Bones

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Introduction

The human skeleton consists of 206 bones. Many of these move at joints, which in combination with over 600 skeletal muscles, enable the human body to perform a great variety of efficient and co-ordinated movements. The skeleton provides the system of levers required for human movement, and each joint is structured in the best possible way to suit its function.

Functions of the skeletal system

  1. To provide support for the body – the skeleton also gives the body its shape. The vital organs are attached to the inside of the skeleton, whilst muscles are mainly attached to the outside. Body shapes have been classified into somatotypes of which there are three: (a) Endomorphs are characterised by the roundness and softness throughout their whole body – they are often referred to as having pear-shaped bodies. (b) Ectomorphs are characterised by slim and lean builds – they are usually tall and skinny. (c) Mesomorphs are characterised by a body which has a high proportion of muscle – they usually have broad shoulders and narrow hips.
  2. To protect vital organs – the skeleton protects the delicate parts of the body. For example, the skull protects the brain; the vertebral column (spine) protects the spinal cord; the pelvis protects the reproductive organs and the bladder; the rib cage protects the heart and lungs.
  3. To produce blood cells. Red and white blood cells are produced in the marrow of the long bones (found in the centre of bones).
  4. To store minerals such as calcium.
  5. To provide movement – this is possible because the skeleton has many joints, and muscles which pull on the bones. The types of bone and joint determine what kind of movement can take place.

somatotypes