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17 Cards in this Set
- Front
- Back
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How much iron is there in the average North American adult diet?
Do men usually have a positive or negative iron balance? Do women usually have a negative or positive iron balance? |
10-20 mg
Men: positive iron balance Women: negative iron balance |
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What percentage of ingested iron is absorbed?
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5-10%
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Where in the digestive tract is iron absorbed?
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Duodenum
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Once it enters the blood stream, how does iron travel to RBC precursors in the bone marrow?
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Bound to the carrier protein transferrin
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To which carrier protein does iron bind to travel through the bloodstream?
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Transferrin
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What is transferrin?
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Carrier protein that carries iron through the blood from the GI tract or storage pool of the liver to the RBC precursor cells in the bone marrow
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In what form is iron stored?
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As part of the molecule ferritin
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What is ferritin?
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Iron storage molecule
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Where in the body is iron stored in the form of ferritin?
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Most ferritin is within hepatocytes, though minute quantities are present in plasma in equilibrium with intracellular ferritin
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Name 5 investigations that can be used to assess a patient's iron status.
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1) Bone marrow aspirate and stain (gold standard)
2) Serum ferritin 3) Serum iron 4) Total iron binding capacity (TIBC) 5) Saturation |
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Which test is the gold standard for evaluating a patient's iron status?
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Bone marrow aspiration
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Clinically, what is the single most important test for iron stores?
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Serum ferritin
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What precisely does serum iron measure?
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All non-heme iron present in blood (practically all of it bound to transferrin)
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What is total iron binding capacity (TIBC)?
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Measure of the total amount of transferrin present in blood
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What percentage of the TIBC is normally saturated with iron?
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Approx. 1/3
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What is iron saturation?
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Serum iron divided by TIBC expressed as a proportion or a percentage
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Name a situation in which a patient may have iron deficiency but a normal serum ferritin.
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Any situation leading to inflammation
Ferritin is an acute phase reactant and thus is released in times of inflammation |
