Nutrition in Human Beings

Alimentary canal is a long tube extending from the mouth to anus.

In mouth there is an enzyme which is called salivary amylase and it is present in saliva, Its work is to break starch to simple sugar

Then food is moved to food pipe which is called Oesophagus. Here food is moved by process of peristaltic movement. to push food forward.

Then the food is moved to stomach, In stomach HCl,Pepsin and Mucus are present, First HCL makes the medium(food) acidic which facilates the functioning of pepsin.As we know that pepsin work effectively in acidic medium. Then, Pepsin breaks the protein to Amino-Acids. The mucus protects the inner lining of stomach from HCL under normal condition.

Then food is moved to small intestine where gall bladder which is stored in liver secrets bile juice and bile salts. Bile juice makes the medium basic to help trypsin and other enzyme.Then, Bile salt large fat globules to smaller one. Then Pancriatic glands secrets Trypsin and lipase. The workin of trypsin is to break protein into amino acids.and working of lipase is to break fats to fatty acids.
The Small intestine has finger-like projection caled villi which increase the surface area for absorption of food.These finger like projection are richly connected to blood vessels.The small intestine is also called Site of .
intestinal juices in small intestine breaks left protein,Fats,Carbohydrates to Amino acid, Fatty acids and glucose respectively.

Then food is moved to large intestine where maximum water is absorbed.

And then the waste product removed from anal, here the rmoval of waste is regulated by anal sphinchter