Final answer:
The suprapatellar bursa communicates with the joint cavity of the knee joint, helping to facilitate smooth movement of the tendon over the bone.
Step-by-step explanation:
The bursa that communicates with the joint cavity of the knee joint is the suprapatellar bursa. Bursae are fluid-filled sacs that serve to prevent friction between various tissues and the bones. Specifically, the suprapatellar bursa helps to separate the tendon of the large anterior thigh muscle from the distal femur just above the knee. This is important because the bursa allows for smooth movement of the tendon over the bone when the knee joint is in motion. The suprapatellar bursa is related to the knee joint, whereas other mentioned bursae, such as the prepatellar and infrapatellar, do not communicate with the knee joint cavity but serve different protective functions in the knee area.