Erythropoiesis

Question 1

Where does erythropoiesis usually take place in adults?

Answer 1

• red bone marrow
  => flat bones - vertebrae, ribs, and sternum
  => proximal ends of long bones

Question 2

Where does erythropoiesis take place in the foetus?

Answer 2

LIVER

Question 3

Erythrocytes originate from what type of precursor?

Answer 3

Myeloid precursor

Question 4

Describe the stages of differentiation during erythropoiesis

Answer 4

Haematocytoblast - Multipotent stem cell
Proerythroblast - Cell committed to its developmental pathway
Basophilic erythroblast - Ribosomes accumulate, nucleus shrinks
Polychromatophilic erythroblast - Nucleus + total cell volume shrinks
Normoblast Nucleus is ejected
Reticulocyte Cells enter the circulation
Erythrocyte Fully matured cell

Question 5

What regulates erythropoiesis?

Answer 5

erythropoietin (EPO)

Question 6

Where is EPO produced and what is it produced in response to?

Answer 6

produced in the kidneys on detection of decreased oxygen levels in the circulation.

Question 7

What does EPO do to aid erythropoiesis?

Answer 7

increases uptake of iron, heme biosynthesis, and globin gene transcription

Question 8

How long does it take our body to make new RBCs? How long is their lifespan

Answer 8

Production of new erythrocytes ~1 week
lifespan ~ 120 days.