Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 2 The Nature, Use, and Varieties of Cartilage

The use of cartilage in joints

Another, and by no means the meanest use of cartilage, is that it provides the bones the opportunity to be in continual and frequent motion with less wear from friction. The meeting-points [cartilago articularis] of bones that are built for movement would, because of the dryness of bones, be easily damaged from the mutual contact unless the total area of contact where they come together and form a joint were separately covered by cartilage as by a casing, and this cartilage by its mixture of hardness and softness resisted the impact of the bones, and by yielding slightly undid the force of their contact. Cartilage is suited not only for reducing the friction of bones where they are worn by mutual contact, but it is seen to be so smooth and even that the head of a bone very readily turns in its socket, 6 and no roughness impedes this ease of motion as long as there is present a viscous and slippery liquid [synovia] similar to the lubricant with which we coat the pulleys on which ropes are turned. 7



Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 2 The Nature, Use, and Varieties of Cartilage