"Dan Marquez" <dmarquez3 at socal.rr.com> wrote in message
news:AdU9a.46518$aa.13710447 at twister.socal.rr.com...
> What is the mechanism that a nutrient gets transported from within a small
> intestine to the lymph or bloodstream? Are there pores of limited size?
You should be able to find this info in a Textbook of Physiology. There are
multiple mechanisms, for example active transport and transepithelial
transport. Lipids are packed into lipoprotein complexes.
> Once the nutrient is in the lymph or bloodstream, how does a "hungry" cell
> "grab" a desired nutrient?
Depends on the nutrient. For example, for lipids fractions there are
specialized membrane receptors.
> What makes the immune system think a nutrient is
> not an antigen?
Oral tolerance (involves Payer's Patches) doesn't always work so food
allergies may develop.