Final answer:
The small intestine, with its villi and microvilli, increases surface area to enhance nutrient absorption, which is then transported via the bloodstream to the liver.
Step-by-step explanation:
The structure of the small intestine and its fingerlike projections called villi greatly enhance digestion and absorption. The small intestine, with its long tube-like form, is intricately folded and covered in villi to increase the surface area for nutrient absorption. Each villus is further covered by microscopic projections known as microvilli. The increased surface area provided by the villi and microvilli facilitates efficient absorption of nutrients from processed food into the bloodstream. This anatomical adaptation is essential for maximizing the transfer of nutrients into the hepatic portal vein, which then carries these nutrients to the liver for distribution or detoxification.