Genesis of the blood cells. Erythropoietin. Thrombopoetin Flashcards
genesis of blood cells - intro
genesis of blood cells = hematopoesis
takes place in adults = bone marrow, foetus = yolk sac
conversion of pluriopotent self renewing hematopoietic cells differentiation/ maturation into specific blood cell
genesis of blood cells - 1
Hematopoietic Stem Cells
- undifferentiated stem cells differentiate into multipotent progenitors
- these have less potential but can turn into limited blood cells
genesis of blood cells - 2
multipotent progenitor cells -> comitted progenitor cells
- specific to a lineage which matures into specific blood cell
genesis of blood cells - 3
commited progenitor cells -> differentiate into desired blood cell
genesis of blood cells - types
B
E
N
M
L
EPO list
structure
location
function
regulation
clinicals
EPO - structure
EPO = glycoprotein hormone
EPO - locations
liver = foetus
kidney = adults
EPO - FUNCTION
1 - the specialised cells in kidneys detect low levels of o2 (hypoxia)
2 - in response to this, kidney cells secrete EPO into bloodstream
3 - EPO travels to bone marrow erythyroid progenitor cells
3 - these cells differentiate + mature into RBCS
EPO - REGULATION
hypoxia inducible factors HIFs
- transcription factors
- activate during hypoxia
negative feedback mechanisms
- normal O2 levels = less EPO activity
EPO - clinicals
anaemia = insufficient EPO production
TPO list
structure
location
function
regulation
TPO - structure
= glycoprotein hormone
- 353 amino acids
TPO - location
liver = primary
kidney = secondary
TPO - FUNCTION
1 - blood detects low levels of platelets
2 - TPO released by liver
3 - TPO binds to c-Mpi receptors on bone marrow megakaryotic progenitor cells
= activation of Jak-stat pathway
4 - megakaryocytes -> platelets
