Hematopoeisis

Question 1

During which week do blood precursors arise and from where?

Answer 1

1) 3rd-4th week

2) yolk sac

Question 2

During which week of gestation do the liver and spleen become temporary hematopoetic tissues?

Answer 2

5th week

Question 3

During the 5th month of gestation what becomes the most important hematopoietic tissue?

Answer 3

bone marrow

Question 4

When looking at the Red bone marrow what is the 3D meshwork of reticular fibers containing hematopoeitic cells, macrophages and few adipocytes called?

Answer 4

the Stroma. (remember she said that was the “land” and the sinusoids was the “sea”)

Question 5

In attempt to stimulate development of blood cells within the stroma the reticular cells will secrete what two things?

Answer 5

1) reticular fibers

2) cytokines

Question 6

What are the two lineages that arise from the pluripotent stem cell?

Answer 6

1) Myeloid cells (CFU GEMM)

2) Lymphocytes (CFU L)

Question 7

In attempt to enter circulation from the bone marrow the RBCs, WBCs and platelets have to go through leaky capillaries called what?

Answer 7

Sinusoids ( The “SEA”)

Question 8

Which type of stem cell give rise to myeloid cells in red bone marrow?

Answer 8

Pluripotent stem cell ( remember these can differentiate into any type of blood cell as well as renew themselves)

Question 9

The 4 types of myeloid cells are what?

Answer 9

1) Granulocytes
2) erythrocytes
3) megakaryocyte
4) monocyte

Question 10

Which type of stem cell give rise to the lymphocytes in the bone marrow?

Answer 10

Pluripotent stem cell

Question 11

During the development of mature red blood cells the proerythoblast will stain which color and why?

Answer 11

blue, it is strongly basophilic

Question 12

During which stage of the development of the RBC does the cell lose its nucleus and exits the bone marrow and pass into the blood stream?

Answer 12

reticulocyte

Question 13

All the discarded erythrocyte nuclei is phagocytosed by what?

Answer 13

Nurse cell

Question 14

In response to a decreased blood oxygen level what is secreted by the kidney?

Answer 14

erythropoietin

Question 15

Erythropoeitin is important for the promotion of what in the Red bone marrow in order to increase the blood oxygen level?

Answer 15

erythropoiesis

Question 16

What kind of receptors does EPO bind to promote the production of RBCs?

Answer 16

CFU-E receptors

Question 17

During longterm illegal doping of EPO the level of Hematocrit increases, this can be detrimental to the body for 2 reasons . Explain those two reasons.

Answer 17

1) the heart has to work a lot harder and faster to push the increase amount of RBCs
2) Clotting in the legs can occur due to increase thickness of the blood

Question 18

A patient with an increase in immature neutrophils (a large number of band cells in the blood) is said to be experiencing a shift to the left, this shift is indicative of what?

Answer 18

bacterial infection.

Question 19

An anemic patient visits a clinic, she reports she is prone to infection and does not know why. Lab results come back and show there are large numbers of immature WBCs being released into the blood. Further investigation shows there seems to be malignant clones of leukocyte precursors that occur in certain tissues. What is her diagnosis and what tissue will you see these leukocyte clones?

Answer 19

1) Leukemia

2) Lymphoid tissue and bone marrow

Question 20

Monocytes and Neutrophils are derived from which CFU category?

Answer 20

CFU-GM

Question 21

Promonocyte will give rise to what?

Answer 21

Monocyte then Macrophages once it enters the CT

Question 22

How do RBCs enter the bloodstream?

Answer 22

By a pressure gradient within the wall. (Veins create suction from the stroma into the capillaries)

Question 23

How do leukocytes enter the blood stream?

Answer 23

Diapedesis

Question 24

How do Megakaryocytes from platelets?

Answer 24

Form thin processes that cross the wall of the sinusoids and fragment their tips to liberate platelets