Question

Describe how the knee joint is adapted to prevent bones rubbing together

A) The knee joint is lined with a synovial membrane, which secretes synovial fluid to lubricate the joint and reduce friction.
B) The knee joint is made of rigid materials to prevent any movement and friction between the bones.
C) The knee joint has no adaptations to prevent bones from rubbing together.
D) The knee joint relies on muscle contractions to prevent bones from rubbing together.

Answer 1

The knee joint's bones are covered with articular cartilage and lubricated by synovial fluid to prevent friction, allowing smooth movement.

Step-by-step explanation:

The knee joint is adapted to prevent bones from rubbing together primarily through two key biological structures. First, the ends of the bones that form the knee joint, specifically the lower leg bone known as the tibia and the thighbone or femur, are covered with articular cartilage. This layer of hyaline cartilage provides a smooth, glass-like surface that facilitates movement and minimizes friction between bones during joint articulation. Second, the knee joint is surrounded by a synovial membrane that secretes synovial fluid, which serves as a lubricant inside the joint, further reducing friction and providing nourishment for the cartilage, which lacks its own blood supply. This joint, classified as a synovial joint, is capable of significant movement and is supported by surrounding ligaments for added stability.