fun skeleton

The skeleton is the rigid structure that serves as support and protection for the soft parts of a living being's body.

In humans and vertebrates, it is an endoskeleton (internal skeleton) composed of bones, cartilages, and ligaments. In other animals (such as insects or crustaceans), it is an exoskeleton (external shell).

The 4 main functions of the human skeleton

The skeleton does not just keep the body upright; it fulfills several vital roles:

1. Support and Shape: It forms the framework of the organism, maintaining vertical posture and giving shape to the body.
2. Protection: It houses the most fragile vital organs (the skull protects the brain, the rib cage protects the heart and lungs).
3. Movement: By serving as an anchor point for skeletal striated muscles, it acts as a lever system that allows for mobility through joints.
4. Metabolic and Blood Functions: * It stores essential minerals (notably calcium and phosphorus).
   • It produces blood cells (red blood cells, white blood cells, platelets) within the red bone marrow.

Composition in figures (Adult)

• 206 constant bones in adulthood (a newborn has approximately 270, but several fuse during growth).
• Divided into two main parts:
  • The axial skeleton: Skull, vertebral column, rib cage (central axis).
  • The appendicular skeleton: Upper limbs (arms), lower limbs (legs), as well as the girdles (scapular for the shoulder, pelvic for the hip) that connect them to the axis.

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