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The Blood

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The Blood Powered By Docstoc
					Biology 20                          Date:___________________         Name:___________________




     1. Fluids makes up 55 %
     2. The Fluids contains
              a. Proteins
              b. Nutrients
              c. Wastes
              d. Hormones
              e. Gases
              f. Sugars
     3. Cells and Platelets make up 45 %
     4. The three types of blood cells are
              a. Red blood cells
              b. White blood cells
              c. Platelets
     5. Dissolved glucose is around 0.72 grams per litre


        Shaped like biconcave disks

        Have no nucleus and lack most organelles

        Contain mostly hemoglobin, a protein that carries oxygen.

        Each protein contains a hemoglodin group in it that contains iron (a metal).

        Formed in the bone marrow

        Oxygen enters and leaves by diffusion. If the oxygen concentration in the surrounding
         tissue is low, oxygen leaves the red blood cell (e.g. near muscle cells). If the oxygen
         concentration in the surrounding tissue is high (e.g. in blood vessels in lungs), oxygen
         enters the red blood cell.

        In this way, red blood cells carry oxygen from the lungs to the body. Oxygen loading
         and unloading from red blood cells is a passive process – it happens randomly and no
         energy is expended.

        Carbon monoxide binds to haemoglobin much more strongly than oxygen does, so if
         you breathe in even a small amount of carbon monoxide, it prevents oxygen from
         getting to your tissue. This causes carbon monoxide poisoning, which can cause death


Biology 20 – The Blood                                                                    Page 1 of 3
J Garnier – 21-Aug-12
         due to lack of oxygen reaching your brain. Unfortunately, carbon monoxide is
         odourless, tasteless, and colourless, meaning you can’t tell you’re breathing it.


        Involved in immunity

        Several types that attack various types of invaders. Among these are lymphocytes.

              o T-lymphocytes coordinate the immune system and kill infected cells

              o B-lymphocytes produce antibodies, which are proteins that mark infected cells for
                killing. Some B-lymphocytes remain after an infection is gone so that if the same
                infection occurs again, you have a much faster immune response. This is why
                you can’t get many diseases twice (e.g. Chicken Pox).


        Small cell fragments, smaller than red blood cells

        Involved in clotting blood. Platelets contain factors that initiate blood clot formation.
         This stops bleeding if a blood vessel is damaged.

        Platelets will always form blood clots as soon as blood is removed from the body and
         start blocking wounds immediately. At the same time, proteins in the blood convert
         fibrinogen into fibrin and make a protein plug to prevent bleeding.

        The disease haemophilia is where some of the factors involved in blood clotting are
         missing and clots can’t form. This causes even minor wounds to bleed profusely.


        Fibrinogen is the inactive form of fibrin, which is activated when blood clots form


        Blood always contains glucose as this is required for all cells to perform cellular
         respiration to power their cellular processes.


        Many vitamins and minerals are dissolved in blood

        Carbon dioxide is dissolved as bicarbonate ions in blood. It enters blood from all cells as
         a waste product of cellular respiration.

        When blood reaches the lungs, the carbon dioxide diffuses out of the blood.




Biology 20 – The Blood                                                                         Page 2 of 3
J Garnier – 21-Aug-12
        1. Where in your body would blood have the highest concentration of oxygenated
           hemoglobin?




        2. Why does carbon monoxide kill you?




        3. How can a cell in your foot “breathe” even though it is not exposed to the air?




        4. If you don’t have enough platelets in your blood, what would happen?




        5. How do antibodies work?




        6. People who live at higher altitudes have more red blood cells than people who live at
           sea level. Why do you think this is? In this context, explain why winners of Olympic
           long distance races are disproportionately from countries with high mountain
           regions.




Biology 20 – The Blood                                                                       Page 3 of 3
J Garnier – 21-Aug-12

				
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