Final answer:
The word root for small intestine, where food enters the blood stream, is 4.6 m (15 ft). The small intestine is a long tube-like organ responsible for completing digestion and absorbing nutrients from digested food. Its highly folded surface with villi and microvilli increases absorption efficiency.
Step-by-step explanation:
The word root for small intestine, where food enters the blood stream, is 4.6 m (15 ft).
The small intestine is a long tube-like organ that is part of the gastrointestinal tract. It is responsible for completing the digestion of protein, fats, and carbohydrates, as well as absorbing nutrients from the digested food and releasing them into the bloodstream.
The surface of the small intestine is highly folded, containing finger-like projections called villi, which increase the surface area for absorption. The villi have microscopic projections called microvilli, which further increase absorption efficiency. Overall, the small intestine plays a crucial role in nutrient absorption and is approximately 4.6 meters long.