4.1 The Human Skeleton
The human skeleton is the body’s internal framework, giving us shape, protecting vital organs, enabling movement, and even producing blood cells. Without it, we’d be little more than a floppy pile of muscles and organs.
Adults typically have 206 bones, while babies are born with around 270. As we grow, some of these bones fuse together, particularly in the skull and spine. Interestingly, the smallest bone in the human body is the stapes, found in the ear and smaller than a grain of rice. In contrast, the largest bone is the femur, or thigh bone, which plays a key role in supporting our body weight and facilitating movement.
Functions of the Skeletal System
- Support: Holds the body upright and provides structure
- Protection: Shields vital organs (e.g., skull protects the brain, ribs protect the heart)
- Movement: Bones act as levers — muscles pull on bones to create movement
- Blood Cell Production: Bone marrow makes red and white blood cells
- Mineral Storage: Bones store calcium and other minerals needed for body function
Example: When you run, your leg bones support your weight, your joints help movement, and muscles pull on your bones to create motion.
