Hematopoiesis

Question 1

Define hematopoiesis

Answer 1

formation of blood

Question 2

Components of Bone Marrow

Answer 2

Red marrow - hematopoietic progenitors and developing cells. decreases with age
Yellow marrow - inactive, fat cells, macrophages, mesenchymal cells. can convert to red marrow in times of need.

Question 3

Mesoblastic stage

Answer 3

Age - embryo
Organs - yolk sac
Cells - nRBC

Question 4

Hepatic stage

Answer 4

Age - embryotic-fetal (6 weeks - 3 months)
Organs - liver
Cells - RBC

Question 5

Medullary (Myeloid stage)

Answer 5

Age - fetal (5+ months)
Organs - Bone marrow, Spleen, Lymphnodes
Cells - All cells

Question 6

Stromal (support cells)

Answer 6

Endothelial - secrete cytokines
Adipocytes - secrete cytokines, growth factors
Macrophages - phagocytosis, secrete cytokines, regulate hematopoeisis
Lymphocytes - secrete cytokines
Osteoblasts - bone forming cells
Osteoclasts - bone resorbing cells

Question 7

What secretes extracellular matrix

Answer 7

fibroblasts and stromal cells
Supports tussue for HSC and developing cells

Question 8

Bone Marrow growth factors

Answer 8

EPO - erythropoietin - promotes RBC production in BM during hypoxia
Thrombopoietin - liver and kidney - develop megakaryocytes into PLT
Cytokines
Estrogen - erythropoiesis
Androgen - erythropoiesis via EPO production
Thyroid hormones - erythropoiesis via Hgb production

Question 9

Cytokines

Answer 9

CSF - colony stimulating factor - myeloblasts into granulocytes
Interleukins - differntiation/maturation/immunological factors
Interferons - differntiation/maturation

Question 10

HSC

Answer 10

Hematopoietic Stem Cells
self-renew
WBC, RBC, PLT or apoptosis

requires extrinsic and intrinsic factors for differntiation

Question 11

Intrinsic factors

Answer 11

genetic composition of cell (genes)

Question 12

Extrinsic factors

Answer 12

cytokines, growth hormones, hormones

Can be used as treatments for clinical application (anemia, immune)

Question 13

Leukopoiesis

Answer 13

WBC production
myelopoiesis (granulopoiesis)
lymphopoiesis

Question 14

Three pools in Bone marrow

Answer 14

Stem cell pool
Proliferation pool (mitotic)
Maturation pool (storage)

Question 15

Stem cell pool

Answer 15

HSC

Question 16

Proliferation pool

Mitotic

Answer 16

Dividing cells
CMP - common myeloid progenitor
CFU GMP - genulocyte macrophage proginetor cells
CMP/CFU - myeloid (4-6 days to mature)

Question 17

Maturation pool

storage

Answer 17

nuclear maturation
cells ready to release into peripheral blood
metamyelocyte - segmented cell (4-6 days to mature)

Question 18

Marginating pool

Answer 18

loosely localized to walls of capillaries
liver, spleen, lung

Question 19

Circulating pool

Answer 19

circulating in blood vessels

Question 20

How do WBC cells enter cirulation

Answer 20

endothelial cells lining vessels
short life span in tissues
replaced by cells in storage pool
Unused cells - apoptosis

Question 21

Physiological cause of leukocytosis

Answer 21

non-pathological
Strenuous exercise
Emotional stress
Labour
Increased epinephrine

Question 22

Pathological cause of leukocytosis

Answer 22

Disease process
Bacterial infection
Neoplasms (leukemia)
Acute hemorrhage
Tissue damage
Drugs/toxins
Inflammatory disorder

Question 23

Granulopoiesis

Answer 23

Myeloblast - Promyelocyte - Myelocyte - Metamyelocyte - Band - Polymorphonuclear

Question 24

granule containing WBC

Answer 24

innate immune system
Neutophils, eospinophils, basophils