"Microscopic Anatomy Bone Marrow Ira Ames" GABY Flashcards Preview

Unit 6 > "Microscopic Anatomy Bone Marrow Ira Ames" GABY > Flashcards

Flashcards in "Microscopic Anatomy Bone Marrow Ira Ames" GABY Deck (45)
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1
Q

Romanovsky Type Blood Stain*

A

Basic (+ or cationic)

  • methylene blue ( RNA )
  • azure B ( DNA & GAGs )

Acidic (- or anionic)
-eosin ( proteins )

2
Q

Variations on Romanovsky Type Blood Stain

A

Wright’s
Giemsa
May-Grunwald

3
Q

Hematopoiesis

A

continuous production of blood cells

4
Q

Hematopoietic organs

A

Bone marrow:
rbcs
granulocytes
monocytes

Lymphoid organs:
lymphocytes

5
Q

Monophyletic theory of hematopoiesis

A

All blood cells are derived from a common pluripotential stem cell (hematopoietic stem cell)

6
Q

Granulopoiesis

A

development of granulocytes
neutrophils
eosinophils
basophils

7
Q

Blast (precursor cell)

A

Large cell (10-15micro)
Large euchromatic nucleus
High nucleocytoplasmic ratio Heavenly blue cytoplasm
No cytoplasmic granules

8
Q

Neutrophil Differentiation

A
Condensation of nuclear chromatin
  -(disappearance of nucleoli)
Lobulation of nucleus
Appearance of cytoplasmic granules 
  -(primary & secondary)
Decrease in cytoplasmic basophilia
9
Q

Under normal conditions blasts, n. promyelocytes, n. myelocytes, and n. metamyelocytes can only be observed in bone marrow

A

True

10
Q

Where are band cells and mature neutrophils seen?

A

In normal peripheral blood

11
Q

Neutrophilic promyelocyte

A

same size as blast

spherical nucleus

more condensed chromatin

*azurophilic granules

12
Q

Azurophilic granules are ___

A

primary lysosomes

*they contain hydrolytic enzymes

13
Q

Neutrophilic myelocyte

A

round-oval nucleus

more heterochromatic

no longer makes azurophylic granules

appearance of specific granules

color of cytoplasm shifts from heavenly blue to salmon pink

14
Q

What do lysozymes and lactoferrin in neutrophil specific granules do?

A

Lysozyme: hydrolyzes glycosides in bacterial cell wall

Lactoferrin: binds iron

Together they kill bacterial cells

15
Q

Neutrophilic metamyelocyte

A

can no longer undergo mitosis

kidney-shaped nucleus (beginning of lobulation)

more condensed chromatin

numerous specific granules

few azurophilic granules

salmon-pink cytoplasm

16
Q

When can we say the metamyelocyte has differentiated into a band?

A

When the indentation exceeds 1⁄2 the diameter of the round nucleus

17
Q

Neutrophilic band

A

curved rod shaped nucleus

more condensed chromatin

cytoplasm just like mature neutrophil

can be observed in normal peripheral blood (1-5% of wbcs)

18
Q

What can the % of bands in peripheral blood provide information about?

A

They provide a rough indication of the rate of neutrophil production in your patient

19
Q

What does a shift to the left mean?

A

Increase in the % of bands in pb indicates that stress is being placed on the bone marrow to produce more neutrophils

20
Q

When can we say that the band has differentiated into a mature neutrophil?

A

When the segments between lobes have become thin heterochromatic filaments

21
Q

What is the life span of neutrophils?

A

15-20 days

9-14 days in bone marrow
1 day in peripheral blood
5 days in surrounding tissue

22
Q

What are the two types of diapedesis?

A

Paracellular (between endothelial cells)

Transcellular (through endothelial cells)

23
Q

Do eosinophils and basophils go through the same sequence of events during their maturation?

A

It is believed so and that the kinetics of the process is about the same

24
Q

What does red bone marrow consist of?

A

small blood vessels
discontinuous sinusoids
hematopoietic cords

25
Q

Where is red bone marrow found?

A
sternum
vertebrae
ribs
clavicles
pelvis
skull
26
Q

Where is there more adipose tissue, red of yellow bone marrow?

A

Yellow

27
Q

What is the function of yellow bone marrow?

A

To store energy

To serve as hematopoietic tissue reserve

28
Q

Hemopoietic stem cell niche

A

An interactive structural unit that nurtures stem cells and facilitates their activity

29
Q

What can we find in HSC niche?

A

Osteoclasts: create spaces in spongy bone surface

Osteoblasts: play a role in the localization of stem cells, and they support hematopoiesis

Other cells that may be involved: endothelial cells, pericytes, bone marrow macrophages (osteomacs)

Important ecm proteins:
fibronectin, laminin, agrin

30
Q

Importance of the hematopoietic stem cell niche

A

Hematopoietic stem cells are not randomly distributed in bone marrow

They live in specific microenvironments called stem cell niches

Interaction of the stem cells with the elements of the stem cell niche (cellular & ecm) is critical

Alterations to the hematopoietic stem cell niche can lead to myeloproliferative disease,
that is a preleukemic condition

31
Q

Erythrocyte differentiation

A

Decrease in cell volume

Decrease in nuclear diameter

Increase in heterochromatin

Disappearance of nucleoli

Loss of nucleus

Decrease in cytoplasmic basophilia

Increase in cytoplasmic eosinophilia (due to accumulation of Hb)

32
Q

Basophilic erythroblast (BEB)

A

First recognizable stage in erythropoiesis

Smaller than a blast

Checkerboard nucleus

Loss of nucleolus

Navy blue cytoplasm (due to increase in free ribosomes which participate in production of Hb)

Capable of cell division (1-2 times)

33
Q

Polychromatophils are capable of dividing ___ times

A

3-4

34
Q

Normoblast (NB)

A

smaller cell

smaller heterochromatic nucleus

slightly polychromatophilic cytoplasm

terminal cell: can no longer undergo mitosis

35
Q

What is the fate of normoblasts?

A
  1. 80% become reticulocytes

2. 20% become orthochromatic erythroblasts

36
Q

Maturation time for RBCs

A

Total time: 8-9 days

1-2 days as a basophilic erythrocyte

3 days as a polychromatophil

3 days for normoblast to reticulocyte transition

1 day for reticulocyte to RBC transition

37
Q

Orthochromatic erythroblast (OCE)

A

Uses up its residual RNA before it extrudes its nucleus

Resembles a nucleated rbc

*not present in normal peripheral blood

38
Q

Erythropoietin

A

Glycoprotein hormone

Produced in the kidney cortex
(probably by endothelial cells of the peritubular capillary plexus)

Increases rate of mitosis (in blasts, basophilic erythroblasts and polychromatophils)

Increases RNA synthesis in developing rbcs (especially mRNA for hemoglobin)

Attenuates the degree of brain damage after stroke

Synthesis is stimulated by hypoxia

39
Q

Erythroblastic island

A

Developing rbcs cluster around reticular cells in bone marrow

Reticular cells phagocytose extruded nuclei

40
Q

Plasma cell (in marrow smear)

A

basophilic cytoplasm
negative image of Golgi
acentrically placed nucleus
“clock face” chromatin

41
Q

Megakaryocyte Differentiation

A

Cell enlargement

Lobulation of nucleus

Increase in level of ploidy ( 32-64n )

Shift in cytoplasmic basophilia to acidophilia

Accumulation of azurophilic cytoplasmic granules

Formation of platelet demarcation channels

42
Q

Proplatelet model of platelet production

A
  1. Extension of thick pseudopods
  2. Formation of long extensions (proplatelets)
  3. Platelets are released from ends of proplatelets
43
Q

Megakaryocytes

A

Megakaryocytes lie just outside of the discontinuous sinusoids

They release platelets into the lumen of the sinusoids

Platelets circulate for about 10 days

They are then destroyed within the spleen and liver

They contain a functional repertoire of mRNAs

Platelets may be able to produce functional progeny??

44
Q

Lymphocyte Differentiation

A

Decrease in cell size Condensation of chromatin
Disappearance of nucleoli
Acquisition of cell surface receptors

  • Some cells migrate to the thymus (T lymphs)
  • Some cells begin differentiation in the bone marrow (B lymphs)
45
Q

Monocytes

A

bone marrow (2-3 days)

circulation (1-2 days)

tissues (as macrophages) (1-3 months)

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