Final answer:
The smallest particles of food are absorbed into the bloodstream through the small intestine, providing nutrients to the body's cells. Substances that cannot be absorbed are eliminated as waste through the large intestine.
Step-by-step explanation:
When the smallest particles of food are broken down, they undergo a process known as absorption. This critical step occurs primarily in the small intestine, where most nutrients are absorbed from the lumen of the alimentary canal into the bloodstream through the epithelial cells of the mucosa. Lipids, one type of nutrient, are absorbed through lacteals and are then transported through the lymphatic vessels to the bloodstream. Nutrients absorbed in this manner are essential for cells throughout the body to carry out various functions.
Substances in food that cannot be digested and absorbed are then moved to the large intestine and eventually eliminated from the body as solid waste, in a process called elimination. This procedure is essential to discard the undigested food contents and is an integral part of the digestive process. The large intestine plays a crucial role, absorbing any leftover vitamins, salts, and water before ultimately forming feces.