Hematopoiesis

Question 1

Hematopoiesis

Answer 1

Continuous replacement of RBCs

Question 2

Where is the prenatal site for Hematopoiesis?

Answer 2

Yolk sac, liver, spleen, lymph node, bone marrow

Question 3

Where is the postnatal site for Hematopoiesis?

Answer 3

Bone marrow of all bones in young animals
Sternum, vertebrae, ribs, skull, pelvis and epiphyses of long bones in adult animals

Question 4

Stem cells involved in hematopoiesis

Answer 4

Pluripotent
Multipotent (lymphoid and myeloid)
Unipotent

Question 5

Where do all blood cells develop from?

Answer 5

A pluripotent stem cell in the bone marrow

Question 6

What do pluripotent stem cells gives rise to?

Answer 6

Myeloid multi-potential stem cell and Lymphoid- multi potential stem cell

Question 7

What do myeloid multi-potential stem cell give rise to?

Answer 7

All blood cells except lymphocytes

Question 8

What do lymphoid multi-potential stem cells give rise to?

Answer 8

Lymphocytes

Question 9

What do B lymphocytes do? (Lymphopoiesis)

Answer 9

Differentiate from precursor cells in the bone marrow
Acquire B cell-specific surface makers
(Humoral activity)

Question 10

What do T cells do? (Lymphopoiesis)

Answer 10

Migrate into the thymus where they acquire T cell-specific surface makers
Cell mediated

Question 11

Diapedesis

Answer 11

Leukocytes migrating from bone marrow into the sinusoid

Question 12

Stages in development of RBC

Answer 12

1.Reticulum (CFU-E)
2. Rubriblasts
a. decrease cell size
b. Increase Hb synthesis
3. Prorubicyte
a. Loss of cytoplasmic granules
b. Increase in cytoplasmic eosinophilia
4. Rubicyte (normoblast)
a. Increase in condensation of chromatin nucleus (loss
of nucleus
5. Metarubricyte
—- no mitosis—–
6. Reticulocyte
7. Erythrocyte

Question 13

What does CFU stand for?

Answer 13

Colony forming unit

Question 14

Erythropoietin

Answer 14

Hormone secreted by the kidneys that increases RBC production rate, in response to oxygen levels falling in tissues.

Question 15

Reticulocytes in ruminants

Answer 15

No reticulocytes in healthy animals
In anemic animals

Question 16

Reticulocytes in dogs and cats

Answer 16

1-2% in blood of healthy animals
Increase in number in anemic animals

Question 17

What is the increase of reticulocytes during anemia?

Answer 17

Polychromasia

Question 18

Staining of reticulocytes

Answer 18

Slides with basic dyes because they contain polyribosomes (basophilic strands)
EX: Methylene blue

Question 19

Stages in the development of granulocytes

Answer 19

Seen in goodnotes

Question 20

Left shift

Answer 20

The body responding to an inflammatory stimulus
Bone marrow releasing more immature forms of neutrophils (band cells)

Question 21

Regenerative left shift

Answer 21

Leukocyte count elevated with neutrophilia and high numbers of mature neutrophils than immature

Question 22

Degenerative Left Shift

Answer 22

Demand for neutrophils increase, bone marrow stores depleted, marrow will release mainly immature neutrophils

Question 23

What are the affects of degenerative left shift?

Answer 23

Leukocyte count will drop (leukopenia)
Mature neutropenia will develop
Number of immature neutrophils will be greater than the number of mature

Question 24

Proliferation of hematopoietic stem cells and progenitor cells

Answer 24

Cannot occur spontaneously
Requires the presence of specific hematopoietic growth factors (HGFs, hematopoietic cytokines)

Question 25

What does erythropoietin do?

Answer 25

Prolongs the survival of erythroid precursors
Shortens time between cell divisions
Increases number of cell produced from individual precursors
Stimulates Hb synthesis in dividing erythroid cells

Question 26

What is the source of erythropoietin?

Answer 26

Peritubular interstitial cells located in the inner cortex and outer medulla of kidney (85-90%)
Specific hepatocytes and Ito cells in liver (10-15%)

Question 27

Thrombopoietin

Answer 27

Regulates development of megakaryocytes from hematopoietic stem cells and level of platelets in the blood

Question 28

Where is thrombopoietin produced?

Answer 28

Liver

Question 29

Granulocyte Colony-Stimulating

Answer 29

Stimulates growth and differentiation of neutrophils
Produced by monocytes, macrophages, fibroblasts, stromal cells, endothelial cells

Question 30

Development of monocytes

Answer 30

1. CFU-G (granulocytes)
2. Monoblast
3. Promonocyte
4. Monocyte (macrophage in the CT)

Question 31

Development of Platelets

Answer 31

1. CFU-MK
2. megakaryocyte
3. Platelets