Iron metabolism: The Nutritional anemias (White) Flashcards
What are the normal iron compartments in the body?
(1) Hemaglobin
(2) Storage iron
(3) Myoglobin iron
(4) Labile pool
(5) Other tissue iron
(6) Transport iron.
How much iron is in 1ml of blood?
1ml of blood contains 2mg of iron
what are the characteristics of Ferritin?
Ferritin is a large hollow spherical protien that fills its core with 2000+ iron atoms.
What is the labile iron pool?
The labile iron pool is the iron that is leaving the plasma and entering interstitial and intracellular fluid compartments. (80-90g)
What are the characteristics of transferrin?
Transferrin carries iron in the plasma, it turns over 10 times a day, 1/3rd is saturated normally, syntheszied by the liver.
What are good sources of dietary iron?
Liver and meat are the best sources of dietary iron
How is iron absorption in the gut regulated?
Low iron leads to upregulation of iron transporters. Hepcidin prevents the release of iron from enterocytes to the blood via ferroportin.
What is ferroportin and how does it function?
Ferroportin transports iron out of cells. (macrophages, enterocytes, mother to fetus)
What are the functions of hepcidin?
Hepcidin is a negative regulator of iron uptake. Prevents iron from entering the plasma.
What factors increase absorption of non-heme iron?
reducing agents like ascorbic or gastric acid prevent absorption of non heme iron.
What are some factors that decrease the absorption of non-heme iron?
Insoluble complexes and chelating agents decrease the absorption of non heme iron.
What factors outside the GI tract increase absorption of iron?
(1) hypoxia
(2) Anemia
(3) Depletion of iron stores.
(4) Increased erythropoiesis.
What is the circular pathway of iron in the body?
Iron in the plasma is taken into the bone marrow and incroporated into RBCs. RBCs enter the blood stream. eventually RBCs are degraded in the spleen and the iron released back into the blood stream.
Why do infants need iron supplementation?
Milk is a poor source of iron.
What can cause malabsorption of iron?
(1) GI tract surgery
(2) Non-tropical sprue
(3) Picca
What are Billroth surgeries?
removal and resection of part of the stomach and small bowel.