Blood components

• Blood has four main components: red blood cells, white blood cells, plasma, and platelets. 
• Red blood cells:

  • Biconcave- shaped
  • Make up 40-45% of blood by volume
  • Do not contain DNA
  • Life span of 120 days
• White blood cells:

  • Classified as myeloid or lymphoid cells
  • Myeloid cells - neutrophils, monocytes, eosinophils, mast cells and basophils
  • Lymphoid cells - T cells, B cells and natural killer cells
  • Neutrophils are the most numerous - multilobed nucleus
• Plasma:

  • Liquid portion of blood
  • Makes up 55-60% of blood by volume
  • Clear or straw yellow in colour
  • Mostly water but also contains:
  • Amino acids
  • Electrolytes
  • Gases
  • Nitrogenous waste
  • Nutrients: including glucose and fat particles
  • Proteins: including albumin, globulins, enzymes, clotting factors like fibrinogen, and hormones
• Platelets, or thrombocytes, are cell fragments that circulate until removed by the spleen, or are recruited to a site of injury and activated to participate in the clotting process.