Chap 8 Flashcards
Iron Metabolism
Primary function of Iron in the body?
Oxygen transport and storage
70% of the body’s total iron is stored where?
In the hemoglobin of RBCs
Iron absorption and storage are influenced by?
Amount and type of available iron in the diet. (Nutritional Deficiency)
Which part of Iron metabolism can be effected by GI tract problems?
Can cause incomplete absorption.
Example of increased demand?
Pregnancy
The growth years
Examples of excessive loss of Iron?
Acute or Chronic Hemorrhage
(Female’s period during child-bearing years) (GI bleeding in men).
Iron-containing compounds assist distribution through?
Functional (assist enzymatic &metabolic functions).
Transportation or Storage
Iron locations, besides blood?
Macrophages of spleen and liver (RBC destruction, liberating Iron).
Hepatocytes and Enterocytes (Iron storage)
Forms of Iron?
Non-heme
Heme
Non-Heme Iron is described as?
Ionic/Ferric
In veggies and whole grains.
2-20% absorbed
Heme Iron is described as?
In red meats
Easily absorbed
5-35% absorbed
Iron transport is a mechanism of?
Transferrin
Transferrin
Transports iron to the BM, for use in Hgb synthesis.
Synthesized by the liver.
Iron storage is a mechanism of?
Ferritin
Where is Iron primarily stored?
The liver
Ferritin
Soluble iron, W/ quick release for heme synthesis.
Hemosiderin
Partially degraded iron, W/ a slow release.
The iron pools in the body?
Hgb (Largest)
Storage Iron (Ferritin) Available
Myoglobin (Tissue Hgb)
Tissue Iron (Enzymes)
Transport (Transferrin)
The functional pool of Iron?
Hgb Iron in the blood.
Myoglobin Iron in the muscles.
Iron in Peroxidase, Catalase, Cytochromes, Riboflavin, enzymes in all cells.
Hgb Iron in the blood? (% or g)
68% or 2400g
Myoglobin iron in muscles? (% or g)
10% or 0.360g
Iron in Peroxidase, Catalase, Cytochromes, Riboflavin Enzymes in all cells? (% or g)
3% or 0.120g
The storage pool of Iron?
Ferritin and Hemosiderin (mostly in Macrophages & Hepatocytes, small amount in all cells except mature RBCs).
Storage Iron? (% or g)
18% or 0.667g
The transport pool of Iron?
Transferrin in plasma
Transport Iron? (% or g)
< 1% or 0.001g
Serum Ferritin (SF) adult reference range?
40-400 ng/mL
What does the SF indicate diagnostically?
Iron stores
Serum Iron (SI) adult reference range?
50-160 umol/L
What does SI indicate diagnostically?
Available transport Iron
Total Iron Binding Capacity (TIBC) reference range?
250-400 ug/dL
What does TIBC indicate diagnostically?
Indirect indicator of Iron stores.
Transferrin Saturation (TS) reference range?
20-55%
What does TS indicate diagnostically?
Indirect indicate of Iron stores W/ Transport Iron.
Transferrin Receptor (TR) reference range?
1.15-2.75 mg/L
What does TR indicate diagnostically?
Functional Iron available
RBC Zinc Protoporphyrin reference range?
< 80 mg/dL of RBCs
What does the RBC zinc protoporphyrin indicate diagnostically?
Functional Iron available in RBCs.
Hemochromatosis
A condition caused by increased Iron absorption and deposits in vital organs, (I.E. liver, spleen and pancreas) that then become fibrotic.
Clinical Symptoms of Hemochromatosis?
Hyperpigmentation of skin
Laboratory Findings?
Increased: Iron and Ferritin
Decreased: TIBC and Transferrin
How is hemochromatosis treated?
Therapeutic Phlebotomy or chelation drugs.
Porphyria
Excessive production of porphyrins in the BM. (Or liver)The excess accumulates in developing RBCs.
Porphyria is caused by?
Defect in 1 or more of the enzymes in heme synthesis pathway.
What is another name for PTs W/ Porphyria?
OG Vampires or Werewolves due to their skin photosensitivity to the sun.
