Nährstoffresorption

Nährstoffresorption refers to the process by which digested nutrients are absorbed from the digestive tract into the bloodstream or lymphatic system. This crucial step in digestion ensures that the body receives the essential building blocks and energy sources it needs to function. The primary site for nutrient absorption is the small intestine, which is highly adapted for this purpose with its large surface area created by folds, villi, and microvilli. Different nutrients are absorbed through various mechanisms, including passive diffusion, facilitated diffusion, and active transport.

Carbohydrates are broken down into simple sugars like glucose, which are absorbed mainly in the small intestine via active transport and facilitated diffusion. Proteins are digested into amino acids, which are also absorbed through active transport mechanisms in the small intestine. Fats are broken down into fatty acids and glycerol. While short-chain fatty acids can be absorbed directly into the bloodstream, longer-chain fatty acids are reassembled into triglycerides, packaged into chylomicrons, and absorbed into the lymphatic system before eventually entering the bloodstream.

Vitamins are absorbed in different parts of the digestive tract. Fat-soluble vitamins (A, D, E, K) are absorbed along with fats in the small intestine, while water-soluble vitamins (B vitamins, vitamin C) are absorbed directly into the bloodstream, often via specific transporters. Minerals, such as iron and calcium, are absorbed in the small intestine through regulated active transport processes. Water and electrolytes are absorbed throughout the digestive tract, with the majority of water absorption occurring in the large intestine. Efficient nutrient resorption is vital for overall health and is influenced by factors like the health of the intestinal lining, the presence of digestive enzymes, and the overall diet.