The Skeleton

Quick revise


  • Rigid frame for the rest of the body
  • Supports the soft tissue
  • Without the skeleton, we would collapse


  • Our body shape is due to the skeleton


  • Bones are tough
  • They protect delicate organs, like the brain, heart and lungs


  • There are many joints
  • Muscles, attached by tendons can move different bones

Making Blood Cells

  • Long bones contain bone marrow, which makes the new blood cells


Bones are formed by the ossification of cartilage. All bones start off as cartilage in the womb, and gradually turn into bone.

They have a tough outer layer called the periosteum.

Some types of bone are light, but tough. These tend to contain red marrow, where red blood cells are made.The marrow cavity contains yellow marrow, where white blood cells are made.

There are 4 different types of bone:

1. Long…like the femur

2. Short…like the carpels and tarsels

3. Flat…like some bones in the skull

4.  Irregular…like the vertebrae