BONES THAT MAINTAIN THEMSELVES

We have explained that there are joints where bones are connected to each other. For example, we can bend and straighten out our arms and legs thanks to the joints located at our elbows and knees. Although they move throughout our lives, these joints never need to be lubricated. Machines, however, need regular maintenance. For example, you have to lubricate the pedals or the chain of your bicycle from time to time because the amount of oil is reduced as they are used, which consequently restricts motion. Likewise, the joints between your bones are used all the time, yet you never have to lubricate them. Why is that? The answer to this question has been sought by scientists, who eventually discovered the following fact: in a joint, a tough, rubbery tissue called cartilage cushions the ends of the bones at contact points. There is a thin membrane lining the entire joint cavity which secretes a special fluid. As the bone exerts pressure on the joint, this fluid is forced out of the membrane and the joint becomes "lubricated". All these facts reveal to us that the human body is the result of an excellent design and superior creation. It is thanks to this excellent design that we can make many different movements easily and quickly. These features of the bones have been created by our Lord. Allah invites people to reflect on the creation of bones:
... Look at the bones—how We raise them up and clothe them in flesh... (Surat al-Baqara: 259)