Haematopoiesis Flashcards
What are the three phases of the developmental pathway of erythropoiesis?
Phase 1 = ribosome synthesis
Phase 2 = Hgb accumulation
Phase 3 = ejection of nucleus
Immature form of RBC
Reticulocyte
Where is EPO used in erythropoiesis?
In the erythropoietin dependent path.
Iron dependent for what stage of erythropoiesis?
From erythroblasts to reticulocytes
How long can one RBC cell live?
100 - 120 days
What stage is this?
“synthesis of hemoglobin “
Proerythroblast
What stage is this?
“Nucleoli disappear”
Early normoblast
What stage is this?
“Hemoglobin starts appearing”
Intermediate normoblast
In the late normoblast, what happens?
The nucleus starts to disappear
What happens to the reticulum in reticulocyte and matured RBC?
Reticulum is formed in reticulocyte but it disappears when matured.
Role of vitamin C in erythropoiesis
Helps in iron absorption
_________ is needed for absorption of vitamin B12
Intrinsic factor
Androgen,_____, ______ and ACTH are hormones needed in erythropoiesis
Growth Hormone , Thyroxine
**RBC is slightly higher in male because androgen is for male sexual reproduction.
Three types of vitamin B that is needed in erythropoiesis
Vitamin B6, B12 and B9 (folic acid)
What is another name for erythropoetin?
Haemopoetin
Erythropoietin (EPO) is a glycoprotein cytokine produced in the _________
Kidney
Synthetic EPO is used clinically to treat ________
Anaemia
_______ stimulates EPO production, which then stimulates erythrocyte production in bone marrow
A state of reduced oxygen carrying capacity (hypoxia)
_______ are also used as illegal sports enhancing drugs
Synthetic EPO , so the athletes can increase number of RBC, which in turn increases aerobic capacity
How EPO increases production of RBC?
Hint: Three ways it affects
- promotes pronormoblast production
- Shorten transition time in normoblast stage
- promote early release of reticulocytes
Name the six other sites where EPO has an effect on:
- Brain (protection form ischemia)
- endothelium (vascular tone)
- heart (protection form ischemia)
- myoblast (wound healing)
- white fat
- bone (remodeling)
There is a decrease in cell size as RBC matures. True or False
True
Two changes in intermediate normoblast
Loss of mitotic activity and hemoglobinization
Change of RBC shape from _______ to _____ as it matures.
Globular , biconcave
______ , _______ and ________ disappears as RBC matures.
Nucleus, mitochondria and RNA
The staining of RBC will change as it matures. What changes?
From basophilic to eosinophilic
Granulopoesis is the formation of _______ which are ____, ____ and _____.
granulated WBC, eosinophils, neutrophils and basophils.
______ lymphocyte mature in bone marrow, _____ lymphocyte mature in thymus.
B lymphocyte in bone marrow, T lymphocyte in thymus
Triggered monocytes turn into ______ in the tissues
Macrophage
What is thrombopoeisis?
Formation of platelets
Precursors of platelets are ________, _____ and ________.
Megakaryoblast, promegakaryocyte and megakaryocyte (in this order).
Then fragmentation of megakaryocyte turns into platelets
Megakaryocytes will form pseudopodia which then becomes ______ and are released are fragmented into platelets.
Proplatelets
Action of thrombopoietin (TPO) decreases slowly as we approach the end of thrombopoesis. True or False?
FALSE. In fact it becomes more dominant as we approach the end.
Hematopoiesis outside of the bone marrow is called___________
Extramedullary hematopoiesis (EMH)
In fetal development, extramedullary hematopoiesis (EMH) happens at the ______and ____.
Liver and spleen
** after this, progenitor cells would migrate to bone marrow
In ______, hematopoietic factors (e.g_______) promotes EMH in the liver and spleen.
infection, Toll like receptor (TLR) ligands
** other than infection, marrow failure and increase demand of RBC also promotes EMH
EMH can also occur in:
skin, lungs, lymph nodes, urogenital system, paraspinal spaces, retroperitoneal
Give an example of active EMH and passive EMH each.
Active EMH = fetal development or infection (immune response)
Passive EMH = failed marrow
Insufficient production or maturation of blood cells due to ______
Inadequate EMH
Excessive EMH occurs in___
- autoimmune diseases
- chronic infection
Jojo has an overly activated EMH, what are the possible presentations?
Jojo would have an enlarged organ depending on the site of EMH. Most likely hepatomegaly or splenomegaly or even hepatosplenomegaly.
Another presentation is the formation of calcified spicules at the skull under X-ray. Known as “Hair-on-end” appearance.
