Hematopoiesis

Question 1

what is hematopoiesis

Answer 1

the formation of blood cells, division and differentiation of blood cells

Question 2

what are the “musts” for hematopoiesis

Answer 2

1. generate a sufficient cell numbers
2. replace cells at differentt rates
3. be able to respond to the environment and body’s needs
4. promote survival of progenitor cells

Question 3

what is the surface phenotype of a pluripotent stem cell

Answer 3

CD34+ and Lin-

Question 4

how abundant are pluripotent stem cells in Bone Marrow

Answer 4

1/1000

Question 5

Summarize Neutrophils

Answer 5

50-75% of WBC
hallmark of inflammation
major line of defense against bacteria

Question 6

summarize basophils

Answer 6

• bi-nuclear

- have granules with amines that cause allergies

Question 7

summarize eosinophils

Answer 7

• have many granules, 1-3% of WBC

- contains major basic protein the kills parasitic worms

Question 8

summarize a monocyte

Answer 8

• irregularly shaped nucleus,
• important in defence
• eventually become macrophages

Question 9

what are the functions of WBCs

Answer 9

• target and eat bacteria
• go through endothelial cell layer
• part of the Innate immune response
  
  • have generic receptors and always ready to go

Question 10

what happens in the mesoblastic phase

Answer 10

• 2 weeks - 2 months
• hematopoeisis occurs in the yolk sac of the embryo
• “blood nests” form

Question 11

what is the hepatic phase of hematopoiesis

Answer 11

-6 weeks - birth
primary site of hematopoiesis occurs in the liver
-lesser extent in the spleen

Question 12

what its he myeloid phase of hematopoiesis

Answer 12

2. 5 months - birth
   - hematopoiesis occurs in the bone marrow beginning in the clavicle
   - continues until hematopoiesis is centered in long bone for the rest of your life

Question 13

describe platelet development

Answer 13

megakaryocyte process budds off platelets

Question 14

if a hematopoietic cell is deprived of colony-stimulating factor such as SCF, it typically ____

Answer 14

dies by apoptosis

Question 15

what is the importance of bone marrow strome

Answer 15

provides nurturing environment for stem cells and developing progenitor cells

• consists of a complex array of cell types
• impacts hematopoietic cells development through
  
  • cell-cell contact
  • cell-bound cytokines/horomone factors
  • diffusible factors

Question 16

what are colony stimulating factors

Answer 16

regulate the self-renewal, maturation/differentiation of early and committed progenitors

Question 17

where do HCGFs come from

Answer 17

secreted by bone marrow stroll cells, macrophage, T-lymphocytes, and many other cell types

Question 18

what are the three groups of HCGFs

Answer 18

1. early
2. intermediate
3. late

Question 19

describe early HCGFs

Answer 19

proliferation/differentiation depends on cytokines most notably SCF, kit ligand and IL-3

Question 20

describe intermediate HCGFs

Answer 20

cytokine receptors change but unregulated later receptors
ex: GM-CSF –> myelocytes
IL-7 -> lymphocytes

Question 21

describe late HCGFs

Answer 21

cytokines that act on committed cell and exclusively induce a single lineage

• G-CSF –> neutrophils
• IL-5 –> eosinophils
• M-CSF –> monocytes/macrophage
• IL-4 –> mast cells
• erythropoietin –> erythrocytes

Question 22

what is the function of LCs

Answer 22

• adaptive immune system

- colonial expansion leading to cell division