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The stretchy bladder (Urinary system)

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The stretchy bladder (Urinary system) Powered By Docstoc
					Urinary system

The stretchy bladder
All day long, a small stream of                                             Nappy rash
                                                                            Babies sometimes get
urine trickles out of each kidney.                                          a rash under nappies.
It collects in an organ called the                                          This happens when
                                                                            urine mixes with
bladder, which stores the urine                                             poo and makes the
until you go to the toilet.                                                 skin sore.

                 Filling up
 Your bladder stretches as
   it fills up. This sends a
      signal to your brain,
      making you want to
             go to the toilet.




                                       X-ray of full bladder               X-ray of empty bladder


                                 Full stretch                                    The bladder’s
                                   An adult’s bladder stretches from             muscly wall
                                                                                 squeezes to push
                                      the size of a plum to the size             urine out.
                                         of a grapefruit and can hold
                                           about 500 ml (1 pint) of
                                             urine. Your bladder is
                                             about the size of an
                                              orange when it’s full.

                                                                     Inside the bladder
                                                                The bladder has a waterproof
                                                                  lining to stop it leaking. Urine
                                                               leaves through a tube called the
Grapefruit   Orange                                    Plum
                                                                    urethra, which is normally
                                                                     kept shut by two muscles.
92
                           How much urine do you make each day?
                                                                              The stretchy bladder
What is urine?
Urine is made of water and waste                  Camel urine
chemicals. The main waste is                      Camels can last for months without water so
urea, which your body makes                       they can survive in the driest deserts. They
                  when it breaks
                 down protein.
                                                  save water by making thick, syrupy urine
                 The colour of                    that is twice as salty as seawater.
                 urine depends
                 on how much
                 you drink. If
                 you drink lots of
                water, your urine
                will turn pale.
                                                                                                                      Camels store
                                                                                                                fat in their humps,
                                                                                                                which they use for
                                                                                                                             energy.
                 The yellow colour
                 comes from a
                 chemical that is
                 made when old
                                                    Bladder control
                 blood cells are
                 broken down.
                                                    In young children, the muscles that
                                                    open the bladder work automatically.
                   Tubes called                     As children get older, they




                                                                                                           l.
                   ureters bring
                                                    learn to control one of



                                                                                             ladder contro
                 urine from the
                        kidneys.
                                                    the muscles.

                                                                                               b
                                                                                            rn
                                                                                         ea




                                                          Potty training
                                                                                     l




                                                  Children gradually gain
                                                                                  to




                                                  control of their bladder
                                                                                     e
                                                                            lers hav




                                                   around the age of two,
                                                     but they still wet the
                      This muscle opens
                      automatically when          bed at night. By the age
                      the bladder is full.          of four, most children
                                                 can stay dry at night
                                                                         dd




                      Urethra
                                                             as well.
                                                                       To




                                     We have to learn
                                     to control this
                                     muscle.

                4-8 cupfuls, depending on how much you drink and sweat.                                                           93

				
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posted:10/10/2012
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