Ch8 transport in humans

• Plasma

  • mostly water
  • the medium for transporting substances throughout body
  • Helps distribute heat throughout body to maintain temperature
• substances that plasma transport

  • water
  • carbon dioxide ( as gas or hydrogencarbonate ions)
  • nutrients eg glucose
  • urea
  • hormones
  • antibodies
  • fibrinogens ( turned into fibrins to trap blood platelets for blood clotting)
• rbc

  • biconcave disc (unobservable in 2d micrograph, can only say centre is lighter and peripheral is dimmer)
  • small
  • red due to haemoglobin
  • no nucleus when mature
  • produced in bone marrow
  • broken in liver and spleen (haemoglobin is broken into iron and bile pigment)
  • contain haemoglobin to carry oxygen
• wbc

  • irregular shape
  • types: phagocyte(large) , lymphocyte (small)
  • phagocytes can squeeze themselves to pass through the capillary wall
  • colorless
  • produced in bone marrow and spleen
  • killed by germs or passed out of body in faeces
  • protect body against diseases by killing germs
• haemoglobin is broken down into iron to be reused to form new red blood cells, and bile pigment, a metabolic waste
• blood platelets

  • irregular, small
  • small pieces of cell fragments
  • colourless
  • no nucleus
  • produced in bone marrow
  • destructed in liver or spleen
  • involved in blood clotting to prevent further blood loss and entry of germs