Human Body


The Skeleton is the name given to the collection of bones that holds the rest of our body up. Our skeleton is very important to us. It does three major jobs.
  1. It protects our vital organs such as the brain, the heart and the lungs.

  2. It gives us the shape that we have. Without our skeleton, we would just be a blob of blood and tissue on the floor.

  3. It allows us to move. Because our muscles are attached to our bones, when our muscles move, they move the bones, and we move.

    When you were born, your skeleton had around 350 bones. By the time you become an adult, you will only have around 206 bones. This is because, as you grow, some of the bones join together to form one bone.

Our bones don't simply work on their own. The bones join together to form joints. The end of each bone is covered by a tough, smooth shiny substance called cartilage. The cartilage-coated bone-ends are kept apart by a thin film of slippery fluid that works like oil in a car. All of this is so your bones won't scratch and bump against each other when you move. Our bones are held together by strong stretchy bands called ligaments.

       Inside a Bone

Old bones are dead, dry and brittle. But in the body, bones are very much alive. They have their own nerves and blood vessels, and they do various jobs, such as storing body minerals.
A typical bone has an outer layer of hard or compact bone, which is very strong, dense and tough. Inside this is a layer of spongy bone, which is like honeycomb, lighter and slightly flexible. In the middle of some bones is jelly-like bone marrow, where new cells are constantly being produced for the blood.

How Many Bones?

  • Skull and upper jaw 21 bones
  • 3 tiny bones in each ear
  • Lower jaw (mandible)
  • Front neck bone (hyoid)
  • Backbone or spine (26 separate bones or vertebrae)
  • Ribs (12 pairs - same number for men and women)
  • Breastbone
  • Each upper limb has 32 bones: 2 in shoulder, 3 in arm, 8 in wrist, 19 in hand and fingers.
  • Each lower limb has 31 bones: 1 in hip (one side of pelvis), 4 in leg, 7 in ankle, 19 in foot and toes.

    Total = 206 bones