1. How the food changes consistency and form
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The food changes consistency and form throughout its journey in the gastrointestinal tract of the body. From its original structure, food is subjected to chewing and hydrolysis in the mouth. It becomes a bolus, a ball-like mixture of digested food, and can then be swallowed and passed to the esophagus. The bolus passes through the esophagus, which propels it to the stomach. This ball of digested food goes through churning and hydrolysis in the stomach so that it can melt and become a chyme, a fluid that can be passed into the intestines. Nutrients are absorbed in the small and large intestine before the wastes move into the rectum, then the anus from which the wastes are expelled.
2. How the body was able to absorb the nutrients from the foods we eat
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The food is continuously broken down as it goes through the digestive system. Most of the nutrients are absorbed in the small intestine. Nutrients cross through the walls of the small intestine and enter the bloodstream via passive diffusion and active transport absorption. The blood delivers the nutrients to the rest of the body. The large intestine absorbs water, ions, vitamin K, and such but is not a high yield site for nutrient acquisition.