Bone Marrow Flashcards
Process of replacing active marrow by fat tissue during development; results in restrictive active marrow sites
Retrogression
1 Stain
Wright stain
- Sternum
- Skull
- Proximal end of large bones
- Vertebrae
- Iliac crest
Hematopoietic sites
Fat cell conversion
yellow marrow
antigen processing of cellular and humoral immunity
Minor function of Bone Marrow
production and proliferation of blood cells
Major function of Bone Marrow
- As part of differential diagnosis workup for infections that manifest clinically as “fevers of unknown origin”
- As part of initial workup of unexplained ↑ or ↓ in RBCs, WBCs, and/or platelets
- In patients with solid malignant tumors
Three main reasons for performing a bone marrow evaluation
Fat droplets
Bone spicules
Very immature hematopoietic cells
Three findings used to verify bone marrow has been obtained
Posterior iliac crest (adults and children)
Sternum (adults)
Vertebrae (in adults)
Tibia (children <1 year old)
Four preferred locations for bone marrow tap (in order of preference)
judged as normal, ↑ (hyperplastic) or ↓ (aplastic/hypoplastic) → ALL evaluated on 10x
Cellularity
reflected in ratio of fat cells to hematopoietic cells (which is normally 1:2 in adults)
Cellularity
Requires counting 500-1000 cells! → Results highly variable
Differential cell count (cellular distribution)
Estimation of storage Fe (essential in severe anemia diagnosis)
Type and concentration of abnormal aggregates
Most abundant in adult marrow
Neutrophils (various stages)
Which single cell line is the 2nd most abundant in adult bone marrow
RBCs and their precursors
