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Organizing the body

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					Human body

Organizing                                                     Systems
                                                                Organs and
                                                               tissues work in
the body                                                     teams to carry out
                                                            major tasks, like
Your cells and tissues are                                  transporting blood
organized into larger body                                  or processing food.
                                                            These teams are
parts called organs. In turn,                                 called systems.
your organs work together                                             The heart is the largest
to form body systems.                                                 organ in
                                                                      the blood system.
                                                                      It pumps blood around
               Kidney                                                 the body.
Heart


                        Brain




                                                                     The tubes that carry
Organs                                                               blood away from the
                                                                     heart are called
                                                                     arteries (shown in
An organ is a body part that                                         red).
does a specific job. Your heart’s
                                                                    The tubes that
job, for instance is to pump                                        carry blood back to
                                                                    the heart are called
blood. Kidneys clean blood.                                         veins (shown in
                                                                    blue).




                                                                Heart and blood
Organ transplant                                              Your heart, blood, and
If a vital organ stops working, doctors                       blood vessels make up
may replace it with an organ from another                     the blood system. It
      person. This is called a transplant.                   transports vital supplies
                                                            around your body.
10
                   Which body system makes your   stomach rumble?
                                                                             Organizing the body
Muscles                                                                       Other systems
Your muscle system is made
of tissues that move parts                                                    Some of your other
of your body by pulling                                                       important systems
on them or squeezing                                                          are shown in this list.
them. Your biggest
muscles all pull                                      Muscles change                  Breathing system: the
                                                      the position of your            main organs are your
on bones.                                             skeleton by pulling
                                                                                      lungs, which take in air.
                                                      different bones.
 Your fingers
 are moved by                                                                         Hormone system: this
 muscles in
 your arm.
                                                                                      uses powerful chemicals to
                                                                                      control your body and mood.
                                 The most powerful
                                 muscles are                                          Skin, hair, and nails:
                                 in your legs.
                                                                                      these form your body’s
                                                                                      protective covering.

                                                                                      Immune system: this
                                                                                      seeks and destroys germs
                                                                                      that get into your body.

                                                                                      Urinary system: this
                                         Skeleton                                     cleans blood and gets
                                                                                      rid of waste chemicals.
                                         Bones and
                                        joints make                                   Reproductive system:
                                       up the skeletal                                these are the organs that
                                        system, an                                    make babies.
                                       inner frame
                                      that supports                                  Digestive system
                                        the body.                                     Your digestive
                                                      A quarter of
                                                      your bones are                   organs break
                                                      in your feet.                    down food to
                            Nerves                                                     provide your
                            Your nervous system carries                                body with energy
                             electrical signals around                                and raw materials.
                                  your body. You need
                                      this system to see,                                     Your mouth is the first
 Signals shoot                                                                                part of the digestive
 along nerves to
                                         hear, think,
                                                                                               system.
 muscles,                                  and react.
 telling them
 when to pull.                                                                                    A long, twisting tube
                                                                                                  makes up your
                                                                                                   intestines, where
Senses, such as                                                                                     digested food is
touch, rely on                                                                                      absorbed.
nerve cells that
send signals to
your brain.                       Your brain is the
                                  nervous system’s
                                  control centre.
                   The digestive system.                                                                          11
                             12




                                                                                                                                                                                                                                                                           Skeleton
                                                           Skeleton                                                                                                                                Skull
                                                                                                                                                                                                                                   Smallest bone
                                                                                                                                                                                                                                     Around the same length
                                                           Your bones all join up to                                                                                                                                                 as a grain of rice, this
                                                                                                                                                                                                                                     is one of the smallest




                                                                                                                                                                                                                                                                           and
                                                           make a frame for your body                                                                                                                                               bones in your body. It
                                                           called the skeleton. This                                                                                                                                             lies deep inside your ear.




                                                                                                                                                                                                                                                                           bones
                                                                                                                                                                                                   Jaw bone
                                                           protects your insides, and
                                                           helps you move about.
How many ribs have you got?




                                                                                    Shoulder
                                                                                       blade                                                                                                                                                            A giraffe’s long
                                                                                                                                                                                                                                                        neck helps it to
                                                                                                                                                                                                                                                        eat leaves
                                                                            Each finger                                                                                                                                                                 off tall trees.
                                                                            has three bones,
                                                                            except for your
                                                                            thumb, which
                                                                            has two.




                                                           You have eight
                                                           small bones in
                                                           each wrist.




                                                           206 bones                                                                                                                                                                Neck bones
                                                           There are 206 bones                                                                               There are                                                              Did you know that you
                                                                                                                                                                                                           Rib
                                                                                                                                                           24 bones in                                                              have seven bones in your
                                                           in an adult skeleton.                                                                            your spine.
                                                                                                                                                                                                                                    neck, the same number
                                                           Over half of these are found in                                                                                                                                          as a giraffe? The top one
                                                           the hands and feet – the parts                                                                                                                                           allows you to move your
                                                           of your body that perform the                                                                                                                                            head up and down, the
                                                                                                                                                                                                                                    second lets you rotate it
                                                           most complicated movements.                                                                                                                     Pelvis                   from side to side.
                                                                                               The th




                                                                                                                                                                               Your tail bone is
                                                                                                                                                                               at the very
                                                                                                                                                                               bottom of your
                                                                                                     igh bone is the b




                                                                                                                                                                               spine.
 24, unless you are one of the rare people born with 26.




                                                                                                                                                                                                                                            Frogs have very short
                                                                                                                                                                                                                                            spines to withstand the
                                                                                                                                                                                                                                            strain of the huge leaps
                                                                                                                                                                                                                                            they take.

                                                                                                                                                                          Thigh bone
                                                                                                                       iggest




                                                                                                                                                                                                                    Snakes are
                                                                                                                                                                                                                                             A fish’s
                                                                                                                                                                                                                    incredibly bendy
                                                           Long lasting                                                                                                                                                                      spine allows it
                                                                                                                              and strongest in




                                                                                                                                                                                                                    thanks to many
                                                                                                                                                                                                                                             to bend its body from
                                                           Bone is a very hard                                                                                                                                      identical
                                                                                                                                                                                                                                             side to side so it can
                                                           material and one of the last                                                                                                                             vertebrae forming
                                                                                                                                                                                                                                             swim smoothly.
                                                                                                                                                                                                                    their long spines.
                                                           parts to rot away when a
                                                           body is buried. This woman
                                                           lived in the Stone Age, 5000                                                                                       Shin bone
                                                           years ago, but her bones
                                                           have survived until today.
                                                                                                                                               the body.




                                                                                                                                                                              Your ankle has
                                                                   Become                                                                                                     three larger
                                                                 an expert...                                                                                                 bones and four                               Other skeletons
                                                                                                                                                                              smaller ones.
                                                             on bone and cartilage,                                                                                                                                        Most animals have a
                                                                  pages 20-21                                                                                                                                              backbone and are called
                                                                                                                                                                                                                                                                           Skeleton




                                                                   on teeth,                                                                                              There are 54
                                                                                                                                                                          bones in your
                                                                                                                                                                                                                           “vertebrates”. Animals
                                                                  pages 84-85                                                                                             hands, and 52                                    with no spine, like spiders
                                                                                                                                                                          in your feet.
                                                                                                                                                                                                                              and bugs, are called
                             13




                                                                                                                                                                                                                              “invertebrates”.

				
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posted:10/10/2012
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