Bones and Skeleton

Our bones and skeletal structure are the main requirements for our bodies to be able to move.

Without our bones, we would be more like a slug, just a ‘bag of blood, fluids, and skin’.


When we are born there are around 300 bones in the human skeleton. By the time we reach adulthood, some of these bones have fused together, so we only end up with 206 bones.

Bones are in a constant state of growth from the time we are born until around our mid-twenties. By the time we reach the age of thirty, our bone mass has achieved its maximum density.

The bones are incredible. If you break a bone it will try to repair itself and re-grow. Sometimes it doesn’t grow back in the right way so that’s why doctors put a splint or cast over the broken bone area to make sure they grow back properly.

The part of the human skeleton that is called the ‘axial’ skeleton has eighty bones in it. This includes the rib case, the vertebral column, and our skull. It helps us by spreading the weight of the head into the upper torso and allows us to keep our posture upright and straight.

It also helps in the balance of the body in the lower areas that are near our hips. The part of the skeleton that is called the ‘appendicular’ skeletal area contains 126 bones. This area includes the shoulder girdles (pectoral), the pelvic girdle, and the upper and lower limbs (arms and legs). The purpose of this area is for movement as well as to protect our organs.

There are six major functions for the human skeletal system: production of blood, for support, for protection, for movement, and for the storage of ions and use in the endocrine regulation.

Bones Facts for Kids

  • At birth, you have 270 bones in your body.
  • Adults have 206 bones as they fuse together as you get older.
  • You have 26 bones in your foot.
  • You have 27 bones in your hand.
  • Some bones help protect important organs in the body, for example, the rib cage helps to protect your heart, liver and lungs.
  • Our body has 5 different types of bones flat, short, long, irregular and sesamoid.
  • The inside of her bones is filled with marrow which is a soft tissue.
  • When bones are connected they form a joint. There are several different types of joints ball and socket, pivot, hinge and saddle joints.
  • The brain is protected by 8 different types of bones.
  • The longest bone in the body is the ‘femur’. This is the thigh bone and is also considered to be the strongest bone in the body.
  • The smallest bone in the body is actually located in your middle ear. It is called the ‘staples’ (or stirrup) and it’s only 0.11 inches (2.8 mm) long.
  • Like many parts of the body, our bones are constantly being worked and worn down and then re-made again. It takes seven years for the cells in the bones to regenerate so literally every 7 years we have a new bone.
  • There are 54 bones in your hands, fingers and wrists. This is the part of the body that has the most bones.
  • Although our teeth are part of the complete skeleton, they are not considered bones.


Male and female skeletons have a few differences. The male skeleton is typically larger and the female skeleton typically smaller. Female skeletons also have a different shape to the pelvic bone so that it is wider and angled to allow childbirth.

Almost all of our bones have a strong outer layer that is dense with an inside layer that is spongy and partially filled with air. The very center is flexible, soft tissue that is called the ‘bone marrow’.

4% of the human body mass is made up of bone marrow. It is the marrow that produces the red blood cells that we need to carry oxygen throughout our body. Bone marrow also creates important components of our lymphatic system in the production of lymphocytes. These help with our immune system.

Both calcium and vitamin D are important to help in keeping healthy, strong bones.

The parts of the skeleton where our bones meet are called ‘joints’. The joins allow movement, with the exception of the cranium joints. The bones are held in place at our joints with ligaments and muscles. Cartilage is another type of tissue that covers the surface of each bone join to keep the bones from rubbing against each other.