 Hi, welcome to nursing school explained in this video on a quick review as to what happens to the physiology of a joint in osteoarthritis. So in a normal healthy joint we have two bones here in black and at the end of each bone we have cartilage that kind of cushions the impact of the bones and then in the joint capsule here in blue we also have synovial fluid that'll kind of help to lubricate the movement of the joints so the two bones don't rub against each other. In osteoarthritis what happens the because of major trauma or some repetitive micro trauma that joint space here gets narrowed so these bones are closer together the cartilage is much thinner than over here and then the in an attempt to repair the damage to the cartilage or the bone the body lays this extra layer of bone called also a bone spare on osteophyte on top here so these are kind of these little outgrowings of the bone that then become these jagged ad edges and so with that thinned joint space and less lubrication these bone surfaces can rub against each other and then in addition we have these extra jagged edges of new bone that form so that can cause a lot of pain there when the joint moves and that is the physiology of osteoarthritis for a full video check out my youtube channel where i go into signs and symptoms diagnostic tests and treatments about osteoarthritis as well