抽象的

Nutrient digestion and absorption is the complex and specific task of the gastrointestinal system.

Matt Hayatt

The intestinal wall muscles combine food with digestive juices from the pancreas, liver, and intestine and drive the mixture forward for digestion. The small intestine's walls absorb water and digested nutrients into the circulation. Nutritional nutrients, vitamins, minerals, and fluids enter the body through the gastrointestinal system. Proteins, lipids, and complex carbohydrates are broken down into absorbable units (digested) in the small intestine, although not solely. The digestive products, vitamins, minerals, and water pass through the mucosa and into the lymph or bloodstream (absorption). The digestion of big foods is a well-ordered process requiring a large number of digestive enzymes. The salivary glands' enzymes attack carbohydrates (and fats in some species); the stomach's enzymes attack proteins and fats; and the exocrine component of the pancreas’ enzymes destroys carbs, proteins, lipids, DNA, and RNA. The luminal membranes and cytoplasm of the cells that line the small intestine include additional enzymes that finish the digesting process. The hydrochloric acid secreted by the stomach and the bile secreted by the liver help the enzymes work.