Absorption II Flashcards
Vitamin B12 and biliary salts are absorbed in
Terminal ilion
All absorbed molecules go to
Portal circulation
Lipids and liposoluble vitamins go to
Lymphatic circulation
Lumbar and hepatic lymphatic systems drain into
Cisterna chyli
Function of cisterna chyli
Accumulate lymph and recirculate them
2 systems that drain the lymphatics
Thoracic duct, main one
Left subclavian artery
Main elements of the lymph
Chylomicrons and immune cells
But carbohydrates and protein from drainage of capillary network are also included
L secreted along length of digestive system
7L
L passing through digestive tube in 24h
9L
mL of H2O eliminated daily
200 mL
What part is in charge of absorbing water for feces to be solid
Colon
Most of nutrients absorbed by
Small intestine
Colon absorbs
Water and vitamins
B12 absorption in
Terminal ilion
What protects Vitamin B12 from digestion
Haptocorrin HC
What proteolyses HC (Haptocorrin) in duodenum
Pancreatic proteoases
After HC has been proteolysed, VitB12 binds to
Intrsinsic factor, IF
What produced IF, intrinsic factor
Gastric parietal cels
IF + VitB12 go to terminal ileum where there is a high density of
Cubilin, which is a receptor of the microvilli
Iron in diet can be either in
Free form of bound to a heme group
Free iron is in the form of
Ferric iron 3+
What can only be absorbed by DMT1
Ferrous form of iron
Ferric iron –> ferrous iron through
Ferroductase
Ferroportin and hephaestin function
Release ferrous iron and transform it into ferric iron
