The Skeletal System

Many unicellular organisms are unable to move by themselves. Instead, they are transported by air, water or other organisms. Although there are some unicellular organisms that have adapted to move independently. For example, bacteria can have one or multiple flagella, which allows them to move. Multicellular organisms require movement to function and survive.

The bone is a living tissue made up of cells with similar structures that work together to perform a shared function. There are 206 bones in the adult human skeleton, which provide structure and support to the body, protect vital organs, and enable movement. When a bone is broken, it has the ability to repair itself.

  • Calcium and other minerals make the bone strong, healthy and more flexible.

Below, you can see some of the major bones in the body.

Functions of the Skeleton

There are four primary functions of the skeleton:

  • Supporting the body
  • Protecting some of the vital organs in the body
  • Making blood cells
  • Helping the body to move


The skeleton supports the body and without this support, we would not be able to maintain an upright posture.


The skeleton protects our major organs.

For example:

  • The skull protects our brain
  • The backbone protects our spinal cord
  • The ribcage protects our heart and lungs

Making blood cells

There are different kinds of blood cells:

  • Red blood cells – Which carry oxygen around the body, in the blood
  • White blood cells – Which destroy harmful microorganisms in the body

Bone marrow is a soft, spongy tissue that produces red and white blood cells. Healthy bone marrow is important in the body and is located at the centre of certain large bones.


Bones play an important role in body movement, allowing the body to move as a whole or its individual parts. This is because they transmit the force from muscle contractions.