Hematopoiesis III

Question 1

Cytokines criculate in _____ [ ] but can increase up to ______ fold during trauma or infection

Answer 1

very small concentration and can increase up to 1,000x

Question 2

Bone marrow stromal cells control

Answer 2

Hematopoiesis via cytokines

Question 3

Types of cytokine action

Answer 3

Autocrine: cells secretes a cytokine that stimulates itself
Paracrine: cell secretes cytokine that acts on nearby cell
Endocrine: cell secretes cytokine that acts on cell elsewhere in the body

Question 4

How are hormones and cytokines different?

Answer 4

Cytokines are potent activators at low [ ] in the body.

Made by many cells throughout the body.

Question 5

Cytokine SCF binds to….

Answer 5

receptor c-Kit on HSC

Question 6

Erythropoietin

EPO

Answer 6

Method that kidney communicates with bone marrow to make more RBCs
Kidney produce HIF translates EPO to make RBCs
EPO stims CFU-EMk to make RBCs
NB: production of RBCs also requires IRON
EPO does not act on erythrocytes
EPO takes several weeks to become effective

Question 7

Thrombopoietin

TPO

Answer 7

Stimulates production of Megakaryocytes and ultimate platelets
TPO made in liver
NB: TPO is absorbed by platelets when there is enough TPO in circulation
normal platelet # 10^11 qd

Question 8

Platelet Regulatory Factors

Answer 8

Early: Stem Cell Factor (SCF), GM-CSF, IL3
Late: TPO

Question 9

Cytokines that stimulate CFU-GM

Answer 9

G-CSF and GM-CSF

Question 10

G-CSF

Answer 10

G-CSF made by fibroblasts, endothelial cells and macrophages of all organs
G-CSF increases neutroophil # and function
NB: ACTS ON CFU-GM

Question 11

GM-CSF

Answer 11

made by stromal cells, endothelial cells and T-cells
Increases neutrophil, monocyte, and eosinophil number and function
NB: GM-CSF acts on GM-CFU

Question 12

SCF

Answer 12

Stem Cell Factor acts on stem cell hematopoeitc stem cell

NB: receptor c-kit