Are human bones rough or smooth?

Answer 1

The human skeleton consists of both fused and individual bones supported and supplemented by ligaments, tendons, muscles and cartilage. It serves as a scaffold which supports organs, anchors muscles, and protects organs such as the brain, lungs and heart.

The ends of some bones are smooth because they form joints. These are referred to as freely moving joints and they are the most common ones in our body. The ends of the bones are smooth because they are covered in hyaline cartilage, which is like soft marble. Inside the joint capsule that contains the ends of the bones with the hyaline cartilage there is a lubricant called synovial fluid that helps the joint move with minimal amount of friction.