Assertion: knee's joint | /r/MadeOf | synovial fluid
Facets:
Source sentences:
text: This is like a bag that surrounds the joint containing synovial fluid to nourish and lubricate the knee allowing it to move smoothly and freely.
text: Joints fall into two basic categories: fibrous and cartilaginous joints, which contain connecting tissue and are mostly fixed in place, and synovial joints, which contain synovial fluid that enables movement as one bone smoothly slides over another.