The Small Intestine

The small intestine is a long, coiled part of the digestive system where most of the digestion and absorption of food take place. It is about 6 meters long (20 feet). It connects the stomach to the large intestine. It is divided into three sections:

• Duodenum: The first part
• Jejunum: The middle part
• Ileum: The last part

1. Digestion of Food: Food mixes with three digestive juices.

• Bile (from the liver): breaks down fats.
• Pancreatic juice (from the pancreas): Digests proteins, fats, and carbohydrates.
• Intestinal juice (from intestine walls): Completes digestion.

2. Absorption of Nutrients:

• Glucose, amino acids, fatty acids, and vitamins are absorbed into the bloodstream.
• Villi (tiny finger-like structures) increase surface area for better absorption.
• Blood vessels in villi transport nutrients throughout the body.

3. Movement of Food: Peristalsis (wave-like movements) pushes food forward through the small intestine. The small intestine ensures complete digestion and absorption of essential nutrients to nourish the body.