A 45-year-old man is admitted 2 hours after vomiting blood from a duodenal ulcer. The bleeding is stopped at endoscopy that day, and he receives intravenous saline but no transfusion. Results: on admission, Hb 13.8 g/dL [138 g/L], reticulocytes 1.0%, WBC 12.9 × 10^3/µL [12.9 × 10^9/L] and platelets 395 × 10^3/µL [395 × 10^9/L]; on day 2, Hb 9.4 g/dL [94 g/L], reticulocytes 1.1%, serum erythropoietin 88 mIU/mL [88 IU/L] (reference 4-26 mIU/mL) and ferritin 120 ng/mL [120 µg/L] (reference 30-400 ng/mL); on day 8, Hb 9.9 g/dL [99 g/L] and reticulocytes 6.8% with polychromasia. The best explanation for the normal reticulocyte count on day 2 is:

Erythroid precursors need days to mature

Saline had diluted the reticulocytes

Erythropoietin was not yet released

Iron stores were too low to respond

A 66-year-old on hemodialysis has these results: hemoglobin 8.7 g/dL [87 g/L], MCV 89 fL, reticulocytes 0.4% (absolute 12 × 10^3/µL [12 × 10^9/L]), ferritin 420 ng/mL [420 µg/L], transferrin saturation 32%, normal WBC and platelet counts, and normal B12 and folate. What is the main cause of the anemia?

Too little erythropoietin from the kidneys

Hemolysis caused by the dialysis circuit

Failure of the marrow stem cells

Iron deficiency from dialysis blood loss

Production: hematopoiesis and maturation

18 ASCP MLS practice questions on Production: hematopoiesis and maturation, part of Hematology. The first 18 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Hard
A 45-year-old man is admitted 2 hours after vomiting blood from a duodenal ulcer. The bleeding is stopped at endoscopy that day, and he receives intravenous saline but no transfusion. Results: on admission, Hb 13.8 g/dL [138 g/L], reticulocytes 1.0%, WBC 12.9 × 10^3/µL [12.9 × 10^9/L] and platelets 395 × 10^3/µL [395 × 10^9/L]; on day 2, Hb 9.4 g/dL [94 g/L], reticulocytes 1.1%, serum erythropoietin 88 mIU/mL [88 IU/L] (reference 4-26 mIU/mL) and ferritin 120 ng/mL [120 µg/L] (reference 30-400 ng/mL); on day 8, Hb 9.9 g/dL [99 g/L] and reticulocytes 6.8% with polychromasia. The best explanation for the normal reticulocyte count on day 2 is:
1. ASaline had diluted the reticulocytes
2. BErythroid precursors need days to mature
3. CErythropoietin was not yet released
4. DIron stores were too low to respond
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Answer: B · Erythroid precursors need days to mature
After an acute bleed, falling oxygen delivery raises erythropoietin within hours, as the day 2 level of 88 mIU/mL shows. Erythropoietin acts on erythroid progenitors and early normoblasts, which then need several days to divide and mature into reticulocytes, so the reticulocyte count starts to rise after about 3 to 5 days and peaks at about 7 to 10 days. The hemoglobin was still normal on admission because whole blood had been lost and the plasma volume had not yet refilled; it fell once saline and fluid shifts diluted the remaining red cells. Dilution lowers red cells and reticulocytes together, so it does not lower the reticulocyte percentage, and the normal ferritin shows that iron was available. The reticulocytosis on day 8 confirms a normal marrow response.
- A: Dilution lowers red cells and reticulocytes equally, so the percentage is unchanged.
- C: Erythropoietin was already high on day 2.
- D: Ferritin is normal, and the marrow did respond by day 8.
Question 2 · Medium
Which cell arises from the common lymphoid progenitor rather than the common myeloid progenitor?
1. ABasophil
2. BNatural killer cell
3. CMonocyte
4. DMegakaryocyte
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Answer: B · Natural killer cell
The stem cell gives rise to two main progenitors. The common lymphoid progenitor produces T cells, B cells and natural killer (NK) cells. The common myeloid progenitor (CFU-GEMM) produces granulocytes, monocytes, red cells and megakaryocytes. NK cells are large granular lymphocytes that kill virus-infected and tumor cells without prior sensitization.
- A: Basophils are granulocytes and arise from the myeloid line.
- C: Monocytes come from the granulocyte-monocyte progenitor, a myeloid cell.
- D: Megakaryocytes come from the myeloid megakaryocyte-erythroid progenitor.
Question 3 · Easy
In neutrophil maturation, specific (secondary) granules first appear in the:
1. AMetamyelocyte
2. BMyelocyte
3. CPromyelocyte
4. DMyeloblast
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Answer: B · Myelocyte
Primary (azurophilic) granules form at the promyelocyte stage. Specific granules start to form at the myelocyte stage, and from then on the cell can be identified as a neutrophil, eosinophil or basophil. The myelocyte is also the last granulocytic stage that can divide. Metamyelocytes, bands and segmented neutrophils mature without dividing.
- A: Specific granules are already present before the metamyelocyte stage.
- C: Promyelocytes make the primary (azurophilic) granules, not the specific granules.
- D: Myeloblasts usually have no visible granules.
Question 4 · Hard
A 66-year-old on hemodialysis has these results: hemoglobin 8.7 g/dL [87 g/L], MCV 89 fL, reticulocytes 0.4% (absolute 12 × 10^3/µL [12 × 10^9/L]), ferritin 420 ng/mL [420 µg/L], transferrin saturation 32%, normal WBC and platelet counts, and normal B12 and folate. What is the main cause of the anemia?
1. AHemolysis caused by the dialysis circuit
2. BFailure of the marrow stem cells
3. CIron deficiency from dialysis blood loss
4. DToo little erythropoietin from the kidneys
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Answer: D · Too little erythropoietin from the kidneys
Diseased kidneys make too little erythropoietin for the degree of anemia, so the marrow under-produces red cells. The result is a normocytic, normochromic anemia with a low reticulocyte count. Here the ferritin and transferrin saturation show adequate iron, the low reticulocyte count argues against hemolysis, and normal white cell and platelet counts argue against marrow failure. Treatment is an erythropoiesis-stimulating agent, with iron given to keep stores adequate.
- A: Hemolysis would raise the reticulocyte count, which is low here.
- B: Stem cell failure would also lower the white cells and platelets, which are normal.
- C: Ferritin 420 ng/mL and transferrin saturation 32% show adequate iron, and the MCV is normal.
Question 5 · Easy
Which is the last stage of red cell development that can still divide?
1. AReticulocyte
2. BPolychromatic normoblast
3. COrthochromic normoblast
4. DBasophilic normoblast
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Answer: B · Polychromatic normoblast
The pronormoblast, basophilic normoblast and polychromatic normoblast can all divide, so one pronormoblast gives rise to about 8 to 32 red cells. Once the cell becomes an orthochromic normoblast, its nucleus is condensed and it can no longer divide. The orthochromic normoblast then pushes out its nucleus to become a reticulocyte. A reticulocyte has no nucleus and cannot divide.
- A: Reticulocytes have no nucleus and cannot divide.
- C: Orthochromic normoblasts have a condensed nucleus and cannot divide.
- D: Basophilic normoblasts divide, but a later stage also divides.
Question 6 · Medium
Renal cells raise their erythropoietin output when tissue oxygen falls, because:
1. AHypoxia-inducible factor is no longer degraded
2. BThrombopoietin binds to receptors on renal cells
3. CHepcidin from the liver rises and signals the kidney
4. DIron stored in the kidney is released into plasma
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Question 7 · Medium
As a normoblast matures toward a reticulocyte, which change is seen on a Wright-stained marrow film?
1. ANucleoli become more prominent
2. BNucleus enlarges and chromatin opens up
3. CCytoplasm shifts from blue to pink-orange
4. DCell size increases at each stage
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Question 8 · Medium
Normoblasts in the marrow cluster around a central macrophage, forming an erythroblastic island. One function of this macrophage is to:
1. AMake globin chains for the normoblasts
2. BIngest the nuclei extruded by normoblasts
3. CProduce erythropoietin for the cluster
4. DDestroy reticulocytes before release
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Question 9 · Hard
A 500-cell bone marrow differential counts 330 granulocytes and their precursors, 110 nucleated erythroid precursors, and 60 lymphocytes and plasma cells. What is the myeloid-to-erythroid (M:E) ratio?
1. A0.33:1
2. B3.0:1
3. C4.5:1
4. D3.5:1
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Question 10 · Hard
Two patients have platelet counts of 12 × 10^3/µL [12 × 10^9/L]. Patient A has aplastic anemia with very few marrow megakaryocytes. Patient B has immune thrombocytopenia with plentiful megakaryocytes. Plasma thrombopoietin (TPO) is high in A but near normal in B. The best explanation is:
1. AMegakaryocytes and platelets bind and clear TPO
2. BThe liver makes more TPO when platelets fall
3. CAntiplatelet antibodies neutralize TPO in B
4. DHypoxia stimulates TPO release in aplastic anemia
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Question 11 · Easy
A megakaryocyte becomes polyploid because it copies its DNA again and again without dividing. This process is called:
1. AEndomitosis
2. BApoptosis
3. CMeiosis
4. DCytokinesis
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Question 12 · Easy
At about 3 months of gestation, most of the fetus's blood cells are made in the:
1. ALiver
2. BYolk sac
3. CBone marrow
4. DThymus
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Question 13 · Easy
Hematopoietic stem cells collected for transplant are counted by flow cytometry using which surface marker?
1. ACD41
2. BCD3
3. CCD34
4. DCD19
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Question 14 · Medium
How do mature megakaryocytes release platelets into the blood?
1. AMegakaryoblasts divide to form small platelets
2. BWhole megakaryocytes break apart in the spleen
3. CProplatelets shed platelets into marrow sinuses
4. DCirculating monocytes bud off small platelets
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Question 15 · Medium
A healthy student's WBC count rises from 5.8 to 9.4 × 10^3/µL [5.8 to 9.4 × 10^9/L] within minutes of a hard sprint, with no immature cells. The best explanation is:
1. ANew neutrophils released from the marrow storage pool
2. BMarginated neutrophils entering the circulating pool
3. CFaster division of myelocytes in the marrow
4. DLonger survival of neutrophils in the blood
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Question 16 · Easy
Where is thrombopoietin, the main growth factor for megakaryocytes, mainly produced?
1. AKidney
2. BLiver
3. CLungs
4. DSpleen
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Question 17 · Easy
Most of the body's erythropoietin is made by:
1. AMacrophages in the spleen
2. BStromal cells in the marrow
3. CHepatocytes in the liver
4. DPeritubular cells of the kidney
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Question 18 · Medium
After chemotherapy, a patient is given filgrastim (G-CSF). Three days later the neutrophils are rising, with many bands, some metamyelocytes and toxic granulation. These changes most likely reflect:
1. ANew acute myeloid leukemia
2. BChronic myeloid leukemia
3. CNormal response to G-CSF
4. DTherapy-related myelodysplasia
Answer and explanation in LearnFree account

Production: hematopoiesis and maturation

Which cell arises from the common lymphoid progenitor rather than the common myeloid progenitor?

In neutrophil maturation, specific (secondary) granules first appear in the:

Which is the last stage of red cell development that can still divide?

Renal cells raise their erythropoietin output when tissue oxygen falls, because:

As a normoblast matures toward a reticulocyte, which change is seen on a Wright-stained marrow film?

Normoblasts in the marrow cluster around a central macrophage, forming an erythroblastic island. One function of this macrophage is to:

A 500-cell bone marrow differential counts 330 granulocytes and their precursors, 110 nucleated erythroid precursors, and 60 lymphocytes and plasma cells. What is the myeloid-to-erythroid (M:E) ratio?

Two patients have platelet counts of 12 × 10^3/µL [12 × 10^9/L]. Patient A has aplastic anemia with very few marrow megakaryocytes. Patient B has immune thrombocytopenia with plentiful megakaryocytes. Plasma thrombopoietin (TPO) is high in A but near normal in B. The best explanation is:

A megakaryocyte becomes polyploid because it copies its DNA again and again without dividing. This process is called:

At about 3 months of gestation, most of the fetus's blood cells are made in the:

Hematopoietic stem cells collected for transplant are counted by flow cytometry using which surface marker?

How do mature megakaryocytes release platelets into the blood?

A healthy student's WBC count rises from 5.8 to 9.4 × 10^3/µL [5.8 to 9.4 × 10^9/L] within minutes of a hard sprint, with no immature cells. The best explanation is:

Where is thrombopoietin, the main growth factor for megakaryocytes, mainly produced?

Most of the body's erythropoietin is made by:

After chemotherapy, a patient is given filgrastim (G-CSF). Three days later the neutrophils are rising, with many bands, some metamyelocytes and toxic granulation. These changes most likely reflect: