Chapter 12 (first part of lecture): Overview of Cell Types of the Bone Marrow

Question 1

What is meant by hematopoiesis?

Answer 1

Differentiation of stem cells to mature blood cells under the influence of growth factors and cytokines.

Question 2

Why is hematopoiesis important?

Answer 2

Because it keeps the number of blood cells stable if there is more or less demand.

Question 3

What function does IL-3 have in hematopoiesis?

Answer 3

It stimulates early precursor cells to differentiate.

Question 4

What function does erythropoietin have in hematopoiesis?

Answer 4

It stimulates the bone marrow to produce red blood cells.

Question 5

Which protein is involved in the process of megakaryopoiesis?

Answer 5

Thrombopoietin

Question 6

What is meant by myelopoiesis?

Answer 6

The production of bone marrow and of all cells that arise from it. BUT in a narrower sense, myelopoiesis also refers specifically to the formation of myeloid leukocytes (myelocytes), like eosinophilic/basophilic granulocytes.

Question 7

In what process are colony stimulating factors (G-CSFs) and granulocyte-macrophage colony stimulating factors (GM-CSF) involved?

Answer 7

Myelopoiesis

Question 8

What are clues for the size of the erythrocyt and the quantity of hemoglobin in the cell?

Answer 8

Mean Corpuscular Volume (MCV): average size of red blood cells.

Mean Corpuscular Hemoglobin (MCH): average quantitiy of hemoglobin present in a single red blood cell.

Mean Corpuscular Hemoglobin Concentration (MCHC): concentration of hemoglobin in all red blood cells

Question 9

What is the common progenitor of basophils, eosinophils, neutrophils, monocytes, platelets and erythrocytes?

Answer 9

Myeloid stem cell

Question 10

Fill in:

The erythrocyt originates from a … (1), which differentiates into …(2), loses its … (3) and can stay alive for approximately … (4) days.

Answer 10

1. (myeloid) stem cell
2. erythroblast
3. nucleus
4. 150

Question 11

What is the function of erythrocytes?

Answer 11

Transport of O2 to tissues and CO2 from tissues.

Question 12

What are characteristics of neutrophils?

Answer 12

• Segmented nucleus (3-5 lobes)
• Fine, pink, granula
• Short lifespan
• After leaving the bone marrow the neutrophils circulate through the blood towards the tissues
• Cleans up the mess (dead bacteria, tissue remnants)

Question 13

What are characteristics of lymphocytes?

Answer 13

• Small round cells, dark and compact nucleus, a small rim of cytoplasm
• Some lymphocytes have small red granules

Question 14

What are characteristics of thrombocytes?

Answer 14

• Small cytoplasmic fragments of the megakaryocytes in the bone marrow
• Granulae of thrombocytes contain coagulation factors, growth factors and ADP.