Write a detailed note on human digestive system. Explain the importance of enzymes used in digestive system.

Digestive system is a system of organs where many organs and gland work together to digest the food that we eat and discard the waste. The digestive system works from ingestion of food to being digested and absorbed by the body to defecation of waste. The process of digestion is as follows- The mouth receives food and begins mechanical digestion by breaking down the food. The food mixed with saliva, known as bolus, passes down through the pharynx to esophagus via peristalsis. The partially digested food enters the stomach from esophagus. Further digestion occurs in the stomach where the bolus is churned and mixed with the gastric juices. Chemical digestion takes place in small intestine which secretes chemicals that break down the food and take away nutrients to blood stream. The undigested food is passed to the large intestine where maximum water is reclaimed before egestion of solid faeces.

The digestive enzymes assist in digestion and absorption of nutrients in the small intestine. In the process of digestion, the salivary gland produces saliva in the mouth which digests the starch in food to make food soluble and smooth. Pancreas secrete insulin, glucagon and pancreatic juice. The pancreatic enzymes help in digestion of protein, fat and carbohydrates present in the food.Liver produces bile salts which breakdown lipids to fatty acids.