In the small intestine the food is mixed with bile and other digestive juices then digestion is complete.

Digestion is completed in the Small Intestine

The process of digestion begins in the mouth, where food is broken down into smaller pieces through chewing and mixing with saliva. From the mouth, the food travels through the esophagus, also known as the food pipe, and enters the stomach. However, digestion is not completed in the stomach, as it primarily functions to break down food mechanically and chemically through the action of stomach acid and enzymes.

The Small Intestine: The Primary Site of Digestion

The small intestine is the primary site of digestion and absorption of nutrients in the digestive system. It is a long, tube-like organ that is divided into three parts: the duodenum, the jejunum, and the ileum. The small intestine is lined with finger-like projections called villi, which greatly increase the surface area for absorption.

Mechanical and Chemical Digestion in the Small Intestine

Mechanical digestion in the small intestine occurs through the mixing and churning of food by the muscles in the intestinal wall. This helps to further break down the food into smaller particles.

Chemical digestion in the small intestine is facilitated by various enzymes produced by the pancreas and secreted into the small intestine. These enzymes include amylase, which breaks down carbohydrates into sugars, lipase, which breaks down fats into fatty acids and glycerol, and proteases, which break down proteins into amino acids.

Final Steps of Digestion and Absorption of Nutrients

As the food particles are broken down into smaller molecules, they are absorbed into the bloodstream through the villi in the small intestine. The nutrients, such as glucose, amino acids, and fatty acids, are then transported to the liver for further processing and distribution to the rest of the body.

Role of the Large Intestine

While digestion is primarily completed in the small intestine, the large intestine, which includes the colon and the rectum, plays a role in the absorption of water and electrolytes, as well as the formation and elimination of feces.

In conclusion, digestion is completed in the small intestine, where the mechanical and chemical breakdown of food occurs and nutrients are absorbed into the bloodstream. The large intestine primarily functions in the absorption of water and electrolytes.