Joints in Our Body

Per definition joints are locations where bones make contact with each other. they provide stability and allow movements. Arthritis, a commonly occurring condition is an inflammation of joint. Because their function is movement and support, the joints have been modified accordingly to serve the required function.

The joints are broadly classified into three categories. Each category has further subcategories

I. Fibrous Joints (Synarthroses – immovable articulations)
These include all those articulations in which the surfaces of the bones are in almost direct contact, fastened together by intervening connective tissue and in which there is no appreciable motion, as in the joints between the bones of the skull, excepting those of the mandible. There are four varieties of synarthrosis: sutura, gomphosis, and syndesmosis.

1. Sutures
2. Syndesmoses
3. Gomphoses

II. Cartilaginous Joints (Amphiarthroses or slightly movable articulations)

In these articulations the contiguous bony surfaces are either connected by broad flattened disks of fibrocartilage or hyaline growth cartilages. In this kind of joint the cartilage directly unites one bony structure to another ( bone – cartilage – bone). Cartilaginous joints are of two types-

1. Symphyses (Fibrocartilage)
2. Synchondroses (Hyaline Cartilage)

III. Synovial Joints (Diarthroses)

This class includes majority of the joints in the body. In a diarthrodial joint the ends of the bones are free to move in relation to each other because there is no cartilaginous tissue connects the adjacent bony surfaces. However the bone ends are indirectly connected to each other by joint capsule that covers and encloses the joint.

Depending upon plane(s) of movements, these joints are further classified into unaxial, biaxial and triaxial.

• Uniaxial

1. 1. Ginglymus (Hinge)
   2. Trochoid (Pivot)

• Biaxial

1. Condyloid
2. Saddle

• Triaxial

1. Plane or Gliding Joint
2. 2. Ball And Socket