Flashcards in Hematopoiesis Deck (24):
In what week of gestation does fetal hematopoiesis begin?
What is the sequence of embryonic organs that take over hematopoiesis?
Young (1) Liver (2) Synthesizes (3) The (4) Blood
(4) Bone marrow
What are the five white blood cell types, in order of prevalence?
Never Let Monkeys Eat Bananas
When does medullary hematopoiesis (in bone marrow) begin in the fetus?
5 months of gestation
What is a characteristic feature of stem cell division in hematopoiesis?
Asymmetry - one cell retains properties of the stem cell
What are two causes of induced hematopoiesis?
(1) Infection leads to increased production of neutrophils
(2) Anemia leads to increased production of RBCs
What do stromal cells in bone marrow do?
(1) Nurture and protect stem cells, (2) secrete factors that are chemotactic for hematopoietic cells
Where are bone marrow aspirations drawn from in children?
What is the term for replacement of cellular bone marrow with fat? At what age does this occur?
Involution at 5-7 years
After ~20 years, where is cellular marrow found?
(7) Proximal ends of long bones
How long does it take reticulocytes to mature to RBCs?
About 3 days (2 in bone marrow + 1 in peripheral blood)
What is a marker for hematopoietic stem cells?
Where are neutrophils found?
(1) 50% in marginal neutrophil pool and (2) 50% in circulating neutrophil pool
What do steroids do to neutrophil populations?
Movement from marginal neutrophil pool to the circulating neutrophil pool
How long do neutrophils circulate?
What is the life span of RBCs and platelets?
RBCs: 120 days
Platelets: 7-10 days
When are hypersegmented neutrophils found?
Folate and vitamin B12 deficiency
What are G-CSF and GM-CSF and what do they do?
Granulocyte colony stimulating factor and granulocyte-macrophage colony stimulating factor - stimulate differentiation and mobilization of stem cells into peripheral blood
What stimulates the differentiation and maturation of megakaryoblasts and megakaryocytes?
Where are bone marrow aspirations drawn from in adults?
Posterior superior iliac crest
What is the term for variation in RBC diameter on blood film?
What are the staining characteristics in Wright stain?
(1) Methylene blue stains acidic structures blue (basophils)
(2) Eosin stains basic structures pink (eosinophils)
(3) Neutrophils are purple from being stained by both methylene blue and eosin
What is a band shift or left shift?
(1) Increase in bands and immature neutrophils in peripheral blood (2) due to proliferation of myeloid cells