Haemopoiesis

Question 1

What is haemopoiesis?

Answer 1

A tightly regulated process that forms blood cells

Question 2

What are the processes of haemopoiesis?

Answer 2

1. Erythropoiesis- red cell production (erythrocytes). Transport 0₂ from lungs to tissues
2. Leucopoiesis- white cell production (leucocytes) defend body against infection
3. Thrombopoiesis- platelet production (thrombocytes) prevent blood loss at site of injury

Question 3

Label this diagram

Answer 3

Question 4

What is haemopoiesis regulated by?

Answer 4

• Growth factors
• Cytokines
• Environmental factors
• Apoptosis

Question 5

Ontogeny of Haemopoiesis in adults, infants and foetus

Answer 5

Adults

•Bone marrow of Vertebrae, ribs, sternum, skull, sacrum and pelvis, proximal ends of femurv

Infants

•Bone marrow (practically all bones)

Foetus

• 0–2 months (yolk sac of embryo)
• 2–7 months (liver, spleen)
• 5–9 months (bone marrow)- at birth sole site

Question 6

Haemopoietic stem and progenitor cells

Answer 6

Haemostasis begins with pluripotent stem cell also called haemopoetic stem cell there are about 11000-22000 per individual

Question 7

Bone marrow stroma

Answer 7

Question 8

One single cell can secrete many different growth factors in response to various stimuli, each can impact on:

Answer 8

1. Different cell types
2. Have a different effect when they are acting lone or in combination with other growth factors
3. Sequence of a growth factors activity

Question 9

Give some examples of growth factors

Answer 9

Question 10

Summary: role of growth factors in haemopoiesis

Answer 10

Question 11

Apoptosis is programmed cell death

Morphologically it is characterised by:

Answer 11

1. Cell shrinkage
2. Condensation of nuclear chromatin
3. Fragmentation of the nucleus
4. Cleavage of DNA at internucleosomal sites

Question 12

What is erythropoesis?

Answer 12

Formation of RBC

Question 13

What is the normal concentration of RBC in the blood?

Answer 13

Normal concentration in the blood 3.9-6.5 X 10¹²/L

Question 14

Key steps involved in red cell development from a blast cell involve:

Answer 14

1. slow reduction in size
2. loss of the nucleus to become a reticulocyte

Process occurs in parallel with development of Haemoglobin

Question 15

Draw the process of erythropoiesis

Answer 15

Question 16

Reticulocytes

Answer 16

Question 17

Erythropoiesis is regulated by

Answer 17

EPO

Question 18

What things stimulate EPO

Answer 18

• Atmosphere 0₂ is low
• Defective cardiac/pulmonary function
• Damage to the renal circulation

Question 19

EPO levels

Answer 19

Question 20

What is thrombopoiesis?

Answer 20

Platelet production

Question 21

Draw thrombopoiesis

Answer 21

Question 22

Draw granulopoiesis

Answer 22

•IL-1, IL3, GM-CSF and M-CSF control proliferation and differentiation.

Question 23

Show the mature granulocytes (Neutrophils and Eosinophils)

Answer 23

Question 24

Show the mature granulocytes (Basophils and monocytes)

Answer 24

Question 25

Lymphocyte production

Answer 25

* B and T cells – both arise from the Haemopoietic * stem cell (IL-7)

Question 26

Describe B-cells and the BCR

Answer 26

B cell receptor is membrane bound, after activation secreted as immunoglobulin proteins IgA, IgG,IgM,IgD,IgE

Question 27

T cells develop in the

Answer 27

Thymus

Question 28

Helper T cells express

Answer 28

CD4

Question 29

Cytotoxic T cells express

Answer 29

CD8

Question 30

What is marrow analysis?

Answer 30

* Status of and capability for blood cell production. * Measure blood cell production, to help diagnose: **leukaemia** **bone marrow disease** **spread of cancer** **severe anaemia** Cultured for the presence of microorganisms

Question 31

Obtaining bone marrow

Answer 31

* Hip bone (pelvic bone), but it also can be done from the breastbone, lower leg bone or backbone * Cleaned with iodine solution or alcohol. Local aesthetic injected * Bone marrow needle is then placed through the skin and into the bone. * **Bone marrow aspiration** * **Bone marrow biopsy**

Question 32

Once aspirated bone marrow is smeared onto a slide and stained for examination:

Answer 32

**1.****Romanowsky stain** **2. Pearls Stain**

Question 33

Describe the bone marrow

Answer 33

* Cellularity alters throughout life * Normal adult will have 50:50 haemopoetic cells to fat * In a healthy individual myeloid WBC precursors exceed number of RBC precursors 3:1- varies with disease- **M/E ratio**

Question 34

M/E Ratio is increased, normal and reduced in these conditions

Answer 34

Question 35

What can fluorescence flow cytometry be used for?

Answer 35

To identify blood and bone marrow cells according to the presence of CD molecules (glycoprotein's) on the cells surface or in the cytoplasm.

Question 36

What are the uses of fluorescence flow cytometry?

Answer 36

–Panels of markers to confirm diagnosis of malignancies (AML/CLL) –CD34 counts before marrow harvest –Minimal residual disease detection.