Final answer:
Cells in the intestines and kidneys have villi and microvilli to increase surface area for efficient nutrient diffusion. Microvilli are particularly important in the small intestine where they aid nutrient absorption. These adaptations are vital for the body's homeostasis.
Step-by-step explanation:
Cells of the intestines and kidneys are specialized for rapid diffusion of molecules. In these organs, villi and microvilli of the epithelial cells increase the surface area of the membrane through which molecules will pass. These structures facilitate the absorption of nutrients by diffusion, allowing for an efficient transfer of substances into the blood capillaries and subsequently to the liver via the hepatic portal vein.
Specifically, epithelial cells in the small intestine absorb nutrients effectively thanks to the increased surface area provided by the microvilli. Similarly, renal tubule cells in the kidneys have adaptations that maximize the surface area for filtration and reabsorption. Overall, these specializations play a crucial role in maintaining the body's homeostasis by allowing efficient transport and processing of molecules.