Blood & Bone Marrow VM Flashcards
What criteria need to be met to produce functional erythrocytes?
- Cell must be small
- Must contain abundant hemoglobin
- Must be biconcave
What are the general trends of change seen in maturing erythrocytes?
Grow smaller, more eosinophilic, and with less and less prominent nucleus.
Describe the sequence of cells that result in a mature erythrocyte.
At what point does it leave the bone marrow?
Proerythroblast > Basophilic erythroblast > Polychromatophilic erythroblast > Orthochromatophilic erythroblast > Reticulocyte > Erythrocyte.
Reticulocytes may leave the bone marrow and mature in the peripheral blood.
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?
Erythrocytes become microcytic.
Reticulocytes (first point to be anucleate)
mRNA production attenuates, and eosinophilic proteins predominate.
What are the general trends of change seen in maturation of granulocytes?
Cells become smaller, nuclei generally fragment or become lobular. Color and granules depend on the identity of the mature cell.
Describe the sequence of cells that result in mature granulocytes.
Myeloblast > Promyelocyte > Myelocyte > Metamyelocyte > Band/stab cell > (neutrophil/eosinophil/basophil).
Where are monocytes easy to distinguish?
Which lymphocyte can be seen in the bone marrow? What is it called?
In the peripheral blood; often obscured in bone marrow.
B-lymphocyte precursors, known as hematogones.
What is the most common site of bone marrow biopsy?
What should be found in these biopsies?
Posterior iliac crest.
Trabecular bone, adipose tissue, and hematopoietic elements.
Define bone marrrow cellularity.
How can it be (roughly) estimated?
The percentage of hematopoietic cells compared to fat.
Tends to decrease with age, try 100 - (age in years)
Identify:
Promyeloblast. Note the large size, euchromatin, and thin rim of light blue cytoplasm.
Identify:
Proerythroblast. Note the large size and prominent, central nucleus. Note also the basophilicity.
Identify:
Band / Stab cell. Note the granularity, somewhat large size, and lobular but not fragmented nuclei.
Identify:
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…
Identify:
Megakaryocyte. Note the massive size and nucleus, as well as the budding platelets.
Identify: (both arrows)
Bone marrow biopsy; fat arrow points to trabecular bone, thin arrow points to adipocytes & hematopoietic elements.
Identify: (DIFFICULT)
(polychromatophilic) erythroblast. Note the medium size (1.5x an RBC), central nucleus, condensed chromatin, and weakly basophilic staining.
Define:
- Anisocytosis
- Poikilocytosis
- variation in cell size
- variation in cell shape
Identify the disease state seen in the image
SCD
Are nuclei present in mature healthy RBCs?
What is the approximate lifespan on an RBC?
No
~120 days
Name the immediate precursor stage to a mature erythrocyte
describe their appearance compared to RBCs
reticulocyte
usually indistinguishable from mature erythrocytes, but they may be identified with cresyl blue stain, which will stain blue any residual polyribosomes
What is the average diameter of an RBC?
~7um
Why might you observe a drumstick-like nuclear appendage on an otherwise normal neutrophil?
The blood smear is from a female - the nuclear appendage represents the Barr Body (inactivated X chromosome)
Do neutrophils have granules? If yes, what color would they stain?
Yes. The do not stain.
Describe the specific and non-specific granules of neutrophils
- specific (primary) granules
- lysosomes
- contain acid hydrolases, lysozyme, and other enzymes
- non-specific (secondary) granules
- contain alkaline phosphatase, amino peptidase, collagenase, and other enzymes
Name:
10-14um, eosinophilic granules, bi-lobed nucleus
EM: elliptical granules with dense crystalloid core
eosinophil
What is (arguably) the most important substance found in eosinophil granules for fighting helminthic infection?
Major Basic Protein (MBP)
Under normal conditions, what is (usually) the rarest of the three major granulocytes?
basophils
Name:
small granulocyte (8-10um), dark-purple staining specific granules, mostly-obscured nucleus
basophil
What is the response of a basophil to histamine?
becomes more sensitive to degranulation
Describe the nuclear morphology of monocytes
How big are monocytes?
horseshoe or S-shaped
15-20um
Describe the relationship between monocytes and macrophages
When monocytes move into peripheral tissues, they differentiate into macrophages. Many types of macrophage exist depending on tissue type
Name the location of the following resident macrophage types:
- Kupffer cell
- Microglial cell
- Alveolar macrophage
- Histiocyte
- Liver
- CNS
- Lung
- Connective tissue
Under normal conditions, the majority of lymphocytes are what type?
Describe their nuclear/cytoplasmic (N/C) ratio
T-cells
High N/C ratio (nucleus takes up nearly the whole cell)
Megakaryocytes produce what?
platelets
How many nuclei to platelets have?
Megakaryocytes?
Zero
One (large)
