Blood

Plasma

  • mixture of water, sugar, fat, protein, and salts
  • transport blood cells throughout your body along with nutrients, waste products, antibodies, clotting proteins, chemical messengers such as hormones.

Red Blood Cells

  • Aka erythrocytes or RBCs
  • 40 to 45 percent of volume.

Structure

  • biconcave disk with a flattened center. like a donut
  • no nucleus and so can easily change shape, helping them fit through the various blood vessels in your body.
  • contain hemoglobin - carry O₂ and CO₂.

Production

  • Production controlled by erythropoietin, a kidney hormone
  • start as immature cells in the bone marrow and after approximately seven days of maturation are released into the bloodstream
  • Lack of nucleus limits the life of the cell as it travels through the smallest blood vessels, damaging the cell’s membranes and depleting its energy supplies. The red blood cell survives on average only 120 days.