Functions and Classification of Bones

This lesson covers the five functions of the skeleton and the four classifications of bones as required by the Edexcel GCSE PE specification (1PE0 — Topic 1: Applied Anatomy and Physiology). You need to know each function and bone type, be able to explain them clearly, and apply them to sporting examples.

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The Five Functions of the Skeleton

The Edexcel specification requires you to know the following five functions:

graph TD
    A["Functions of the Skeleton"] --> B["Support"]
    A --> C["Protection"]
    A --> D["Movement"]
    A --> E["Muscle Attachment"]
    A --> F["Blood Cell Production"]

    style A fill:#4a90d9,color:#fff
    style B fill:#e67e22,color:#fff
    style C fill:#e67e22,color:#fff
    style D fill:#e67e22,color:#fff
    style E fill:#e67e22,color:#fff
    style F fill:#e67e22,color:#fff

1. Support

The skeleton provides a rigid framework that supports the body and holds it upright against the force of gravity. Without the skeleton, the body would collapse.

• The vertebral column acts as the central pillar of support, holding the head, ribcage, and upper body upright.
• The pelvis supports the weight of the upper body and transfers it to the legs.
• The femur, tibia, and fibula support the body's weight when standing, walking, and running.

Sporting example: A gymnast performing a handstand relies on the bones of the arms (humerus, radius, ulna) and shoulder girdle (clavicle, scapula) to support the entire body weight in an inverted position.

2. Protection

The skeleton protects vital organs from damage. Bones are hard and rigid, forming a shield or cage around soft, delicate organs.

Bone(s)	Organ(s) Protected
Cranium	Brain
Vertebrae	Spinal cord
Ribs and sternum	Heart and lungs
Pelvis	Bladder, intestines, reproductive organs

Sporting example: In rugby, a tackle to the body is partly absorbed by the ribcage, which protects the heart and lungs from the impact.

Exam Tip: When answering questions about protection, always state both the bone and the organ it protects. For example: "The cranium protects the brain during a header in football."

3. Movement

The skeleton allows movement by acting as a system of levers. Bones act as rigid levers, joints act as pivots (fulcrums), and muscles provide the force.

• Muscles are attached to bones by tendons.
• When a muscle contracts, it pulls on the bone, causing movement at a joint.
• Different joints allow different types and ranges of movement.

Sporting example: When kicking a football, the quadriceps contracts and pulls on the tibia via the patella tendon, causing extension at the knee joint (a hinge joint). The femur and tibia act as levers.

4. Muscle Attachment

Bones provide surfaces for muscles to attach to. Without these attachment points, muscles could not pull on the skeleton to create movement.

• Muscles attach to bones via tendons at their origin (the fixed end, usually closer to the centre of the body) and insertion (the moving end, further from the centre of the body).
• Flat bones like the scapula have large surface areas that provide attachment for many muscles.
• The pelvis provides attachment for the powerful gluteus maximus, hip flexors, and quadriceps.

Sporting example: The scapula provides attachment for the deltoid muscle, which is essential for raising the arm when performing an overhead serve in badminton.

5. Blood Cell Production

Red blood cells and white blood cells are produced in the bone marrow — the soft tissue found inside certain bones (particularly flat bones and the ends of long bones). This process is called haematopoiesis.

• Red blood cells carry oxygen to working muscles — essential during exercise.
• White blood cells are part of the immune system and help fight infection.
• The ribs, sternum, pelvis, and vertebrae are particularly important sites for blood cell production.

Sporting example: A distance runner relies on a high volume of red blood cells to transport oxygen to the working muscles during a marathon. These red blood cells are produced in the bone marrow.

Exam Tip: Blood cell production is a function students often forget. If asked to list the functions of the skeleton, make sure you include it. Edexcel examiners specifically look for this.

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The Four Classifications of Bones

The Edexcel specification requires you to know the four types of bone and be able to give examples of each.