Structural and Functional Classification of Joints Joint Structural Classification Functional Classification and Amount of Motion Allowed Structural Subcategory Intervertebral joint Shoulder (glenohumeral joint 9 Intercarpal joint Coronal suture Costochondral joint Atlantoaxial joint Tooth in its alveolus Interphalangeal joint 234 . Exploring Anatomy & Physiology in the Laboratory
The Correct Answer and Explanation is :
The classification of joints is based on two main criteria: structure (anatomical features) and function (range of motion). Here’s how these classifications apply to the specific joints you listed:
1. Intervertebral Joint
- Structural Classification: Cartilaginous
- Functional Classification: Amphiarthrosis (slightly movable)
- Explanation: The intervertebral joints are formed between the vertebrae of the spine. They are cartilaginous joints because they contain fibrocartilage in the intervertebral discs, which cushion and allow limited movement. These joints are classified as amphiarthrosis due to their slight movement.
2. Shoulder (Glenohumeral Joint)
- Structural Classification: Synovial
- Functional Classification: Diarthrosis (freely movable)
- Explanation: The glenohumeral joint, commonly known as the shoulder joint, is a synovial joint that allows extensive movement, such as flexion, extension, abduction, adduction, rotation, and circumduction. Its functional classification is diarthrosis, meaning it allows free movement.
3. Intercarpal Joint
- Structural Classification: Synovial
- Functional Classification: Diarthrosis (freely movable)
- Explanation: These are the joints between the small bones of the wrist. Intercarpal joints are synovial joints, providing the wrist with a range of motion. These joints are classified as diarthrosis due to their ability to move freely in various directions.
4. Coronal Suture
- Structural Classification: Fibrous
- Functional Classification: Synarthrosis (immovable)
- Explanation: The coronal suture is a fibrous joint between the frontal and parietal bones of the skull. It is classified as synarthrosis because it is immovable, providing stability to the skull.
5. Costochondral Joint
- Structural Classification: Cartilaginous
- Functional Classification: Synarthrosis (immovable)
- Explanation: The costochondral joints are the connections between the ribs and the cartilage of the sternum. These are cartilaginous joints and are classified as synarthroses because they do not allow movement.
6. Atlantoaxial Joint
- Structural Classification: Synovial
- Functional Classification: Diarthrosis (freely movable)
- Explanation: The atlantoaxial joint is located between the first and second cervical vertebrae (C1 and C2). It allows rotation of the head and is classified as a synovial joint with a diarthrosis functional classification, permitting free movement.
7. Tooth in its Alveolus
- Structural Classification: Fibrous
- Functional Classification: Synarthrosis (immovable)
- Explanation: The tooth in its alveolus (socket) is held in place by a fibrous joint known as a gomphosis. It is classified as synarthrosis due to the immovable nature of this connection.
8. Interphalangeal Joint
- Structural Classification: Synovial
- Functional Classification: Diarthrosis (freely movable)
- Explanation: The interphalangeal joints are located between the phalanges (bones of the fingers and toes). These joints are synovial, allowing movements such as flexion and extension, and are classified as diarthroses because of the significant range of motion.
Each of these joints is classified based on how they are structured anatomically and the degree of movement they allow, from immovable sutures to freely movable synovial joints.