Red blood cells

shape and gross structure

  • biconcave
  • 7.8 micrometers
  • pretty dang flexible
  • produce ATP via anaerobic respiration
  • no ribosomes or mitochondria

erythropoietin (EPO)

  • produced in the kidneys
  • stimulus: hypoxia

reticulocytes

  • earliest immature RBCs
  • 0.5-2% of circulating RBCs
  • circulate 1-2 days
  • contain reticulum = reticular mesh network of ribosomal DNA
  • cresyl blue staining (for RNA)

mature erythrocytes

  • no mitochondria

what's all this about buffers then?

  • they can transport large amounts of CO2 as bicarb! thanks to carbonic anhydrase
  • transported to lung and excreted
  • bicarbonate-chloride carrier protein means HCO3 diffuses out from red cells to plasma, and Cl diffuses in instead = chloride shift
    • Intracellular Cl concentration higher in venous RBCs
  • see Carbon dioxide transport