burpee

I need some help in understanding what happens to food/nutrients directly at the end-point of digestion. I have reviewed how food is transported through the intestines. I understand how the intestinal walls react with nutrients ans continue to pass indigestible or less digestible mass along to the colon.

What I can't seem to "see" in any anatomy of the body is how the nutrient rich material collected in the intestines is transported in the circulatory system.

What are the names of the tissues/organs that collect and transport the intestinal blood supply to the liver? I mean what is the physical method of moving nutrient rich blood in and around? the intestines into major transporting structures?

How do nutrients signal the pancreas and gall bladder?

In other words, I want some one to describe a "digestive system analogy" in a crude comparison to the heart and lungs and pulmonary systems. Instead of using oxygen as a nutrient, you would use nutrient rich blood being exchange with blood being supplied for additional nutrient intake.

Any kind of comment - appreciated......