• Question: are there more white blood cells or red?

    Asked by 12annrei to Clare, Mariana, Robert, Susanne on 21 Nov 2012. This question was also asked by sophie7.
    • Photo: Robert Insall

      Robert Insall answered on 21 Nov 2012:

      Hi Annrei

      There are more red blood cells. They’re relatively passive and do the big job (carrying oxygen).

      White blood cells have specific, different jobs like hunting down infections, and you don’t need so many of them.

      In leukaemias, the white blood cells overgrow. One of the bad things in leukaemia is that there are so many white blood cells that they crowd out the red blood cells; patients’ blood gets thin and doesn’t carry oxygen very well.

    • Photo: Susanne Muekusch

      Susanne Muekusch answered on 21 Nov 2012:

      Hi annrei,

      I agree with Robert. One more thing: White blood cells multiply on demand, the red blood cell number is usually stable (unless you do altitude training, but that’s a different story). While the red blood cells are always needed, the white blood cells are mainly needed during an infection. If your body is fighting an infection, the proportion of the white blood cells goes up.
      Therefore, the white blood cell count is a diagnostic measure if there is an infection ongoing in your body.

    • Photo: Mariana Campos

      Mariana Campos answered on 21 Nov 2012:

      Fun fact about blood cells: do you know that blood accounts for 7% of your body weight? And that red blood cells circulate in your body for around 120 days?

Comments

  • Photo: Clare

    Clare commented on :

    Apparently there are 2.4 million new red blood cells produced every second! And white blood cells only make 1% of your total blood volume while red blood cells make up 40 – 45% of blood volume!