what in the digestive system assimilates dissolved food?
I am uncertain of your usage of assimilate.
the vast amount of breakdown of food in to amino acids and simple sugars is done in the small intestine, but all conversion of food to energy is done in cells.
http://en.wikipedia.org/wiki/Small_intestine
In the digestive system, the small intestine is primarily responsible for assimilating dissolved food. It absorbs nutrients from the partially digested food that enters from the stomach. The process of assimilation occurs in the small intestine's inner lining, which is lined with millions of microscopic finger-like projections called villi.
To understand how the small intestine assimilates dissolved food, we need to break down the steps involved:
1. Digestion: The process starts in the mouth, where food is mechanically broken down by chewing and mixed with saliva containing digestive enzymes. The food then travels down the esophagus and enters the stomach where it mixes with acid and digestive enzymes. In the stomach, food is further broken down into a semi-liquid mixture called chyme.
2. Absorption: Once the chyme leaves the stomach, it enters the small intestine. Here, the process of assimilation takes place. The inner lining of the small intestine is highly specialized for absorption. The villi, along with the microvilli on their surface, increase the surface area available for absorption.
3. Nutrient Extraction: As the chyme moves through the small intestine, the villi and microvilli absorb nutrients. These nutrients include carbohydrates, proteins, fats, vitamins, and minerals. They are transported through the villi and into blood vessels or lymphatic vessels called lacteals.
4. Transport: The absorbed nutrients, now in the bloodstream or lymphatic system, are circulated throughout the body to be used as fuel for cellular activities or stored for later use.
In summary, the assimilation of dissolved food occurs in the small intestine, where the inner lining has specialized structures called villi that are responsible for absorbing nutrients from the chyme.