Hematopoiesis Flashcards
Process of blood cell formation
Hematopoiesis / Hemopoiesis
Classical marker of hematopoietic stem cells
CD 34
When does Hematopoiesis start ?
19th Day of embryonic development following fertilization
1st blood cell formed during the first 2-8 weeks of life
Primitive erythroblasts
Hemoglobin in primitive erythroblasts
Gower 1, Gower 2, Portland
First fully developed organ in the fetus
Thymus
Predominant Hemoglobin in Hepatic phase of Hematopoiesis
Hb F
What are the three phases of hematopoiesis
- Megaloblastic / Mesoblastic
- Hepatic
- Myeloid / Intermedullary / Medullary
Process of replacing red marrow by yellow marrow during development (between 5-7 years of age)
Retrogression
Situations wherein yellow marrow can revert back to its active state
Hemolysis and excessive blood loss
Site wherein Red marrow and Yellow marrow can be seen
RSVP Ribs Sternum Vertebrae Pelvis and Proximal ends of the long bones
In adults there is approximately _ % of yellow marrow and _ % of red marrow
50: 50
Hematopoietically active marrow
Red marrow
Prevalent cells in the yellow marrow
Adipocytes
Primary lymphoid organs
Bone marrow and thymus
Major secondary lymphoid organs
Spleen and Lymph nodes
Largest secondary lymphoid organ
Spleen
Increased hemolytic activity of the spleen caused by splenomegaly
Hypersplenism
Responsible for extramedullary Hematopoiesis as response to infectious agents or in pathologic myelofibrosis
Liver and Spleen
Preferred site for BM aspiration in adults
Posterior / Anterior superior iliac crest
Preferred site for BM aspiration in children less than 2 years of age
Tibia
Normal M:E ratio in adults
myeloid: erythroid
2:1 to 4:1
M:E ratio of patients with leukemia
10:1
Recommended cells to be counted in the marrow differential
At least 500 cells * preferably 1,000 cells
Bone marrow removed intact without disturbing the bone architecture
Bone marrow biopsy
* BM aspirate - disturbs bone marrow architecture
BM smears should be kept for how long ?
10 years
Specimen used for cell morphology from the bone marrow
Bone marrow aspirate
Blood cell production outside the bone marrow
Extramedullary Hematopoiesis
Blood cell production inside the bone marrow
Medullary Hematopoiesis
Characteristic of extramedullary Hematopoiesis
Hepatomegaly and/or Splenomegaly
Process of RBC formation
erythropoiesis
Site of erythropoiesis
Bone marrow
What is the phase name of aorta-gonad mesonephros region?
Mesoblastic Phase
What is the major site of adult blood formation in the embryo?
Yolk sac
Suckling pig phenomenon
RBCs ingest iron from macrophage
What are the 2 uses of macrophages?
- Adhesion (para ‘di maagang lumabas si RBC nang maaga)
2. Cytokines (RBC communicate through cytokines)
_ mL of blood per minute passes through the spleen
350 mL
Difference of culling and pitting
Culling - killing
Pitting - only remove certain defective parts
Physiologic cell destruction occurs in:
- Liver - Kupffer cells
2. Spleen - Culling & pitting
Fraction of platelets stored in the spleen
1/3
Fraction of WBCs stored in the spleen
1/4
Removal of the spleen
Splenectomy
Spleen killed itself
Autosplenectomy
The condition that causes autosplenectomy
SICKLE CELL ANEMIA
Origin of hematopoietic progenitor cells that is believed now
Monophyletic theory
Precursor vs Progenitor
Precursor: Dedicated to a certain cell (Distinguished)
Progenitor: General (Not distinguished)
