Hematopoiesis

Question 1

is the process of blood cell production,
differentiation, and development.

Answer 1

Hematopoiesis

Question 2

are the foundation of the
adult hematopoietic system.

Answer 2

Hematopoietic stem cells (HSCs)

Question 3

These cells are present in the first few hours after an ovum is fertilized. Are the most versatile type of stem cell, can develop into any human cell type, including development from embryo into fetus.

Answer 3

Totipotential stem cells

Question 4

 These cells are present several days after fertilization.
 can develop into any cell type, except they cannot develop into a fetus.

Answer 4

Pluripotent stem cells

Question 5

 These cells are derived from pluripotent stem cells.
 They can be found in adults, but they are limited to specific types of cells to form tissues.
o For example, bone marrow stem cells can
produce all types of blood cells, bone cartilage,
and adipose (fat) cells.

Answer 5

Multipotential stem cells

Question 6

DEVELOPMENT OF THE HEMATOPOIETIC
SYSTEM (3 DEFINED PERIODS)

Answer 6

Mesoblastic period
Hepatic Phase
Medullary (Myeloid) Phase

Question 7

Early in embryonic development, cells from the mesoderm
migrate to the

Answer 7

Yolk sac

Question 8

Some of these cells form___
in the central cavity of the yolk sac, while the
others (_____) surround the cavity of the
yolk sac and eventually form blood vessels.

Answer 8

primitive erythroblasts
angioblasts

Question 9

These primitive but transient yolk sac erythroblasts are
important in early embryogenesis to produce hemoglobin

Answer 9

(Gower-1, Gower-2, and Portland).

Question 10

was the major
site of adult blood formation in the embryo.

Answer 10

Yolk sac

Question 11

Hematopoiesis during this phase occurs extravascularly,
with the liver remaining the major site of hematopoiesis
during the second trimester of fetal life.

Answer 11

Hepatic phase

Question 12

remaining the major site of hematopoiesis
during the second trimester of fetal life.

Answer 12

Liver

Question 13

Hematopoiesis in the fetal liver reaches its peak by the __
month of fetal development, then gradually declines after
the __ month, retaining minimal activity until 1 to 2 weeks
after birth.

Answer 13

3rd 6th

Question 14

The developing ______
contribute to the hematopoietic process d

Answer 14

spleen, kidney, thymus, and lymph nodes

Question 15

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

Answer 15

Thymus

Question 16

Produce B cells

Answer 16

Spleen and kidney

Question 17

Production of megakaryocytes also begins during the

Answer 17

Hepatic phase

Question 18

During the hepatic phase, detectable levels of adult
___ may be present.

Answer 18

hemoglobin (Hb A)

Question 19

Prior to the fifth month of fetal development, hematopoiesis
begins in the

Answer 19

bone marrow cavity.

Question 20

In medullary phase thus transition is called

Answer 20

Medullary hematopoiesis

Question 21

is considered to be a special kind
of humoral factor or protein that is necessary in the
production of RBCs.

Answer 21

Hematopoietin

Question 22

During the myeloid phase, HSCs and mesenchymal cells
migrate into the _____
BOOK: And they differentiate into ___

Answer 22

core of the bone
skeletal and
hematopoietic blood cells.

Question 23

myeloid-to-erythroid ratio gradually approaches __ (adult
levels) by 21 weeks of gestation.

Answer 23

3:1

Question 24

By the end of 24 weeks’ gestation, the ______
becomes the primary site of hematopoiesis.

Answer 24

Bone marrow

Question 25

Measurable levels of can be detected:

Answer 25

 erythropoietin (EPO),
 granulocyte colony stimulating factor (G-
CSF),
 granulocyte-macrophage colony
stimulating factor (GM-CSF),
 hemoglobin F and A