Briefly describe the digestion of food materials in alimentary canal with the help of a diagram.

Explanation

1) The alimentary canal is basically a long tube extending from the mouth to the anus.
2) Food is masticated by our teeth in the mouth and mixed with saliva to make it slippery and wet.
3) Salivary glands secrete saliva which contains amylase that helps in the breakdown of carbohydrates into simple ones.
4) The soft food mixed with saliva passes through oesophagus or food pipe by wave like movements called peristaltic movements to the . stomach.
5) The gastric glands in the stomach secrete gastric juice that contains hydrochloric acid, protein digesting enzyme pepsin and mucus.

6) Bile juice secreted by liver and pancreatic juice secreted by pancreas release into the duodenum of small intestine.
7) Emulsification of fats is done by bile juice. Pancreatic juice contains enzyme trypsin for carrying on the process of digestion of proteins and lipase for fats .
8) Complete digestion of carbohydrates, fats and proteins takes place in the small intestine by intestinal juice.
9) Finger-like projections present in the walls of small intestine are called villi. They absorb the digested food into the blood.
10) Rest of the food is sent into the large intestine where most of the water present in it is absorbed from the food.
11) This material is then expelled through the anus which is the last part of the alimentary canal.