Erythropoiesis and Anaemia Flashcards
What are the 3 main components of blood and what are their constituents?
1) Plasma (~55%)
- Abs
- Clotting factors
- Nutrients, electrolytes, hormones
2) Buffy Coat (<1%)
- Platelets
- Leukocytes
3) Haematocrit (~45%for M/42% for F)
- Erythrocytes
What are 3 components of blood plasma?
1) Abs
2) Clotting Factors
3) Nutrients
4) Electrolytes
5) Hormones
What are the components of the buffy coat?
1) Leukocytes
2) Platelets
What are the components of the haematocrit?
Erythrocytes
Rank the components of blood in order of their relative % composition?
1) Buffy coat (<1%)
2) Haematocrit (~42-45%)
3) Plasma (~55%)
Where does haematopoiesis primarily occur in an embryo?
Liver and Spleen
Where does haematopoiesis primarily occur in a neonate/child?
Bone marrow in large bones (eg. tibias, femurs)
Where does haematopoiesis primarily occur in a healthy adult?
Bone marrow in core and trunk (eg. ribs, sternum, vertebrae)
What are the organs involved in medullary haematopoiesis?
Bones with bone marrow
What are the organs involved in extra-medullary haematopoeisis?
Spleen and Liver
When would an adult have a significant extra-medullary haematopoeiesis?
Bone marrow dysfunction
Chronic/excessive bleeding
Chronic/excessive haemolysis
What is the common progenitor cell of platelets and erythrocytes?
Megakaryocyte-Erythroid Progenitor Cell
(From Myeloid Progenitor Cell)
A decrease in RBC would lead to an ___ in platelets.
Increase
(provided the issue isn’t above the lineage of Megakaryocyte-Erythroid Progenitor Cell)
What would be the gross anatomical presentation of extra-medullary haematopoeisis?
Hepatosplenomegaly
Where are mature RBCs physiologically destroyed?
Spleen
How long does an average RBC spend in circulation?
120 days
What is the order of cells in medullary haematopoiesis?
1) Myeloid Stem Cell
2) Proerythroblast
3) Erythroblast
4) Reticulocyte
5) Mature RBC
Myeloid Stem Cells ____ & _____ into Proerythroblasts via stimulation from _______.
Proliferate & Differentiate
via stimulation from erythropoietin
What stimulates the production of proerythroblasts?
Erythropoietin from the Kidney
What essential materials required for the formation of Erythroblasts from Proerythroblasts?
Folate and Vitamin B12
Why does Folate or Vitamin B12 deficiency lead to Megaloblastic anaemia?
The production of Erythroblasts from Proerythroblasts involves further division of cells. Without folate or vitamin B12, cellular contents would increase/replicate but DNA would not, leading to abnormally large cells unable to undergo cell division.
What the most essential component of reticulocyte formation from erythroblasts?
Fe
What are 3 major processes that occur during reticulocyte formation?
1) Filled with Haemoglobin
2) Nucleus reabsorbed/extruded
3) Organelles are broken down into remnants (eg. ER remnants)
What is process of reticulocytes in the bone marrow entering circulation?
Diapedesis
- Flexible membrane of reticulocytes allow squeezing through capillaries to enter blood vessels
