Haemopoiesis, Spleen and Bone Marrow Flashcards
What is haemopoiesis?
production of blood cells
where does haemopoiesis occur?
bone marrow
bone marrow in infants
extensive throughout skeleton
where is bone marrow in adults found?
pelvis
sternum
skull
ribs
vertebrae
Trephine biopsy
used to take sample of bone tissue
Haemopoietic stem cells
unique ability to give rise to all of the different mature blood cell types
given appropriate stimuli can differentiate into variety of specialised cells
what is the differentiation of Haemopoietic stem cells determined?
-hormones
-transcription factors
-interactions with non-haemopioetic cell types
what cells can Haemopoietic stem cells form?
platelets
basophil
neutrophil
eosinophil
monocyte
t lymphocyte
erythrocyte
Thrombopoiesis
production of platelets
Platelets have no nuclei and are essentially membrane bound fragments of cytoplasm that bud off from megakaryocytes
Erythropoiesis
production of red blood cells
Granulopoiesis
production of neutrophils, eosinophils, and basophils
Monocytopoiesis
production of monocytes
What do granulocytes arise from?
myeloblast cells which in turn arise from common myeloid progenitor cells
what do monocytes do?
Monocytes circulate in the blood for ~1-3 days before moving into tissues where they differentiate into macrophages or dendritic cells
can also perform phagocytosis after recognising antibodies or complements that coat pathogen or by binding directly via pattern-recognition receptors that recognize pathogens.
lymphopoiesis
production of lymphocytes
erthropoietin
Secreted by the kidney and stimulates RBC development
thrombopoietin
produced by liver and kidney regulates production of platelets
sources of HPSC
bone marrow aspiration
GCSF mobilised peripheral blood stem cells
umbilical cord stem cells Leicester has cord bank
haematological procedure
HPSC transplantation
extra medullary hematopoiesis
production outside of the bone marrow -liver, spleen, or other tissues happens in pathological conditions
myelofibrosis or thalassaemia can mobilise into circulating blood to colonise other tissues
what are haemopoietic cells capable of?
self renewal
what is the reticuloendothelial system?
is a network of cells located throughout the body and is part of the larger immune system. The role of this system is to remove dead or damaged cells and to identify and destroy foreign antigens in blood and tissues
what is the reticuloendothelial system made up of?
monocytes
main organs in reticuloendothelial system
spleen and liver