Question

Identify and outline the structural and functional classifications of Joints. Include location and associated structures when describing these joints. Detail a synovial joint and how they function.

Answer 1

STRUCTURAL CLASSIFICATION OF JOINTS:-

1. Fibrous joints- Fibrous joints are connected by dense, tough connective tissue that is rich in collagen fibers. These fixed or immovable joints are typically interlocked with irregular edges. There are three types of fibrous joints:- SUTURES (cranium), SYNDESMOSIS (radio-ulnar and tibio-fibular joints) and GOMPHOSIS (dento-alveolar joint).
2. Cartilaginous joints- Cartilaginous joints are connected by fibrocartilage or hyaline cartilage. They allow more movement than fibrous joints but less than that of synovial joints. There are two types of cartilaginous joints:- SYMPHYSES (manubriosternal joint, between intervertebral discs, and the pubic symphysis) and SYNCHONDROSES (between epiphyseal plates).
3. Synovial joints- This is the most common and movable joint type in the body. Synovial joints can also be classified as nonaxial, monoaxial, biaxial, and multiaxial.

FUNCTIONAL CLASSIFICATION OF JOINTS:-

1. Synarthroses- These types of joints are immobile or allow limited mobility. This category includes fibrous joints such as suture joints (found in the cranium) and gomphosis joints (found between teeth and sockets of the maxilla and mandible).
2. Amphiarthroses- These joints allow a small amount of mobility. Most joints in this category
   include cartilaginous joints such as those found between vertebrae and the pubic symphysis.
3. Diarthrosis- These are the freely-movable synovial joints.

SYNOVIAL JOINT

• This is the most common and movable joint type in the body.

• These joints have a synovial cavity.

• Their bones are connected by dense irregular connective tissue that forms an articular capsule surrounding the bones’ articulating surfaces.

• A synovial joint connects bones with a fibrous joint capsule that is continuous with the bones’ periosteum. This joint capsule constitutes the outer boundary of a synovial cavity and surrounds the bones’ articulating surfaces.

• Synovial cavities are filled with synovial fluid.

• The various movements permitted by synovial joints are abduction, adduction, extension, flexion, and rotation.

• Synovial joints are further classified based on the different types of movement they provide, including plane joint, ball and socket joint, hinge joint, pivot joint, condyloid joint and saddle joint.

• Movements at synovial joints are classified as:-

1. Nonaxial (gliding): Found between the proximal ends of the ulna and radius.
2. Monoaxial (uniaxial): Movement occurs in one plane. An example is the elbow joint.
3. Biaxial: Movement can occur in two planes. An example is the wrist.
4. Multiaxial: Includes the ball and socket joints. An example is the hip joint.