Ingested dietary substances must cross cell membranes to be used by the body is called

The correct answer is: Absorption.

Explanation:

Absorption can be defined as the process by which nutrients obtained by the digestion of food in the stomach and the small intestine is taken up by the walls of the small intestine for the purpose of distribution throughout the body.The inner mucosal lining of the small intestine is made up of numerous finger-like tissue projections called Villi.The Villi is made up of simple columnar epithelial cells which is further comprised of fine finger-like projections called the Micro-villi.These structures help in increasing the surface area of the small intestine which in turn promotes increased absorption of nutrients.Each of the vilus has a network of capillaries and lymphatic vessels (lacteal duct) located in close contact beneath it.These epithelial cells conducts simple digested nutrients like amino acids, sugars, etc form the intestinal lumen into the capillaries and lipids and fatty acids from the intestinal lumen into the lacteal duct.These nutrients are then transported to all the parts of the body through the blood.