Blood & Bone Marrow VM

Question 1

What criteria need to be met to produce functional erythrocytes?

Answer 1

1. Cell must be small
2. Must contain abundant hemoglobin
3. Must be biconcave

Question 2

What are the general trends of change seen in maturing erythrocytes?

Answer 2

Grow smaller, more eosinophilic, and with less and less prominent nucleus.

Question 3

Describe the sequence of cells that result in a mature erythrocyte.

At what point does it leave the bone marrow?

Answer 3

Proerythroblast > Basophilic erythroblast > Polychromatophilic erythroblast > Orthochromatophilic erythroblast > Reticulocyte > Erythrocyte.

Reticulocytes may leave the bone marrow and mature in the peripheral blood.

Question 4

How might iron defiency affect the morphology of erythrocytes?

At which stage of development do the cells in the erythropoietic series lose their mitotic ability?

Why is the cytoplasm changing color as the cells in the erythropoietic series differentiate?

Answer 4

Erythrocytes become microcytic.

Reticulocytes (first point to be anucleate)

mRNA production attenuates, and eosinophilic proteins predominate.

Question 5

What are the general trends of change seen in maturation of granulocytes?

Answer 5

Cells become smaller, nuclei generally fragment or become lobular. Color and granules depend on the identity of the mature cell.

Question 6

Describe the sequence of cells that result in mature granulocytes.

Answer 6

Myeloblast > Promyelocyte > Myelocyte > Metamyelocyte > Band/stab cell > (neutrophil/eosinophil/basophil).

Question 7

Where are monocytes easy to distinguish?

Which lymphocyte can be seen in the bone marrow? What is it called?

Answer 7

In the peripheral blood; often obscured in bone marrow.

B-lymphocyte precursors, known as hematogones.

Question 8

What is the most common site of bone marrow biopsy?

What should be found in these biopsies?

Answer 8

Posterior iliac crest.

Trabecular bone, adipose tissue, and hematopoietic elements.

Question 9

Define bone marrrow cellularity.

How can it be (roughly) estimated?

Answer 9

The percentage of hematopoietic cells compared to fat.

Tends to decrease with age, try 100 - (age in years)

Question 10

Identify:

Answer 10

Promyeloblast. Note the large size, euchromatin, and thin rim of light blue cytoplasm.

Question 11

Identify:

Answer 11

Proerythroblast. Note the large size and prominent, central nucleus. Note also the basophilicity.

Question 12

Identify:

Answer 12

Band / Stab cell. Note the granularity, somewhat large size, and lobular but not fragmented nuclei.

Question 13

Identify:

Answer 13

Hematogones. Note the extremely high N:C ratio, moderately increased size, and euchromatin.

Note: This is not a normal smear! Hematogones are never this tightly clustered outside of cancers…

Question 14

Identify:

Answer 14

Megakaryocyte. Note the massive size and nucleus, as well as the budding platelets.

Question 15

Identify: (both arrows)

Answer 15

Bone marrow biopsy; fat arrow points to trabecular bone, thin arrow points to adipocytes & hematopoietic elements.

Question 16

Identify: (DIFFICULT)

Answer 16

(polychromatophilic) erythroblast. Note the medium size (1.5x an RBC), central nucleus, condensed chromatin, and weakly basophilic staining.

Question 17

Define:

1. Anisocytosis
2. Poikilocytosis

Answer 17

1. variation in cell size
2. variation in cell shape

Question 18

Identify the disease state seen in the image

Answer 18

SCD

Question 19

Are nuclei present in mature healthy RBCs?

What is the approximate lifespan on an RBC?

Answer 19

No

~120 days

Question 20

Name the immediate precursor stage to a mature erythrocyte

describe their appearance compared to RBCs

Answer 20

reticulocyte

usually indistinguishable from mature erythrocytes, but they may be identified with cresyl blue stain, which will stain blue any residual polyribosomes

Question 21

What is the average diameter of an RBC?

Answer 21

~7um

Question 22

Why might you observe a drumstick-like nuclear appendage on an otherwise normal neutrophil?

Answer 22

The blood smear is from a female - the nuclear appendage represents the Barr Body (inactivated X chromosome)

Question 23

Do neutrophils have granules? If yes, what color would they stain?

Answer 23

Yes. The do not stain.

Question 24

Describe the specific and non-specific granules of neutrophils

Answer 24

• specific (primary) granules
  
  • lysosomes
  • contain acid hydrolases, lysozyme, and other enzymes
• non-specific (secondary) granules
  
  • contain alkaline phosphatase, amino peptidase, collagenase, and other enzymes

Question 25

Name:

10-14um, eosinophilic granules, bi-lobed nucleus

EM: elliptical granules with dense crystalloid core

Answer 25

eosinophil

Question 26

What is (arguably) the most important substance found in eosinophil granules for fighting helminthic infection?

Answer 26

Major Basic Protein (MBP)

Question 27

Under normal conditions, what is (usually) the rarest of the three major granulocytes?

Answer 27

basophils

Question 28

Name:

small granulocyte (8-10um), dark-purple staining specific granules, mostly-obscured nucleus

Answer 28

basophil

Question 29

What is the response of a basophil to histamine?

Answer 29

becomes more sensitive to degranulation

Question 30

Describe the nuclear morphology of monocytes

How big are monocytes?

Answer 30

horseshoe or S-shaped

15-20um

Question 31

Describe the relationship between monocytes and macrophages

Answer 31

When monocytes move into peripheral tissues, they differentiate into macrophages. Many types of macrophage exist depending on tissue type

Question 32

Name the location of the following resident macrophage types:

• Kupffer cell
• Microglial cell
• Alveolar macrophage
• Histiocyte

Answer 32

• Liver
• CNS
• Lung
• Connective tissue

Question 33

Under normal conditions, the majority of lymphocytes are what type?

Describe their nuclear/cytoplasmic (N/C) ratio

Answer 33

T-cells

High N/C ratio (nucleus takes up nearly the whole cell)

Question 34

Megakaryocytes produce what?

Answer 34

platelets

Question 35

How many nuclei to platelets have?

Megakaryocytes?

Answer 35

Zero

One (large)