The first stage is ingestion, and it is the process by which food is taken into the body and includes the processes that take place in the mouth like chewing and the saliva creating a chemical reaction to help break down the food for swallowing. The next process is digestion, during which the ingested food is broken down into a form that can be absorbed and assimilated in the cells and tissue of the body.
There are two types of processes that make up the digestion process: the mechanical process, which include chewing or processing food in the mouth, and also the chemical process, meaning the chemical reaction of the enzymes, bile and acids to break down the food. Absorption occurs, which is the uptake of fluids and nutrients into the tissue of the body. Digested food is absorbed into the blood and lymph by way of the alimentary canal. Most of the absorption process takes place in the jejunum and ileum of the small intestine. Alcohol, on the other hand, is readily absorbed by the stomach.
The small intestine is lined with finger-like processes called Villi, which increase the surface area allowing the most and best absorption rate. Lastly is the elimination process, which is getting rid of any waste products from the blood via the kidneys and urinary tract.