Iron Metabolism and Erythropoiesis Quiz
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Questions and Answers

What is the primary source of iron required for erythropoiesis?

  • Iron stored in the liver
  • Iron absorbed from green vegetables
  • Dietary iron from recent meals
  • Recycled iron from the destruction of red blood cells (correct)

    • What is the average daily requirement of iron in adult males?

  • 1 mg/day (correct)
  • 5 mg/day
  • 2 mg/day
  • 10 mg/day

    • What percentage of dietary iron is typically reabsorbed in a normal adult?

  • 20%
  • 50%
  • 10% (correct)
  • 40%

    • What is the average total iron content in an adult human body?

    <p>3.5-4.0 gm</p> Signup and view all the answers

    What is the main role of iron in the body related to hemoglobin?

    <p>To form the structure of hemoglobin for oxygen transport</p> Signup and view all the answers

    Which factor does NOT increase the daily iron requirements?

    <p>Age above 50</p> Signup and view all the answers

    What form of iron is absorbed in the small intestines after conversion?

    <p>Fe+2</p> Signup and view all the answers

    What is the role of Transferrin in iron metabolism?

    <p>Transport Fe+3 in the bloodstream</p> Signup and view all the answers

    In which of the following locations is iron NOT typically stored in the body?

    <p>Lungs</p> Signup and view all the answers

    Which protein is responsible for the conversion of iron from Fe+2 to Fe+3?

    <p>Ferroxidase</p> Signup and view all the answers

    What is the relationship between transferrin receptor levels and the amount of iron in the body?

    <p>They are inversely proportional.</p> Signup and view all the answers

    Which of the following is the best index for iron depletion?

    <p>Ferritin level</p> Signup and view all the answers

    What does increased Zinc Protoporphyrin (ZPP) indicate in the context of iron deficiency?

    <p>Excess protoporphyrin formation.</p> Signup and view all the answers

    How is the Transferrin Saturation calculated?

    <p>Ser.Fe / TIBC x 100%</p> Signup and view all the answers

    What effect do inflammatory states have on ferritin levels?

    <p>They increase ferritin levels.</p> Signup and view all the answers

    What is the Minimum Daily Requirement of iron for a pregnant or lactating woman?

    <p>3.0 mg</p> Signup and view all the answers

    Which food category is classified as high in iron?

    <p>Organ meats</p> Signup and view all the answers

    Which of the following substances decreases iron absorption?

    <p>Phytates</p> Signup and view all the answers

    Sideroblasts are found in which location when referring to iron storage?

    <p>Bone marrow</p> Signup and view all the answers

    What form of iron is stored when excess iron exceeds the ferritin storage capacity?

    <p>Hemosiderin</p> Signup and view all the answers

    Which of the following increases iron absorption?

    <p>Ascorbic acid (vitamin C)</p> Signup and view all the answers

    What term describes the insoluble form of stored iron?

    <p>Hemosiderin</p> Signup and view all the answers

    What is the Minimum Daily Requirement of iron for a nonmenstruating adult woman?

    <p>1.0 mg</p> Signup and view all the answers

    What is the role of Hepcidin in iron metabolism?

    <p>Inhibits iron release from macrophages during iron overload</p> Signup and view all the answers

    Which laboratory evaluation is a measure of transferrin-bound iron?

    <p>Serum Fe</p> Signup and view all the answers

    During which period would a low birth weight infant be at risk for iron deficiency due to lack of supplements?

    <p>Infancy</p> Signup and view all the answers

    What does Total Iron Binding Capacity (TIBC) indicate?

    <p>Amount of iron that transferrin can bind at one time</p> Signup and view all the answers

    Which group is at heightened risk for iron deficiency due to fad diets during adolescence?

    <p>Adolescents facing dietary restrictions</p> Signup and view all the answers

    What condition is likely to lead to an increase in Hepcidin levels?

    <p>Iron overload conditions</p> Signup and view all the answers

    What is most likely indicated by a high Total Iron Binding Capacity (TIBC)?

    <p>Iron deficiency anemia</p> Signup and view all the answers

    Which of the following is NOT included in a typical laboratory assessment of iron status?

    <p>Hemoglobin levels</p> Signup and view all the answers

    What percentage of iron from an average Western diet is typically absorbed by the body?

    <p>5-10%</p> Signup and view all the answers

    Which iron state is essential for effective absorption in the diet?

    <p>Ferrous state</p> Signup and view all the answers

    Which protein binds up to 4500 iron atoms for storage?

    <p>Ferritin</p> Signup and view all the answers

    What primarily influences the absorption of iron from the diet?

    <p>Type of iron consumed</p> Signup and view all the answers

    In which state is iron primarily transported within the body after absorption?

    <p>Bound to transferrin</p> Signup and view all the answers

    Which of the following factors is NOT listed as affecting iron absorption?

    <p>Dietary protein content</p> Signup and view all the answers

    What structural feature is characteristic of transferrin?

    <p>Transmembrane glycoprotein dimer</p> Signup and view all the answers

    Which of the following sobre iron metabolism is true regarding hemosiderin?

    <p>It can be revealed by H&amp;E stain as golden brown granules.</p> Signup and view all the answers

    What is the total body iron content in a 70-kg adult male approximately?

    <p>3500 mg</p> Signup and view all the answers

    During pregnancy, what happens to iron absorption?

    <p>It can increase significantly, up to 20-30%.</p> Signup and view all the answers

    Study Notes

    Iron Metabolism & Hypochromic Anemias

    • Objectives include:
      • Describing iron's role in hemoglobin
      • Outlining normal iron metabolism, distribution, and requirements
      • Discussing iron absorption and transport
      • Evaluating lab tests to identify types of anemia (e.g., IDA, sideroblastic anemia)

    Normal Iron Metabolism, Distribution, and Requirements

    • Iron in food is present as ferric hydroxide compounds (found in liver, meat, and green vegetables).

    • Average daily iron requirement for adult males is 1 mg.

    • Total average iron in adults is 3.5-4 gm.

    • 2/3 of total iron is used in hemoglobin (Hb) synthesis.

    • 1/3 is used in other components (myoglobin, electron transport proteins, myeloperoxidase).

    • 95% of iron needed for erythropoiesis is from recycled iron from red blood cell (RBC) destruction and Hb metabolism.

    • Total daily dietary iron intake in a healthy adult is 10-20 mg.

    • Only 10% (1-2 mg) of dietary iron is reabsorbed to balance loss in feces, sweat, urine.

    • Remaining iron is stored in the liver, spleen, bone marrow, myoglobin, electron transport proteins, myeloperoxidase.

    Daily Requirements, Absorption, and Transport

    • Infant: 1 mg iron
    • Child: 0.5 mg iron
    • Menstruating woman: 2 mg iron
    • Pregnant/lactating woman: 3 mg iron
    • Adult males/non-menstruating woman: 1 mg iron
    • Physiologic and pathologic factors impact iron requirements (e.g., growth spurts, menstruation, pregnancy, lactation).

    Iron Absorption

    • Iron is absorbed mainly in the small intestines
    • Stomach acid converts ferric iron (Fe+3) to ferrous iron (Fe+2)
    • Ferrous iron moves from the intestinal cells into the bloodstream.
    • Iron is converted to ferric iron (Fe+3) by serum ferroxidase.
    • Transport protein, transferrin, carries ferric iron to bone marrow for heme synthesis and to muscles for myoglobin synthesis.

    Iron Storage

    • Iron is stored in mononuclear phagocytic systems in bone marrow, liver, and spleen's reticuloendothelial (RE) system
    • Excess iron is stored as ferritin (water-soluble) , easily mobilized
    • Excess iron is stored as hemosiderin (insoluble form, in macrophages).

    Laboratory Evaluation of Iron Status

    • Serum iron measures transferrin-bound iron.
    • Early morning specimens are ideal for serum iron assay
    • Total iron-binding capacity (TIBC) is the iron-binding capacity of transferrin.
    • Transferrin saturation (TsS) assesses the proportion of transferrin bound with iron (TS% = Serum Fe/TIBC x 100).
    • Ferritin shows iron storage status.
    • Transferrin receptors (TsRs) are inversely proportional to iron stores.
    • Free erythrocyte protoporphyrin (FEP) and zinc protoporphyrin (ZPP).
    • Reticulocyte production index (RPI) helps evaluate bone marrow function.
    • Assessment of body iron status include measurements of serum iron, total iron-binding capacity (TIBC), transferrin saturation (iron/TIBC x100), serum ferritin, serum transferrin receptor (sTfR), red cell zinc protoporphyrin (ZPP), and percentage of hypochromic red cells.

    Hypochromic Anemias

    • Hypochromic anemias result from defects in hemoglobin synthesis, while DNA synthesis remains normal.

    Causes of Iron-Deficiency Anemia

    • Inadequate iron absorption (e.g., inflammatory bowel disease, gastric bypass, celiac disease, resection of the small bowel)
    • Decreased iron intake (e.g., a diet deficient in iron-rich foods) or increased iron loss (e.g., blood loss, heavy menses, pregnancy, infections)
    • Increased iron needs (e.g., pregnancy, growth spurts, blood loss).
    • Iron misappropriation (e.g., chronic blood loss, parasitic infections, infections, malignancies, trauma).

    Iron Overload

    • Increased iron absorption
    • Excess oral iron administration
    • Excessive blood transfusions.

    Anemia of Chronic Disease (ACD)

    • Impaired iron release from storage, associated with high hepcidin levels.
    • High hepcidin levels affect iron absorption and macrophage iron release
    • Inflammation and infection often cause hepcidin elevation.

    Sideroblastic Anemia

    • Defects in heme synthesis, resulting in ineffective erythropoiesis.
    • Two groups: primary (irreversible) and secondary (potentially reversible).
    • Diagnosed by increased iron levels in bone marrow.

    Iron Deficiency Anemia - Clinical Symptoms

    • General symptoms (fatigue, weakness, dizziness, pallor)
    • Epithelial changes: smooth red tongue (glossitis), angular stomatitis, and koilonychia (spoon-shaped nails)

    Porphyrias

    • Inherited disorders affecting heme synthesis and leading to porphyrin accumulation.
    • Classified as acute or non-acute based on clinical presentation, and as erythropoetic or hepatic.

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    Related Documents

    Iron Metabolism & Hypochromic Anemia PDF

    Description

    Test your knowledge on the essential role of iron in erythropoiesis and its metabolism within the human body. This quiz covers iron sources, daily requirements, absorption rates, and storage locations. Challenge yourself to understand the vital functions of iron related to hemoglobin and the factors affecting its metabolism.

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