ICL 1.2: Bone Marrow Flashcards
Are platelets included in the bone marrow differential?
No because they’re evenly spaced throughout
What is normal bone marrow made of?
Hematopoietic tissue and sinusoids that are supported by a network of fibers and cells called stroma
What does hematopoietic tissue do?
Gives rise to all cellular components of the blood
It decreases in amount as we age 1% per year until you get down to 30%
What what is the myeloid:erythroid ratio?
2:1 up to 4:1
Tells us about the relative portions of cells in the marrow
What is the bone marrow stroma made of?
Cells: fibroblasts, macrophages, adipose cells, osteogenetic cells
Fibers: collagen and reticular fibers
Which adult bones normally contain bone marrow?
Flat bones = pelvis
Long bones = femur
Which bone marrow specimen is best for examining individual cell morphology?
Bone marrow aspirate smear
How many RBCs are removed per day?
2x10^11 RBC/day removed
Where are RBCs destroyed?
Spleen
Where are RBCs made during 1st trimester?
Yolk sac
RBC made is called Hb Gower and Hb Portland because there’s zeta chains instead of alpha
Where are RBCs made during 2nd trimester?
Liver
HbF is what’s made
What kind of bone marrow does hematopoiesis occur?
Only in red marrow!
Vertebrae, ribs, sternum, skull, pelvis, proximal femur and humerus
Where is RBC production during 3rd trimester?
Bone marrow
HbA is what’s made
What types of Hb are present at birth?
50-50 HbF and HbA
At 6 months it normal adult levels of HbA (96%) and HbA2 (3%)
What are the growth factors for stem cells?
SCF, c-KIT ligand, Flt3-ligand
What are the growth factors for granulocytes?
GM-CSF
What are the growth factors for eosinophils?
IL-5
What are the growth factors for monocytes?
M-CSF
What are the growth factors for magkaryocytes?
Thrombopoietin
What are growth factors for B cells?
Flt3L
What are the growth factors for T cells?
IL-7
What are the growth factors for NK cells?
IL-15
How is erythropoiesis regulated?
Oxygen deficiency —> erythropoietin production by kidneys —> stimulates RBC production in bone marrow —> causes restored oxygen level
Where does erythropoiesis occur during adulthood?
Bone marrow
What are the stages of erythropoeisis?
- Stem cell
- Pro-erythroblast
- Basophilic erythroblast
- Polychromatophilic erythroblast
- Orthochromatophilic erythroblast
- Reticulocyte
- Mature erythrocytes
Why are granulocytes named the way they are?
They have specific granules
What two features characterize promyelocytes?
Size (large)
Granulation (lots of granules)
In granulocytes, which self stage is the first one to show differentiation?
Promyelocyte stage
Which cell stage in the monocytes series has beautiful tissue paper nuclear folds?
Promonocyte
What stages of lymphocyte development are visible in normal bone marrow?
Lymphoblastic and lymphocyte
