The diagram above traces (and magnifies) a villus from the duodenum slide (can you find which one?).  
The outer region is the actual epithelial layer.  It has numerous goblet cells and the lumenal surface has 
microvilli which increase the surface area for absorption.  These microvilli show up on high magnification 
as the "Brush Border".
     The deeper regions of the villus constitutes the lamina propria which also extends towards the submucosa.  
This region of the villus contains the blood vessels that absorb the nutrients from our intestines.  They carry 
most of the water soluble (hydrophylic or lipophobic) nutrients to the Portal System which enters the liver, 
the body's detox-center.  As much as 85% of some water soluble, oral medications are degraded by a single pass 
through the liver (a fact that must be considered when prescribing meds as a clinician).  
     Also found in Lamina Propria of the villus are the lacteals.  These are tiny lymph vessels.  A great deal 
of the lipids you ingest DO NOT enter the vessels mentioned above.  They enter the lacteals.  This means they by-pass 
the liver's detoxification.  These lymphatic vessels drain into the thoracic duct which empties directly into 
the circulatory system, ususlly between the left internal and external jugular veins.  Therefore, 
any lipid soluble toxins (pesticides, etc.) or drugs enter the circulatory system without going through the detox-center.  
This also means that the lipids from a high-lipid diet enter the circulatory system with minimal alteration.....