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
