Haem Erythropoeisis

Question 1

What are the sites of R.B.C during life stages?

Answer 1

Early Foetal life-yolk sac
Foetus 2nd-7th month- liver, spleen and lymph nodes
Foetus 8-9th month- bone marrow
Childhood-marrow of all bones
Adolescent-marrow of: sternum, ribs, vertebrae, skull, pelvis long bones,
Adult-marrow of bones that are not long bones

Question 2

Why does red blood cell production move from long bones to the axial skeleton?

Answer 2

During growth there is a fatty replacement in long bones, therefore you hematopoietic marrow is confined to the central skeleton.

Question 3

what are the formation stages in erythropoeisis?

Answer 3

HSC
EARLY BFU-E
LATE BFU-E
PRO-E
BASO-E
ORTHO-E
Reticulocyte
R.B.C

Question 4

What are the progenitor, erythroblast precursors and erythrocytes?

Answer 4

Progenitor-HSC, BFU-E
Erythroblast precursors-PRO-E, BASO-E, ORTHO-E
Erythrocyte-reticulocyte, R.B.C

Question 5

What is the first recognizable cell in erythroblast

Answer 5

proerythroblast

Question 6

what cells are made from the myeoloid stem cell?

Answer 6

R.B.C
B.E.N Granulocytes
Monocytes
platelets

Question 7

Characteristics of Proerythroblasts

Answer 7

First recognizable cell
large cell with dark blue cytoplasm
Haemoglobin synthesis begins here under EPO

Question 8

Why is EPO important for Pro-erythroblast?

Answer 8

EPO activates genes to make RNA and this generates the formation of Hb
Dogma: DNA–>RNA–> Protein
Hb is a protein

Question 9

What are the characteristics of Baso-E?

Answer 9

Very blue due to production if RNA
Base-loving
Increased RNA activity

Question 10

What are the characteristics of Poly-E?

Answer 10

Cytoplasm paler blue due to some RNA lost
Chromatins condense
decreased transcription and translation due to decreased RNA
Increased Hb production

Question 11

What are characteristics of Ortho-E?

Answer 11

Nucleus very condensed
increased Hb
Nucleus and mitochondria are extruded from the cells for macrophages

Question 12

Characteristics of the Reticulocyte

Answer 12

contains some RNA
Slightly larger than mature RBC
Circulates in the peripheral blood 1-2 days before maturing

Question 13

Erythrocyte characteristics

Answer 13

RNA completely lost
Pink stains
Mature RBC
Completely enucleated and bi-concave

Question 14

How long does erythropoiesis occur?

Answer 14

It takes 48 days?

Question 15

Requirements of Erythropoiesis

Answer 15

-Hormones-:EPO, Stem cell factors and growth factors
-Metals: cobalt, fe2+,mn2+, Nickel
-Vitamins: B12, Folate, riboflavin, Vitamin C, B6
Amino Acids: essential acids

Question 16

What do the metals and vitamins do?

Answer 16

Cobalt-stimulate production of EPO and stabilized HIF
Fe2+-need for Hb production
Mn2+-maintains homeostasis
Nickel-stimulates EPO

B12- Hb synthesis and B9 synthesis
b9- Hb synthesis
Riboflavin-contains Reduced glutathione that concerts methahaemoglobin to Hb
B6-nutrition factor

Question 17

Characteristics of EPO

Answer 17

90% formed in the peritubular interstitial cells of the kidney
10% in liver and elsewhere
stimulated by oxygen tension in the tissues

Question 18

Formation of EPO

Answer 18

Hypoxia induces production of HIF
HIF creates REPC
REPC creates EPO
EPO makes: epo production, new vessels, transferrin receptors

Question 19

adverse effects of EPO

Answer 19

increased blood viscosity
sudden death

Question 20

what are the growth factors?

Answer 20

IL-3,4,5 Tcells
IL-6 Macrophages
EPO-Kidneys
G,M, GM-CSF- monocytes, fibro etc
SCL-kidney and kupffer cells