ANAT LECT 5-6. joints 1 & 2.pptx
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Joints 1 &2 Anatomy unit Objectives Define joint. Classify joints on the basis of function, structure and axis of movements. Apply the knowledge of the different types of joints in understanding the movements taking place at these joints and its clinical significa...
Joints 1 &2 Anatomy unit Objectives Define joint. Classify joints on the basis of function, structure and axis of movements. Apply the knowledge of the different types of joints in understanding the movements taking place at these joints and its clinical significance. Define bursae. Enumerate the characteristic features of a typical synovial joint. Classify synovial joints. JOINTS Definition: articulation between two or more bones Types: according to the tissues in-between the bones 1. Fibrous 2. Cartilaginous 3. Synovial FIBROUS JOINTS (Synarthrosis) CHARACTERS: The articulating bones are separated from each other by fibrous tissue. No or very limited movement. TYPES OF FIBROUS JOINTS 1) Sutures: The 2 bones are connected together by small amount of fibrous tissue. Ossified in old age. Example: bones of the skull. TYPES OF FIBROUS JOINTS 2) Gomphoses Example: the root of the tooth is fixed to its bony socket by a fibrous membrane (periodontal ligament). Some movement while chewing TYPES OF FIBROUS JOINTS 3) Syndesmosis The 2 bones are connected together by excessive amount of fibrous tissue. Ex. Inferior tibiofibular joint and interosseous membrane between radius and ulna & tibia and fibula The most movable of fibrous joints CARTILAGENOUS JOINTS (Synchondrosis) Character The articulating bones are separated from each other by cartilage. They are slightly mobile. TYPES of CARTILAGENOUS JOINTS 1) Primary cartilaginous Bones are joined by hyaline cartilage Immobile Ex: epiphyseal plate of long bone and 1st rib with sternum Ossify with age TYPES of CARTILAGENOUS JOINTS 2) Secondary cartilaginous (symphysis) Two bones joined by fibrocartilage Ex: pubic symphysis and intervertebral discs Only slight amount of movement is possible Never ossify 1RY CARTILAGINOUS JOINT 2RY CARTILAGINOUS JOINT Intervenin Fibrocartilage Hyaline g cartilage Ossificatio Ultimately ossify Not ossify n (with age) (Permanent joint) (Temporary joint) Movement No movement Limited movement SYNOVIAL JOINTS Character These are freely movable joints. The articular surfaces are covered by articular hyaline cartilage. Joint surfaces are enclosed by a fibrous articular capsule Ligaments reinforce the joint Have a joint cavity filled with synovial fluid which lined by synovial membrane SYNOVIAL JOINTS Character Functions of the synovial fluid lubrication of the articular cartilage. Allows the joint to move freely. Helps in nutrition of the articular cartilage, menisci and articular discs. TYPES SYNOVIAL JOINTS Synovial joints are classified according to the following: Number of articulating bones. Number of axes around which movements take place. Shape of articulating surface. 1) According to number of articulating bones: 1. Simple joint: consists only of 2 articulating bones. 2. Compound joint: consists of more than 2 articulating bones. (e.g. elbow joint). 3. Complex joint: contains intracapsular articular disc (e.g. sternoclavicular joint), or menisci (e.g. knee joint). 2)According to number of axes of movement: 1. Uni-axial joint: the movements in one plane. 2. Bi-axial joint: the movements in two planes 3. Polyaxial joints: the movements in three planes or more. 1. Uni-axial joint: Hinge joints Pivot joints Shape articulating surfaces resemble the central bony pivot surrounded by a hinge of the door ring Example: Elbow joint Superior radio-ulnar joint interphalangeal joints. atlanto-axial joint Hinge Joints (elbow): 2. Bi-axial joint: Condyloid (ellipsoid) joints Saddle joints Shape An oval convexity is received in an One of the articulating surfaces is elliptical concavity concavo-convex., while the other surface is convexo-concave. Example: wrist joint carpometacarpal joint of the thumb. metacarpophalangeal joints 3. Poly-axial joint: Ball and socket joints Shape A rounded head is received into a cup-shaped concavity. Example: hip and shoulder joints 3)According to shape of articulating surfaces: Name:…… Example…….. Gliding movement (plane=smooth) Ex: intercarpal and intertarsal 3)According to shape of articulating surfaces: Name:…… Name:…… Example…….. Example…….. 3)According to shape of articulating surfaces: Name:…… Name:…… Example…….. Example…….. STABILITY OF JOINTS: 1. Shape of the articulating bones. 2. Contraction of the surrounding muscles 3. Strength of the surrounding ligaments. NERVE SUPPLY OF JOINTS: Hilton’s law: The motor nerve to a muscle tends to give a branch of supply to the joint, which the muscle moves and another branch to the skin over the joint. REFERENCE BOOK READING FOR SYNOVIAL JOINTS Clinical Anatomy by Regions, 10th edition, 2018 (LAWRENCE E. WINESKI). PAGES-42 to 43- LIGAMENTS AND BURSAE SDL-Types of Joints --- mainly synovial joints tables study https://next.amboss.com/us/ar ticle/Bo0zVS?q=types+of+joi
