The synovial joint, or diarthrosis, is one of the most common joints in mammals. It is also the joint that can be moved the most. This joint gains movement through the contacting point with the surrounding bones, which is common among most of the other joints. There are structural and functional differences that will distinguish the synovial joints from all of the rest of the joints. The main difference between the synovial joints and others is the presence of the capsules around the surface of the synovial joint, along with the presence of the lubricating fluid.
The synovial cavity is the space between the bones that contains synovial fluid. There are two key parts to the articular capsule. There is an outer part of the membrane that may contain ligaments and then there is the inner membrane that produces the lubrication and shock absorption for the joints, as well as the nourishing fluid. The final component of the synovial joint is the articular cartilage. This layer of cartilage is going to cover the bones of the synovial joint. It provides a smooth and slippery surface that does not fuse the joint bones together, but it allows them to absorb shocks and reduce the amount of friction you incur during movement.
There are seven different types of synovial joints, including: gliding joints, hinge joints, pivot joints, condyloid joints, saddle joints, ball and socket joints and compound joints. Each one of these joints is responsible for different functions within the body, but they all have the same main component and that is to have freedom of movement. Your joints are what enables you to be able to move and flex, so without all of these synovial joints we would not have all of the range in movement that we do right now.
Gliding joints can be found within the carpals of the wrist. They allow for gliding
and sliding movements. The hinge joints are found in the elbow and act in the same
manner as a door hinge, which allows the flexing and extending all in one plane.
Pivot joints are found in the distal radioulnar joint and the atlanto-
The wrist joint is referred to as the condyloid joint. This type of joint allows two bones to fit together when they have an odd shape, such as when one bone is concave and one is convex. You are able to have flexing, abducting and adduction movements. Saddle joints are found between the metacarpal and the carpal. They tend to resemble a saddle and allow the same freedom of movement as the condyloid joints.
The ball and socket joints are found within the shoulder and the hip. They allow you to have all of the movements with the exception of gliding. The compound joints are in the knee joint. The knee joint is composed of the condylar joint and the saddle joint. There are a lot of key elements within our joints and it is important that we understand them and how they work.