BP104T • Unit 2Topic 2 of 3⏱ 5 Min Read
2. Classification of Articulations (Joints)
💡 Core Concept & Clinical Context:
An articulation (joint) is a junction between two or more bones or cartilage. Joints are classified structurally based on binding material and presence of a joint cavity, and functionally based on degree of movement allowed.
Clinical Scenarios & Pharmacopoeial Examples:
1Structural & Functional Joint Classification Scheme
The three anatomical classes of joints.
Step-by-Step Breakdown:
•1. Fibrous Joints (Synarthroses - Immovable):
•• Bones joined by dense collagen fibers; zero joint cavity.
•• Types: Sutures (cranial bones), Syndesmoses (inferior tibiofibular joint), Gomphoses (peg-in-socket tooth in alveolar socket).
•2. Cartilaginous Joints (Amphiarthroses - Slightly Movable):
•• Bones joined by cartilage; zero joint cavity.
•• Types: Synchondroses (hyaline cartilage, e.g. epiphyseal growth plate, 1st rib to sternum) and Symphyses (fibrocartilage, e.g. Pubic symphysis, Intervertebral discs).
•3. Synovial Joints (Diarthroses - Freely Movable):
•• Characterized by: Hyaline articular cartilage, Fibrous articular capsule, Inner Synovial membrane secreting viscous hyaluronic acid synovial fluid, reinforcing ligaments.
•• Subtypes: Ball-and-Socket (shoulder, hip), Hinge (elbow, knee), Pivot (atlantoaxial joint), Condyloid (radiocarpal), Saddle (thumb carpometacarpal), Plane/Gliding (intercarpal).
📋Key Takeaways & Exam Highlights
- Synovial Fluid: Viscous, egg-white consistency fluid rich in Hyaluronic Acid and Lubricin that reduces friction and provides chondrocyte nutrition.
- Articular Cartilage: Avascular hyaline cartilage covering bone ends (damaged in Osteoarthritis).
🇮🇳 हिन्दी व्याख्या (2. Classification of Articulations (Joints))
जोड़ 3 प्रकार के होते हैं: फाइब्रस (अचल जैसे खोपड़ी के टांके), कार्टिलेजीनस (कम हिलने वाले जैसे रीढ़ की गद्दी), और साइनोवियल (पूरी तरह हिलने वाले जैसे घुटना, कंधा जिनमें साइनोवियल द्रव भरा होता है)।