than to the stomach. Stomach is acidic in nature which is necessary for proper functioning of the enzymes in the stomach. this also helps to destroy any micro organisms which might enter with the food. in the stomach the food id further broken down into smaller particles and mixed with digestive juices to form a semi solid mixture. this mixture passes in to the duodenum which is the first part of the small intestine. More digestive juices are added to this mixture and the process of digestion continues.

As the food particles move further down the small intestine they are reduces into smaller and smaller constituents of, carbohydrates, proteins, fats and water. these are absorbed through the lining of the small intestine and pass into the blood stream. They are either stored in the liver to be used later or carried to places where they are metabolized to get energy or for building and repair.

two other organs are essential in the process of digestion.One is the liver which store nutrients and and also produces bile. Bile helps in the digestion and absorption of fats and fat soluble vitamins. Bile travels into the small intestine via the gall bladder and the bile ducts.

the other organ is the pancreas which makes several enzymes involved in the breaking down of food in the small intestine.

Once the food reaches the end of the small intestine, what's left is essentially wast material. The wastes enters the large intestine or colon. As it travels along the colon, water is re-absorbed and the waste hardens and becomes feces. the fecal matter is than stored in the rectum, before being expelled through the anus.