The Process of Digestion and Nutrient Absorption

In this section, we will delve deeper into the processes of digestion and nutrient absorption, which involve both mechanical and chemical breakdown of food, as well as the transfer of nutrients into the bloodstream.

Mechanical and Chemical Digestion

Mechanical digestion refers to the physical breakdown of food into smaller pieces, while chemical digestion involves breaking down complex molecules into simpler ones using enzymes and other chemicals. Both types of digestion work together to ensure that the body can efficiently absorb nutrients.

Mechanical Digestion:

Chewing in the mouth
Mixing and churning in the stomach
Segmentation in the small intestine

Chemical Digestion:

Salivary amylase in the mouth
Gastric juice in the stomach
Pancreatic enzymes and bile in the small intestine

Absorption of Nutrients

The small intestine is the primary site for nutrient absorption. The lining of the small intestine contains finger-like projections called villi and even smaller projections called microvilli, which increase the surface area and facilitate nutrient absorption. The capillaries within the villi absorb nutrients and transport them into the bloodstream.

Absorption of carbohydrates: Carbohydrates are broken down into simple sugars, such as glucose, which are absorbed by the small intestine and transported to the liver.
Absorption of proteins: Proteins are broken down into amino acids, which are absorbed by the small intestine and transported to the liver.
Absorption of fats: Fats are broken down into fatty acids and glycerol, which are absorbed by the small intestine and transported to the liver via the lymphatic system.

Elimination of Waste

After the process of digestion and absorption is complete, the remaining indigestible food matter and other waste products move into the large intestine. The large intestine absorbs water and electrolytes, forming feces, which are stored in the rectum until they are eliminated from the body through the anus during defecation.

Summary

The processes of digestion and nutrient absorption are essential for maintaining homeostasis and overall health. By understanding these processes, we can appreciate the intricate balance our bodies maintain to ensure we receive the nutrients we need for growth, repair, and energy production.

Page updated

Google Sites

Report abuse