Bone Marrow and Hematopoiesis Flashcards Preview

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Flashcards in Bone Marrow and Hematopoiesis Deck (32)
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1
Q

In what stage of hemopoiesis does blood form in the mesenchyme and yolk sac; 2nd and 3rd week of gestation

A

Mesoblastic (yolk sac phase)

2
Q

The yolk sac contains precursors of both … and… cells

A

blood and germ cells

3
Q

In what stage of hemopoiesis does blood form in the liver and spleen; 6th week of gestation

A

haptic

4
Q

In what stage of hemopoiesis does blood form in bone marrow (and other lymphatic tissues); 4th and 5th month

A

myeloid phase

5
Q

After birth hemopoiesis only occurs where?

A

red bone marrow and lymphatic tissues

6
Q

If the bone marrow is damaged in an adult, what organs can resume blood cell formation

A

spleen and liver

7
Q

Under adverse conditions such as … or …, yellow marrow reverts to red marrow.

A

hypoxia or severe loss of blood

8
Q

Barrier between the blood and the hematopoietic tissue. Its wall consists of three layers

A

Vascular Sinuses

9
Q

The continuous endothelium layer of the vascular sinuses is composed of simple squamous cells joined together by … therefore no mature cells pass between the endothelial cells, but through them (Transcellular)

A

junctional complexes

10
Q

Cover most of the outer surface of vascular sinus endothelium; synthesize the reticular fibers in marrow; produce cytokines for the proliferation and maturation of blood cell precursors; make up the adipose cells of yellow marrow

A

adventitial reticular cells

11
Q

adipocytes in yellow marrow are simulated by …

A

glucocorticoids

12
Q

Where do blood cells develop?

A

Hematopoietic Cords

13
Q

Houses the red blood producing cells; usually macrophages are found here

A

erythroid compartment

14
Q

Usually macrophages are found in the center of erythroid cell clusters known as …

A

erythroblastic islets

15
Q

All blood cell types originate from one pluripotential stem cell

A

Monophylectic Theory

16
Q

The pluripotential stem cell (PPSC) produces two cell lineages … and … which make up the multi potential stem cell lineages

A

lymphoid and myeloid cell

17
Q

Precursor cells (CFUs) are also known as …

A

blast cells i.e. myeloblasts, erythroblasts, etc.

18
Q

The first recognizable cell in the series of erythrocyte development is the …

A

Pronormoblast (Proerythroblast)

19
Q

Proerythroblasts have a basophilic cytoplasm due to the presence of ribosomes actively synthesizing …

A

hemoglobin

20
Q

In what stage of erythropoiesis does the nucleolus become no longer visible?

A

basophilic normoblast

21
Q

In what stage of erythropoiesis is the Hb content of the cytoplasm increases. Hb is acidophilic making the cytoplasm stain both acidophilic and basophilic

A

polychromatophilic normoblast

22
Q

Reticulocytes leave the bone marrow through the …

A

sinuses

23
Q

Iron bound to heme is released and stored in the spleen as … for reuse

A

hemosiderin or ferritin

24
Q

Heme is partially degraded to … and eventually excreted via the gallbladder in stool or in the urine

A

bilirubin

25
Q

The differentiation of stem cells into neutrophils (PMNs), eosinophils and basophils

A

Granulopoiesis

26
Q

The first recognizable precursors of granulocytes; no visible granules

A

Myeloblasts

27
Q

This stage is characterized by the appearance of azurophilic granules, which are produced only during this stage

A

Promyelocyte

28
Q

The 3 granulocytes can now be distinguished from each other based on the apperance of the specific granules

A

Myelocyte

29
Q

Kidney bean-shaped nucleus for all three lineages in this stage

A

metamyelocyte

30
Q

In this stage the nuclei assume a curved shape; most obvious in the neutrophil line

A

Band cells

31
Q

The appearance of … in the blood is important clinically because it indicates an increase in granulopoiesis in response to injury such as infections; known as a shift to the left

A

Band cells

32
Q

refers to a low platelet count

A

Thrombocytopenia