anatomy Anatomy () is the branch of biology concerned with the study of the structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old science, having its ...

, a joint capsule or articular capsule is an envelope surrounding a synovial joint.eMedicine/Stedman Medical Dictionary Lookup!
Each joint capsule has two parts: an outer fibrous layer or membrane, and an inner synovial layer or membrane.

Membranes

Each capsule consists of two layers or membranes: * an outer (fibrous membrane, ''fibrous stratum'') composed of avascular white fibrous tissue * an inner ('' synovial membrane'', ''synovial stratum'') which is a secreting layer On the inside of the capsule, articular cartilage covers the end surfaces of the bones that articulate within that joint. The outer layer is highly innervated by the same nerves which perforate through the adjacent muscles associated with the joint.

Fibrous membrane

The fibrous membrane of the joint capsule is attached to the whole circumference of the articular end of each

bone A bone is a Stiffness, rigid Organ (biology), organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red blood cell, red and white blood cells, store minerals, provid ...

entering into the joint, and thus entirely surrounds the articulation. It is made up of

dense connective tissue Dense connective tissue, also called dense fibrous tissue, is a type of connective tissue with fibers as its main matrix element. The fibers are mainly composed of type I collagen. Crowded between the collagen fibers are rows of fibroblasts, fibe ...

. It's a long spongy tissue.

Clinical significance

Frozen shoulder Adhesive capsulitis, also known as frozen shoulder, is a condition associated with shoulder pain and stiffness. It is a common shoulder ailment that is marked by pain and a loss of range of motion, particularly in external rotation. There is a l ...

(adhesive capsulitis) is a disorder in which the

shoulder The human shoulder is made up of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder mak ...

capsule becomes inflamed.

Plica syndrome Plica syndrome is a condition that occurs when a ''plica'' (a vestigial extension of the protective synovial capsule of usually the knee) becomes irritated, enlarged, or inflamed. Cause This inflammation is typically caused by the plica being ca ...

is a disorder in which the synovial plica becomes inflamed and causes abnormal biomechanics in the knee.

Gallery

File:Gray201.png, Left clavicle. Inferior surface. File:Gray235.png, Right hip bone. External surface. File:Slide2bib.JPG, Right knee in extension. Deep dissection. Posterior view. File:Slide2cocc.JPG, Right knee in extension. Deep dissection. Posterior view.

References

External links