Question

Discuss the digestion of food in the small intestine.

Answer 1

Digestion:

• Digestion is the process of converting large food particles into a simple form that the body can absorb.
• It is a multistep process that involves various organs and glands.
• The process of digestion in humans begins in the oral cavity. The food from the oral cavity enters the stomach through a food pipe where partial food digestion occurs.
• The partially digested food enters the small intestine from the stomach for complete digestion and absorption.

Digestion in the small intestine

• The small intestine is a long tube that is divided into three segments; duodenum, jejunum and ileum.
• The food that enters the small intestine is acidic in nature which is converted to alkaline by the release of bicarbonate ions.
• Bicarbonate ions are released by the pancreas as a component of pancreatic juice along with other pancreatic enzymes like trypsin, chymotrypsin, pancreatic amylase, and lipases.
• In the small intestine, trypsin and chymotrypsin are the protein-digesting enzymes that break down proteins into amino acids.
• Pancreatic amylase acts on carbohydrates and digests to release glucose and other small sugar units.
• Lipases act on fats and degrade them into small fatty acids and glycerol.
• Bile juice formed by the liver and stored by the gallbladder is also released into the small intestine, which causes the emulsification of fats.
• The small intestine wall absorbs the simple forms of complex nutrient molecules like amino acids, glucose, and fatty acids.