Week 3

Question 1

Hematopoesis

Answer 1

• creation of RBC

- Start in yolk sac; occurs in liver, and spleen for first couple of week of life; bone marrow produces for rest of life

Question 2

extramedullary hematopoesis

Answer 2

Periods of extreme stress can cause blood cells being made in liver and spleen again

Question 3

Hemaopoesis steps

Answer 3

hematopoetic stem cell–myeloid line–myeloid stem cell (EPO)–progenitor cell–proerythroblast–basophilic erythroblast–polychromatophilic erythroblast–orthochromatophilic erythroblast (nuceleus ejected)–reticulocyte – erythrocyte

Question 4

Which cell can self-renew in hematopoesis?

Answer 4

-only hematopoetic stem cells

Question 5

Look of cells with maturation

Answer 5

As cells mature they get smaller, nucelus gets darker, and cytoplasm goes from purple to pink (due to creating hemoglobin)

Question 6

How to differentiate reticulocyte

Answer 6

Need supravital stain to stain RNA in reticulocyte

Question 7

What controls hematopoesis?

Answer 7

EPO

- binds to erythropoietic progenitor cell

Question 8

What causes stem cells to replicate?

Answer 8

-times of stress

Question 9

What is released due to anemia?

why?

Answer 9

• Kidney will make because it senses hypoxia with hypoxia inducible factor
• EPO will go to bone marrow and bind to EPO receptor on progenitor cell

Question 10

What happens with binding of EPO to progenitor cell?

Answer 10

-Binding of EPO to EPOR will bring ends of EPOR together (tyrosine kinase), and Jak2 autophosphorylates, increases transcription and cell differentiation

Question 11

What happens to EPO with CKD?

Answer 11

• will have low erythropoietin because kidneys under stress

- so unable to replace RBC, leading to anemia

Question 12

Erythrocytosis/ polycythemia

Answer 12

elevated hemoglobin and hematocrit

Question 13

Primary erythrocytosis

Answer 13

-low EPO

Question 14

Secondary erythrocytosis

Answer 14

-high EPO

Question 15

High hemoglobin and hematocrit; low erythropoietin

Answer 15

RBC’s differentiating without EPO

Question 16

V617F Jak2-mutation

Answer 16

• Gain of function mutation: constituively activates Jak 2– does not need binding of EPO for Jak2 to be activated and create RBC
• Polcythemia vera

Question 17

Eero Mantyranta

Answer 17

• olympic gold medal winner
• Contained familial form of erythropoietin receptor mutation that allowed for increase in RBC; Had high hemoglobin and hematocrit; increase in oxygen carrying capacity

Question 18

Polycthemia vera complications

Answer 18

When you have increased RBC, blood becomes thicker, clogs vessels and can cause low oxygen to tissue

Question 19

Treatment for polcythemia vera

Answer 19

• will go through therapeutic phlebotomy (periodic blood donation)
• Could also use JAK2 inhibitor

Question 20

High Hemoglobin, hematocrit, and EPO

Answer 20

• caused by tumor ( Glio-blastoma: brain tumor; most common type of tumor to secrete EPO, because very angiogenic)
• Similar symptoms as with low EPO, except for speech disturbances
• Will also treat with therapeutic phlebotomy, low dose aspirin, hydroxyurea, Jak 2 inhibitors

Question 21

High hemoglobin and hematocrit, EPO normal

Answer 21

• caused by dehydration
• Pseudo polycythemia: Hemoglobin is a concentration, so if blood volume is low will look like concentration of hemoglobin is elevated