IMIN Topic Three

• all mature blood cells including WBC and RBC arise from hematopoietic stem cells
• hematopoiesis is the process of formation and differentiation of blood cells and occurs in bone marrow
• hematopoietic cells are almost immortal as they are self renewing
• myeloid and lumphoid progenitors can both make dendtritic cells
• t cells are the only cells that can leave the bone marrow before mature without causing adverse effects
• TH cells produce cytokines and are major regulators in fighting infections
• TC cells are programmed killers
• RBC have the highest concentration in body with a lifespan of about 120 days
• Platelets live for anywhere from 5-10 days
• neutrophils are the most abundant leukocytes and acount for 50-70% of all WBC
• lymphocytes have a longer lifespan as they are the memory cells for disease, they can live anywhere from days to many years
• lymphocytes account for 20-40% of WBC
• Hematoxylin binds basophilic cells (-) — typically nucleic acids
• Eosin binds easinophilic protiens (+) in the granules and cytoplasm
• Myleoid lineage cells include;

  • RBC
  • granulocytes
  • monocytes
  • macrophages
• granules 


  membrane-bound internal vesicles that release their contents in repsonse to infection
• Nuetrophil;

  1. most abundant class of WBC
  2. numbers increase during an infection
  3. recrutied to sites of infection in repsonse to chemoattractnant molecules
  4. can directly destroy pathogens using various mechanisms

  • dominant forst repsonder to infections