BLOOD CELLS

• Erythrocytes - contain the protein hemoglobin to transport O2 and CO2; approximately 7.2 nanometers in diameter
• Hemoglobin consists of 2 parts: heme and globin
• The normal life span for an erythrocyte is 120 days
• Leukocytes - provides immunity to certain diseases by producing antibodies and destroying harmful pathogens by phagocytosis
• Normal number of leukocytes for an adult is 4,500 to 11,000 pero nanoliter of blood
• Leukocytes from most to least numerous:

  • Neutrophils (50-70%)
  • Lymphocytes (18-42%)
  • Monocytes (2-11%)
  • Eosinophils (1-3%)
  • Basophils (0-2%)
• Neutrophils - provides protection against infection through phagocytosis; multi-lobed nucleus; increased in patients with bacterial infections
• Lymphocytes - provide the body with immune capability by means of B and T cells; increased in patients with viral infections
• Monocytes - largest circulating leukocytes; act as powerful phagocytes to digest foreign material; increased in patients with intracellular infections
• A tissue monocyte is known as a macrophage.
• Eosinophils - detoxify foreign proteins; increased in patients with allergies, skin infections, and parasitic infections
• Basophils - least common of the leukocytes; releases histamine in the inflammation process and heparin to prevent abnormal blood clotting
• Thrombocytes/Platelets - formed from megakaryocytes; plays a vital role in blood clotting in all stages of the coagulation mechanism
• Platelets have a life span of 9 to 12 days.
• The average number of platelets is 140,000 and 440,000 per nanoliter of blood.