Briefly describe the digestion of food materials in alimentary canal with the help of diagram
A.
- The alimentary canal is basically a long tube extending from the mouth to the anus.
- Food is masticated by our teeth in the mouth and mixed with saliva to make it slippery and wet.
- Salivary glands secrete saliva which contains amylase that helps in the breakdown of carbohydrates into simple ones.
- The soft food mixed with saliva passes through oesophagus or food pipe by wave like movements called peristaltic movements to the stomach.
- The gastric glands in the stomach secrete gastric juice that Contains hydrochloric acid, protein digesting enzyme pepsin and mucus.
- Bile juice secreted by liver and pancreatic juice secreted by pancreas release into the duodenum of small intestine.
- 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.
- Complete digestion of carbohydrates, fats and proteins takes place in the small intestine by intestinal juice.
- Finger-like projections present in the walls of small intestine are called villi. They absorb the digested food into the blood.
- Rest of the food is sent into the large intestine where most of the water present in it is absorbed from the food.
- This material is then expelled through the anus which is the last part of the alimentary canal.