Stages Of Hematopoiesis

Question 1

Capable of self-renewal and directed differentiation into all required cell lineages

Answer 1

Hematopoietic Stem Cell (HSC)

Question 2

Sequential distribution of cells

Answer 2

Aorta-gonad-mesonephros (AGM)
Mesoblastic phase
Hepatic phase (fetal liver)
Medullary phase (bone marrow)

Question 3

Begins at 19th day of gestation

Answer 3

Mesoblastic phase

Question 4

Chief site of the mesoblastic phase

Answer 4

Yolk sac

Question 5

Central cavity of the yolk sac and important in early embryogenesis to produce hemoglobin (delivery of oxygen)

Answer 5

Primitive erythroblasts

Question 6

Surrounds cavity of yolk sac and form blood vessels

Answer 6

Angioblasts

Question 7

Where does the mesoblastic phase occurs? Intravascularly or extravascularly?

Answer 7

Intravascularly (within developing blood vessels)

Question 8

Cells of mesodermal origin migrate to the AGM region and give rise to _____________ for definitive or permanent adult hematopoiesis

Answer 8

Hematopoietic stem cell

Question 9

Previously considered only site of definitive hematopoiesis during embryonic development

Answer 9

AGM region

Question 10

Major site of adult blood formation in the embryo

Answer 10

Yolk sac

Question 11

Separated from human umbilical cord blood could generate hematopoietic as well as endothelial cells in vitro

Answer 11

Flk1-HSCs

Question 12

Embryonic hemoglobins that are present only in mesoblastic phase

Answer 12

Gower I
Gower II
Portland

Question 13

A mixture of heme and globin

Answer 13

Hemoglobin

Question 14

Begins at 5 to 7 gestational weeks or 3rd month of pregnancy

Answer 14

Hepatic phase

Question 15

Chief site of hepatic phase

Answer 15

Liver

Question 16

Where does the hepatic phase occurs? intravascularly or extravascularly?

Answer 16

Extravascular

Question 17

Predominant hemoglobin in the hepatic phase

Answer 17

Fetal hemoglobin (Hb F)

Question 18

Characterized by recognizable clusters of developing erythroblasts, granulocytes, and monocytes

Answer 18

Hepatic phase

Question 19

During the hepatic phase, developing erythroblasts signals the beginning of definitive hematopoiesis with a decline in primitive hematopoiesis of the yolk sac, where the ______ begin to appear

Answer 19

Lymphoid cells

Question 20

Production of megakaryocytes

Answer 20

Hepatic phase

Question 21

First fully developed organ in the fetus, major site of T cell production

Answer 21

Thymus

Question 22

Organs that produce B cells

Answer 22

Liver and Spleen

Question 23

Adults predominant hemoglobin

Answer 23

Hb A1 - 95%
Hb A2 - 2-3%
Hb F - 1-2%

Question 24

Begins on the 5th month of gestation

Answer 24

Medullary phase/Myeloid phase

Question 25

Chief site of the medullary phase

Answer 25

Bone marrow

Question 26

End of ____ weeks of gestation, the bone marrow becomes the primary site of hematopoiesis

Answer 26

24th weeks

Question 27

During medullary phase, the _____ and ____ migrate into the core of the bone

Answer 27

HSCs and mesenchymal cells

Question 28

Adult hematopoietic tissue is located in

Answer 28

Bone marrow
Lymph nodes
Spleen
Liver
Thymus

Question 29

The bone marrow contains developing

Answer 29

Erythroid
Myeloid
Megakaryocytic
Lymphoid cells

Question 30

Primary lymphoid tissue

Answer 30

Bone marrow and Thymus

Question 31

Secondary Lymphoid Tissue

Answer 31

‘Spleen, Lymph nodes and Mucosa-associated lymphoid tissue