Nutritional absorption of food by the human body can be simply summarized in five stages: chewing, digestion by gastric juice, absorption in the small intestine, entry into the bloodstream, and delivery to individual cells.
Food is first chewed and crushed into small pieces by the human mouth, and then enters the stomach through the esophagus, where it is fully stirred and mixed, and the stomach contains many kinds of gastric juices and digestive enzymes, which will further break down the food, and then reaches the small intestine.
The small intestine is the main place responsible for nutrient absorption in the human body, absorbing amino acids, glucose, proteins, fatty acids, vitamins, minerals and other nutrients from the food to the hundreds of thousands of villi on the wall of the small intestine, the villi of the small intestine will transfer the nutrients to the bloodstream, and through the body’s blood circulation to the various tissues and cells, the nutrients are ultimately absorbed by the cells of the human body.