Final answer:
At rest, blood flow is greatest in the GI tract and liver, as these organs are actively engaged in digestive processes and nutrient metabolism, even when the body is not in motion.
Step-by-step explanation:
The question is asking about the distribution of blood flow in the body at rest. It is important to understand that blood flow is regulated based on the body's needs, which are controlled by nerve and hormone signals. During rest, certain organs like the brain and liver receive a constant or significant blood supply. The blood flow to the brain is kept largely consistent regardless of activity levels to ensure its high-priority functions are maintained. After eating, the GI tract receives more blood due to vasodilation in that area. Considering these factors, at rest, blood flow is greatest in the GI tract and liver, which are actively engaged in processing nutrients from the food we consume.
Conversely, during periods of exercise or increased body temperature, the body redistributes blood flow to the skeletal muscles, heart, and skin (integument) to facilitate increased activity and heat dissipation. Organs like the kidneys and some digestive organs receive less blood due to vasoconstriction.