Question 1

What is the plasma carrier protein for iron?&#10;A)apoferritin&#10;B)apotransferrin&#10;C)albumin&#10;D)hemosiderin

Accepted Answer

Apotransferrin is the carrier protein for iron.Apoferritin and hemosiderin are storage forms of iron.Albumin is a carrier protein for many substances but not for iron.

Question 2

The serum ferritin is used more often than bone marrow or liver biopsies to assess iron stores because it is&#10;A)a more direct measurement.&#10;B)more accurate.&#10;C)more precise.&#10;D)less invasive.

Accepted Answer

The measurement of ferritin is performed on a serum sample;therefore,it requires nothing more than a venipuncture to obtain a blood specimen.It is proportional to the iron in stores,but it is not a more direct measurement.In fact,a bone marrow biopsy followed by staining with Prussian blue to assess iron stores (in the form of hemosiderin)is perhaps the best measurement of iron stores that are readily available for use in hemoglobin synthesis.This is much more invasive.

Question 3

What is the mechanism for iron toxicity if iron is present in excess amounts?&#10;A)acts as a catalyst in forming hydroxyl (free) radicals&#10;B)impedes hematopoiesis&#10;C)reduces hemoglobin to methemoglobin&#10;D)interferes with globin synthesis

Accepted Answer

Iron has reduction (redox)potential,and easily cycles between ferrous (reduced)and ferric (oxidized)forms.If it is found in excess,it plays a key role in forming harmful oxygen radicals that can damage cellular structures,harming cells in the process.

Question 4

Which of the following is true for apotransferrin?&#10;A)It can bind two molecules of ferric iron.&#10;B)It binds to a ferritin receptor found on the cell membrane.&#10;C)It is synthesized in the kidney.&#10;D)It is normally about 50% saturated with iron.

Accepted Answer

Transferrin binds two molecules of ferric iron.It binds to receptors on the cell membrane,which are called transferrin receptors.It is synthesized in the liver and is normally about one third saturated.

Question 5

Which two organs are the major storage sites for iron in a normal individual?&#10;A)lymph nodes and muscle&#10;B)bone marrow and pancreas&#10;C)spleen and heart&#10;D)liver and spleen

Accepted Answer

The liver and spleen have a large amount of apoferritin,the protein that stores iron;they thus are major storage sites for iron.

Question 6

Soluble transferrin receptor (sTfR)levels increase when intracellular iron levels are&#10;A)decreased.&#10;B)elevated.&#10;C)constant.&#10;D)both a and b.

Accepted Answer

When iron is deficient,the concentration of transferrin receptors (sTfR)increases.sTfR levels are decreased when iron levels are elevated,such as in chronic disease.

Question 7

A patient has a serum iron of 10 g/dL and a total iron-binding capacity (TIBC)of 490 g/dL.What is the percent saturation of transferrin?&#10;A)2%&#10;B)25%&#10;C)40%&#10;D)60%

Accepted Answer

Percent transferrin saturation is calculated by dividing the serum iron by TIBC and multiplying by 100.Thus in the example here,% saturation = (10/490)x100 = 2%.

Question 8

Which of the following stains blue with the Prussian blue stain?&#10;A)ferritin&#10;B)hemosiderin&#10;C)transferrin&#10;D)both ferritin and hemosiderin

Accepted Answer

Only the insoluble form of storage iron,which is hemosiderin,stains with the Prussian blue stain.Ferritin is soluble and is not stained.

Question 9

The serum iron and TIBC results given in Question 7 are consistent with:&#10;A)iron overload.&#10;B)iron toxicity.&#10;C)iron deficiency.&#10;D)acute infection.

Accepted Answer

A percent saturation of 2% is consistent with severe iron deficiency.Under normal circumstances approximately one third of transferrin is saturated with iron.Iron overload and iron toxicity are situations in which the percent saturation would be high.In an acute infection,the anemia of chronic inflammation (also called anemia of chronic disease)might develop if the infection becomes chronic.Percent saturation would be decreased below normal,but it would not become this low (and the infection would have to be fairly long-standing and chronic).

Question 10

Select the condition where an acute increase in ferritin levels can be detected without a specific increase in the amount of systemic body iron?&#10;A)myocardial infarction&#10;B)bacterial infection&#10;C)malignancy&#10;D)liver disease

Accepted Answer

Ferritin levels are acutely increased when a patient has a bacterial infection.This is a response of the body to sequester the iron away from the bacteria.These increases can be subtle and may or may not be outside the reference interval.

Question 11

Where is the largest percentage of iron in the body located?&#10;A)stored in the bone marrow&#10;B)stored in the liver&#10;C)attached to hemoglobin in erythrocytes&#10;D)in the cytoplasm of macrophages

Accepted Answer

The answer of Where is the largest percentage of iron...

Question 12

Acute (24-hour)assessment of the amount of iron that is available for hemoglobin production is best identified by measuring the&#10;A)sTfR levels on the cell membrane.&#10;B)amount of hemoglobin in reticulocytes.&#10;C)amount of hemosiderin with Prussian blue stain.&#10;D)zinc protoporphyrin levels in red blood cells.

Accepted Answer

The answer of Acute (24-hour)assessment of the amount of iron...

Question 13

Good dietary sources of iron include all except&#10;A)meat.&#10;B)fruit.&#10;C)fortified flour.&#10;D)legumes.

Accepted Answer

The answer of Good dietary sources of iron include all...

Question 14

Heme is composed of iron and&#10;A)globin chains.&#10;B)oxygen.&#10;C)methemoglobin.&#10;D)protoporphyrin IX.

Accepted Answer

The answer of Heme is composed of iron and&#10;A)globin chains.&#10;B)oxygen.&#10;C)methemoglobin.&#10;D)protoporphyrin...

Deck 11: Iron Kinetics and Laboratory Assessment