<em><u>-Joint capsule </u></em>
<em><u>-Synovial cavity </u></em>
A synovial joint is surrounded by a two layer<em><u> joint capsule</u></em> which encloses a fluid filled space called the <em><u>synovial cavity. </u></em>
<h3><u>Explanation; </u></h3>- <em><u>Synovial joint is a type of a joint that joins bone with fibrous joint capsule which is continuous with periosteum of the bones that have been joined. </u></em>
- <em><u>Joint capsule is an envelope that encloses the synovial joint and is also known as the articular capsule</u></em>.
- Joint capsule comprises of an outer fibrous layer membrane and the inner synovial layer membrane.
Dense connective tissue
The outer layer of this structure consists of <em><u>dense connective tissue</u></em> which is continuous with the periosteum of each bone
<h3><u>Explanation; </u></h3>- <em><u>The outer layer of the joint capsule is a fibrous membrane that is attached to the circumference of the articular end of each bone on the joint, therefore it surrounds the articulation. </u></em>
- This layer is made up of dense connective tissue which is irregular that is continuous with the periosteum of each bone in the joint. The tissue is a long spongy tissue
Ligaments
The outer layer may be reinforced by<em><u> ligaments </u></em>which are bundles of collagenous fibers. Some of these bundles are part of the capsule while other are located outside of the capsule.
<h3><u>Explanation; </u></h3>- <em><u>Ligaments are fibrous connective tissues that help in the articulation of bones to other bones. Ligaments are bundles of collagenous fibers which appear as a crisscross bands which attach bone to bone and help in the stabilization of joints. </u></em>
- <u><em>Ligaments surrounds a joint to give it support and also limits the movement of these joints. </em></u>Therefore when ligaments are damaged, the joints involved becomes unstable.
Accessory structure
By definition, the structures, such as some ligaments, that are located outside the capsule are called<em><u> accessory structures. </u></em>
<h3><u>Explanation; </u></h3>- <em><u>The synovial joint such as the knee joint contains a synovial cavity and dense, irregular connective tissue which makes the joint capsule normally associated with accessory ligaments</u></em>. These structures are called the accessory structures of the synovial joints.
- <em><u>The accessory structures are the pieces that help to strengthen and connect the joint. </u></em>They include the fibrocartilage, fat pads, tendons, Accessory, Extracapsular, intracapsular ligaments and the bursae.
Synovial membrane
The inner layer of the joint capsule is <em><u>the synovial membrane,</u></em> consisting of loose connective tissue.
<h3><u>Explanation; </u></h3>- <em><u>Synovial membrane is a connective tissue which lines the inner surface of the joint capsules in a synovial joint and the tendon sheath. </u></em>It may be described as a layer that lines the cavities of synovial joints bursae and the tendon sheaths.
- <u><em>The membrane functions to secrete the synovial fluid which lubricates the articulating joints.</em></u>
Synovial fluid
The inner lining of the joint capsule secretes a fluid called <em><u>synovial fluid. </u></em>This fluid is viscous, and moistens and lubricates the surfaces within the joint capsule
<h3><u>Explanation; </u></h3>- <em><u>Synovial fluid is a special type of viscous fluid that is secreted by the synovial membrane in a synovial joint such as knee joint whose function is primarily lubrication of the joint. </u></em>
- <em><u>The fluid contains special contents such as hyaluronan, lubricin and the interstitial fluid </u></em>which help in the reduction of friction between the articular cartilage of synovial joints when the joints are moving.