blood

• blood function

  • distribution
  • regulation
  • protection
• blood distributes 


  oxygens, nutrients, carbon dioxide and waste products
• blood regulates 


  body temperature, pH and fluid volume
• blood protects 


  against haemorrhage (fibrinogen), against infection (leukocytes)
• about 5 L of blood in the body
• blood accounts for about 8% of body mass
• anticoagulant prevents 


  blood clotting
• RBCs AKA


  erythrocytes
• WBCs AKA


  leukocytes
• platelets AKA 


  thrombocytes
• when anticoagulant is used when separating blood 3 layers form

  1. plasma (55%)
  2. buffy coat containing WBCs and platelets
  3. red blood cells (45%)
• without anticoagulant when separating blood 3 layers form

  1. serum (fibrinogen depletion, as converted to fibrin)
  2. buffy coat (WBCs and platelets)
  3. clot (containing RBCs and fibrin)
• antibodies AKA


  immunoglobulins
• blood plasma contains

  • important proteins such as albumins, globulins, fibrinogen
  • water
  • electrolytes
  • nutrients
  • gases
  • regulatory substances (hormones)
• formed elements in the blood (3 groups)

  1. red blood cells
  2. white blood cells
  3. platelets
• subtypes of WBCs

  • neutrophils (60-70%)
  • lymphocytes (20-25%)
  • monocytes (3-8%)
  • eosinophils (2-4%)
  • basophils (0.5-1%)
• haemopoiesis is 


  production of blood cells
• all blood cells develop from pluripotent stem cells form the red bone marrow of long bones
• eosin stain will stain

  basic/alkali components red
• methylene blue stains 


  acidic components blue
• wright's stain is 


  eosin and methylene blue
• acidic components of the blood

  DNA in the nucleus
• basic components of the blood

  eosinophil basic proteins
• basophils characteristics 


  bilobed nucleus, blue granules (histamine)
• eosinophils characteristics 


  bilobed nucleus, red granules (basic protein)
• neutrophils characteristics 


  multi-lobed nucleus, few granules
• monocyte characteristics 


  horse-shoe shaped nucleus, large cells
• platelets are not cells so have

  no nucleus and are small
• monocytes exist for a short time before differentiating into 


  macrophages
• macrophage role 


  phagocytic immune cell engulfs bacteria
• B cells turn into plasma cells and secrete 


  antibodies
• red blood cells evolve through myeloid lineage, originally having nucleus to make haemoglobin before ejecting the 


  nucleus
• erythropoiesis is 


  formation of RBCs in the red bone marrow
• erythropoietin stimulates 


  erythrocyte formation (in the kidney)
• erythrocyte structure

  • anuclear
  • biconcave shape
  • haemoglobin (33% of weight)
• erythrocytes function

  • oxygen transport
  • CO2 removal
• 2 million erythrocytes are made per 


  second
• erythrocytes last approximately 120 days
• 2 categories of leukocytes

  • granulocytes
  • agranulocytes
• leukocytes function 


  protection