Joints Development And Classification Anatomy

Joints

Question 1. Define joints and describe their classification.
Answer.

The joints are the junctions/meeting points between two or more bones. However, they can also be formed between bone and cartilage or between bone and tooth.

Joints Classification Joints are classified in two ways:

1. On the basis of the type of tissue (fibres or cartilage) binding the articulating bones or the presence or absence of a synovial cavity between the articular bones (structural classification).
2. On the basis of range and type of movement, they permit (i.e. functional classification).

Joints Structural classification

• Fibrous joint: It lacks the joint cavity and the articular bones are joined by the fibrous tissue. These joints are immovable or permit only slight movement.
• Cartilaginous joint: It also lacks the joint cavity and the articular bones are joined by the cartilage. These joints are immovable or permit only slight movement.
• Synovial joint: It has a joint cavity. The articular surfaces of the bones are covered by the articular (hyaline) cartilage. The articular bones are enclosed by a fibrous capsule. The joint cavity between the articular surfaces contains viscous synovial fluid. These joints are freely movable and permit a maximum degree of movement.

Joints Functional classification

• Immovable joints (synarthrosis), for example, fibrous joints (vide supra)
• Slightly movable joints (amphiarthrosis), for example, cartilaginous joints (vide supra)
• Movable joints (diarthrosis), for example, synovial joints (vide supra)