Bone Marrow and Hematopoiesis Flashcards Preview

Histology > Bone Marrow and Hematopoiesis > Flashcards

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

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

Mesoblastic (yolk sac phase)

2

The yolk sac contains precursors of both ... and... cells

blood and germ cells

3

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

haptic

4

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

myeloid phase

5

After birth hemopoiesis only occurs where?

red bone marrow and lymphatic tissues

6

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

spleen and liver

7

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

hypoxia or severe loss of blood

8

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

Vascular Sinuses

9

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)

junctional complexes

10

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

adventitial reticular cells

11

adipocytes in yellow marrow are simulated by ...

glucocorticoids

12

Where do blood cells develop?

Hematopoietic Cords

13

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

erythroid compartment

14

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

erythroblastic islets

15

All blood cell types originate from one pluripotential stem cell

Monophylectic Theory

16

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

lymphoid and myeloid cell

17

Precursor cells (CFUs) are also known as ...

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

18

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

Pronormoblast (Proerythroblast)

19

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

hemoglobin

20

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

basophilic normoblast

21

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

polychromatophilic normoblast

22

Reticulocytes leave the bone marrow through the ...

sinuses

23

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

hemosiderin or ferritin

24

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

bilirubin

25

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

Granulopoiesis

26

The first recognizable precursors of granulocytes; no visible granules

Myeloblasts

27

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

Promyelocyte

28

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

Myelocyte

29

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

metamyelocyte

30

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

Band cells

31

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

Band cells

32

refers to a low platelet count

Thrombocytopenia