tibia this is the shin bone or larger bone of the lower leg femur this is the thighbone or upper leg bone patella this is the kneecap cartilage a type of tissue that covers the surface of a bone at a joint cartilage helps reduce the friction of movement within a joint synovial membrane a tissue that lines the joint and seals it into a joint capsule the synovial membrane secretes synovial fluid a clear sticky fluid around the joint to lubricate it ligament a type of tough elastic connective tissue that surrounds the joint to give support and limits the joint s movement tendon a type of tough connective tissue that connects muscles to bones and helps to control movement of the joint meniscus a curved part of cartilage in the knees and other joints that acts as a shock absorber increases contact area and deepens the knee joint