Small Intestine

The small intestine is a long, coiled tube located in the lower part of the digestive system. It plays a crucial role in the digestion and absorption of nutrients from the food we eat. The small intestine is divided into three main parts: the duodenum, the jejunum, and the ileum.

Structure of the Small Intestine

The inner lining of the small intestine contains millions of tiny finger-like projections called villi. These villi greatly increase the surface area of the small intestine, allowing for efficient absorption of nutrients. Each villus contains blood vessels and lymphatic vessels that transport nutrients to the rest of the body.

Function of the Small Intestine

The small intestine is where the majority of digestion and nutrient absorption takes place. It receives partially digested food from the stomach and continues the process of breaking down carbohydrates, proteins, and fats with the help of enzymes produced by the pancreas and the small intestine itself.

Study Guide

1. What are the three main parts of the small intestine? Answer: The duodenum, the jejunum, and the ileum.
2. What is the function of the villi in the small intestine? Answer: Villi increase the surface area of the small intestine for efficient absorption of nutrients.
3. Which organs produce enzymes that aid in the digestion of food in the small intestine? Answer: The pancreas and the small intestine produce enzymes for digestion.
4. What is the role of the small intestine in the digestive system? Answer: The small intestine is where the majority of digestion and nutrient absorption takes place.

Understanding the structure and function of the small intestine is important for grasping the complexities of the digestive system and how our bodies extract nutrients from the food we consume.