A joint is the location at which two or more bones make contact. Bones are rigid organs that form part of the Endoskeleton of Vertebrates They function to move support and protect the various organs of the body produce ^[1] They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally. ^[2]

Classification

Depiction of an intervertebral disk, a cartilaginous joint.

Diagram of a synovial (diarthrosis) joint.

Joints are mainly classified structurally and functionally. Structural classification is determined by how the bones connect to each other, while functional classification is determined by the degree of movement between the articulating bones. In practice, there is significant overlap between the seven types of classifications.

Terms ending in the suffix -sis are singular and refer to just one joint, while -ses is the suffix for pluralization. In Grammar, a suffix (also postfix, ending) is an Affix which is placed at the end of a word

Structural classification

Structural classification names and divides joints according to how the bones are connected to each other. ^[3] There are three structural classifications of joints:

• fibrous joint - joined by fibrous connective tissue
• cartilaginous joint - joined by cartilage
• synovial joint - not directly joined

Functional classification

Joints can also be classified functionally, by the degree of mobility they allow:^[4]

• synarthrosis - permits little or no mobility. Fibrous joints are connected by dense connective tissue, consisting mainly of Collagen. In Zootomy, fibrous connective tissue ( FCT) is a type of Connective tissue which has relatively high Tensile strength, due to a relatively high Cartilaginous joints are connected entirely by Cartilage ( Fibrocartilage or Hyaline) Cartilage is a type of dense Connective tissue. It is composed of specialized cells called chondrocytes that produce a large amount of extracellular matrix Synovial joints (or diarthroses, or diarthroidal joints) are the most common and most moveable type of Joints in the human body A synarthrosis is a type of Joint which permits little or no mobility Most synarthrosis joints are fibrous joints. Fibrous joints are connected by dense connective tissue, consisting mainly of Collagen.
• amphiarthrosis - permits slight mobility. Amphiarthrosis is a type of continuous slightly movable Joint. Most amphiarthrosis joints are cartilaginous joints. Cartilaginous joints are connected entirely by Cartilage ( Fibrocartilage or Hyaline)
• diarthrosis - permits a variety of movements. Synovial joints (or diarthroses, or diarthroidal joints) are the most common and most moveable type of Joints in the human body All diarthrosis joints are synovial joints, and the terms "diarthrosis" and "synovial joint" are considered equivalent by Terminologia Anatomica. Synovial joints (or diarthroses, or diarthroidal joints) are the most common and most moveable type of Joints in the human body Terminologia Anatomica (TA is the international standard on human Anatomical terminology ^[5]

Biomechanical classification

Joints can also be classified based on their anatomy or on their biomechanical properties. According to the anatomic classification, joints are subdivided into simple and compound, depending on the number of bones involved, and into complex and combination joints:^[6]

1. Simple Joint: 2 articulation surfaces (eg. shoulder joint, hip joint)
2. Compound Joint: 3 or more articulation surfaces (eg. The glenohumeral joint, commonly known as the Shoulder joint, is a synovial Ball and socket joint and involves articulation between the radiocarpal joint)
3. Complex Joint: 2 or more articulation surfaces and an articular disc or meniscus (eg. In Human anatomy, the wrist is the flexible and narrower connection between the Forearm and the palm. The articular disk (or disc) is a thin oval plate of Fibrocartilage present in several Joints which separates synovial cavities This article is about the parts in the human kneeFor other uses of the term meniscus see Meniscus and lens (optics. knee joint)

Anatomical

The joints may be classified anatomically into the following groups:

1. articulations of hand
2. wrists
3. elbows
4. axillary articulations
5. sternoclavicular joints
6. vertebral articulations
7. temporomandibular joints
8. sacroiliac joints
9. hip joints
10. knee
11. articulations of foot

Arthritis

Main article: Arthritis

Arthritis and direct physical trauma to a joint are the causes of joint damage. The knee is the lower extremity Joint connecting the Femur, Patella, and the Tibia. The hands ( med / lat: manus pl manūs are the two intricate prehensile multi- Fingered body parts normally located at the end of each arm of a In Human anatomy, the wrist is the flexible and narrower connection between the Forearm and the palm. The elbow is the region surrounding the elbow-joint&mdashthe ginglymus or Hinge joint in the middle of the Arm. The sternoclavicular articulation is a double arthrodial Joint composed of two portions separated by an Articular disc. A vertebra (plural vertebrae) is an individual Irregular bone in the spinal or Vertebral column ( aka ischis a flexuous and flexible column The temporomandibular joint is the joint of the Jaw and is frequently referred to as TMJ. The sacroiliac joint is the Joint between the Sacrum, at the base of the spine, and the ilium of the Pelvis, which are joined by The knee is the lower extremity Joint connecting the Femur, Patella, and the Tibia. The foot is an Anatomical structure found in many Animals It is the terminal portion of a limb which bears weight and allows Locomotion. Arthritis (from Greek arthro-, joint + -itis, inflammation plural arthritides is a group of conditions involving damage to the Joints of the body Treatment of physical trauma is described here and in First aid. Arthritis is a group of conditions where there is damage caused to the joints of the body. Arthritis is the leading cause of disability in people over the age of 55.

There are many different forms of arthritis, each of which has a different cause. The most common form of arthritis, osteoarthritis (also known as degenerative joint disease) occurs following trauma to the joint, following an infection of the joint or simply as a result of aging. Osteoarthritis ( OA, also known as degenerative Arthritis, degenerative joint disease) is a clinical syndrome in which low-grade inflammation Furthermore, there is emerging evidence that abnormal anatomy may contribute to early development of osteoarthritis. Other forms of arthritis are rheumatoid arthritis and psoriatic arthritis, which are autoimmune diseases in which the body is attacking itself. Rheumatoid arthritis ( RA) is a chronic systemic autoimmune disorder that causes the Immune system to attack the Joints, where Psoriatic arthritis (also arthritis psoriatica, arthropathic psoriasis or psoriatic arthropathy) is a type of Inflammatory Arthritis Autoimmunity is the failure of an organism to recognize its own constituent parts as self, which results in an immune response against its own cells and tissues Septic arthritis is caused by joint infection. Septic arthritis is the invasion of a Joint by an Infectious agent which produces Arthritis. An infection is the detrimental Colonization of a host Organism by a foreign Species. Gouty arthritis is caused by deposition of uric acid crystals in the joint that results in subsequent inflammation. Gout (also called metabolic arthritis) is a disease created by a buildup of Uric acid. Uric acid (or urate) is an Organic compound of Carbon, Nitrogen, Oxygen and Hydrogen with the formula C5H4N4O3 Additionally, there is a less common form of gout that is caused by the formation of rhomboidal shaped crystals of calcium pyrophosphate. This form of gout is known as pseudogout.

References

See also

• Arthrology
• Kinesiology
• Replacement joint

External links

• Illustration of synovial joints at shockfamily.net
• Synovial joints Illustrations and Classification