ToB - blood (session 10) Flashcards
where are blood cells created
bone marrow
haemopoietic progenitor - stem cells
where are blood cells derived from? name each subtype
myeloid blasts (platelets (megakaryocytes), monocytes (macrophage), erthrocytes (RBC), granulocytes (WBC))
OR
lymphocytes (B & T cells)
what is development of blood cells driven by?
cytokines
what causes blood cells to remain in the bone marrow?
adhesion molecules (e.g. collagen) up-regulated down-regulated to release blood cells into circulation
how is erythrocytes production regulated? what is the 1/2 life of erythrocytes?
negative feedback
production of erythropoietin at the kidneys in response to hypoxia (lack of O2, decrease pO2)
stimulates erythrocyte production
1/2 life of 120 days
How is damaged or dying RBC broken down and removed?
spleen breaks down damaged or dying RBC and liver (urea) removes products from the body
what is the function of RBC? and structure
deliver O2 to tissues
carry haemoglobin
maintain haemoglobin in its reduced (ferrous) state - Fe2+
maintain osmotic equilibrium
generate ATP
biconcave flexible disc
faulty RBC removed by spleen & broken down
where are platelets produced? how?
produced by megakaryocytes
increase in size and replicate DNA
platelets bud from cytoplasm
controlled by thrombopoietin (TPO)
what is the structure of platelets and where are they stored?
no nucleus
stored in spleen
what is the function of platelets?
adhesion to CT & aggregation with other platelets to form a platelet plug
involved in activation of the clotting cascade
fibrin mesh traps platelets and RBC
what is the structure of neutrophils (nucleus) and function?
contain multi-lobed nucleus
enhance chemotaxis - movement changed by chemicals (go to where is needed)
enhance phagocytosis and killing of pathogens
migrates out of circulation to site of infection
kills pathogen by release of cell contents, once all released, neutrophils die
the 1st cell that triggers the rest into action
what do monocytes look like and function?
largest cell in the body and will move to certain tissue types and differentiate
large nucleus kidney shaped
lots of phagocytic potential as they turn into macrophages & interact with T cells
what do eosinophils look like and function?
Bi-lobed nucleus fight parasites e.g. worms contain many granules in ALLERGIC reactions can phagocytose, cause damage by releasing cytotoxic particles
what are basophils structure & function? where is it found?
found in the blood (unlike mast cells)
rare
hard to see nucleus
allergic reactions - mediate acute inflammatory by histamine & heparin
what are mast cells structure and function? where is it found?
v similar to basophil
found in tissues NOT blood
different progenitor (originate)
