Process of Absorption

Absorption is the process by which the digested food is passed into the blood vessels in the wall of the intestine. The process of absorption is essential for the body as it allows the nutrients to enter the bloodstream and be transported to the various parts of the body. The absorption of nutrients takes place in the small intestine.

Mechanism of Absorption

The absorption of nutrients takes place in the small intestine, which has a large surface area for absorption due to the presence of villi and microvilli. The following are the steps involved in the process of absorption:

1. Diffusion: The nutrients that are small and lipid-soluble, such as fatty acids, glycerol, and some vitamins (A, D, E, and K), are absorbed by diffusion through the cell membrane of the villi.

2. Facilitated Diffusion: Glucose and amino acids are absorbed by facilitated diffusion through the cell membrane with the help of carrier proteins.

3. Active Transport: Some nutrients such as sodium, potassium, and calcium are absorbed by active transport through the cell membrane with the help of carrier proteins.

4. Endocytosis: The large molecules such as lipids and proteins are absorbed by endocytosis. The cells of the intestinal wall engulf the nutrients by forming vesicles around them and then transport them into the bloodstream.

Conclusion

In conclusion, absorption is the process by which the nutrients are passed into the bloodstream from the intestine. The process of absorption involves diffusion, facilitated diffusion, active transport, and endocytosis. The absorption of nutrients is essential for the proper functioning of the body, and any impairment in the absorption process can lead to malnutrition.