Anatomy of Joints 2023 PDF

Anatomy of Joints By Dr.Sayed Jahin Lecturer of anatomy and embryology How are bones connected together? By:- 1- ligaments: o A ligament is tough band of white , fibrous, slightly elastic tissues. oIt binds th...

Anatomy of Joints By Dr.Sayed Jahin Lecturer of anatomy and embryology How are bones connected together? By:- 1- ligaments: o A ligament is tough band of white , fibrous, slightly elastic tissues. oIt binds the bone ends together to prevent dislocation and excessive movements that may cause fracture 2- Joints: the contact between two bones or more to allow movements.  Joints Definition: The joint is called articulation or the point of contact between two bones or more Functions of joints Hold the skeletal bones together. Allow the skeleton some flexibility so gross movement can occur. Make bone growth possible.  Classification of Joints Joints can be classified according to function or structure 1-Functional: is determined by the degree of movement between the articulating bones. Synarthroses: immovable joints Amphiarthroses: slightly moveable joints Diarthroses: freely moveable joints 2-Structural: is determined by how the bones connect to each other Fibrous joints:generally immovable Cartilaginous joints:immovable or slightly moveable Synovial joints: freely moveable  Fibrous Joints 1. Bones are joined together byfibrous tissue/dense connective tissue, consisting mainly of collagen. 2.They are fixed (immobile) joints. 3. The fibrous joints are further divided into three types:-  1-Sutures: Bones are tightly bound by a minimal amount of fibrous tissue called sutures Examples: between the bones of the skull  2-Syndesmoses Bones are connected exclusively by ligaments or membrane Amount of movement depends on length of fibers Ex: Tibiofibular joint 3-Gomphoses It is a specialized fibrous joint restricted to fixation of teeth in alveolar sockets of the maxilla or mandible. The root of tooth is attached to the socket by periodontal ligament.  2-Cartilaginous Joints The Cartilage is a smooth elastic tissue, rubber-like padding that covers and protects the ends of long bones at the joints and nerves, and is a structural component of the rib cage, the ear, the nose, the bronchial tubes, the intervertebral discs, and many other body components. It has threetypes of cartilage: hyaline, fibrous, and elastic cartilage  In the cartilaginous joints the bones are joined by bands hyaline of cartilage. There are two types of cartilaginous joints: 1. Primary cartilaginous joints 2. Secondary cartilaginous joints 1-Primary cartilaginous joints 1.Temporary in nature joint 2.Disappear by ossification with age 3.Immobile joint 4.Consist of Plat of hyaline cartilage between the articulating bones Ex; 1- As between 1st rib & sternum (1st sternocostal joint) 2.Between epiphysis & diaphysis of all growing bones 3. Junctions of ribs with their costal cartilage 2-Secondary cartilaginous joint Permanent joint Present in the midline Limited in mobility The articulating bones are covered by thin layer of hyaline cartilage and are separated by white fibrocartilaginous disc. Ex. 1 Intervertebral disc. Symphysis pubis 2  3- Synovial joints Synovial joints are most mobile type of joints. They have the following characteristic features; 1. The articular surfaces of each bone are covered with hyaline cartilage which forms sliding surfaces for free movements. 2. There is a joint cavity between the articular surfaces filled with synovial fluid which lubricates the joint and nourishes the articular cartilage & minimizes the friction between the articular surfaces. 3. The joint is surrounded by an articular fibrous capsule and is lined internally by synovial membrane. 4. They are surrounded by ligaments & muscles which support them from outside.  Types Of Synovial Joint 1- Hinge joint One bone is convex cylinder connected to concavity of other bone Ex; Elbow – Ankle - Interphalangeal joints- Knee (modified hinge) Axis of Movements: occurred around transverse axis (flexion & extension). Knee Interphalangeal Elbow Ankle  2- Ball & Socket joint Is rounded head of one bone articulate with concave or cub Hip joint shaped socket of other bone. EX; Hip & shoulder Movements: all movements produced. Flexion & extension + abduction & adduction) + rotation  Plane joint (gliding)3- The articular surfaces are flat and the bones slides on other producing glidi movements Ex. Intracarpal and intratarsal joints Movements: Flexion & extension + abduction & adduction Intracarpal joints Intratarsal joints 4- Pivot joint Rounded or conical surface of one bone (central bony pivot) fit into a ring from fibrous tissues allowing rotation Ex; superior radio-ulnar joint Movements: only rotation. 5- Condylar joint: Consist of an oval-shaped end of one bone fitting into a similarly oval- shaped hollow of another bone. Ex; wrist joint Movements: flexion, extension, adduction & abduction 6-Saddle joints The ends of each bone resemble a saddle, with concave and convex portions that fit together. Examples: Thumb Joint, which can move back and forth and up and down, but more freely  Stability of synovial joints 1-The shape of articular surfaces: The ball and socket shape of the Hip joint is a good examples of the importance of bone shape to maintain joint stability. 2-Strength of the ligaments: They prevent excessive movement in a joint. Example: cruciate ligaments of the knee joint. 3- Tone of the surrounding muscles: In most joints, it is the major factor controlling stability. The short muscles around the shoulder joint keeps the head of the humerus in the shallow glenoid cavity.  Questions 5-Which of the following joints is ball & socket type 1-The knee joint is synovial joint of which type? A. Condyloid type A. Elbow B. Ball and socket B. Ankle C. Saddle type C. Hip D Hinge type 2-The. most mobile joints are: D. Knee A. Fibrous joints 6-Intracarpal joints are …... B. Synovial joints A. Ball and socket C. Primary cartilaginous D Condylar joints B. Saddle type. 3-The shoulder joint is synovial joint of which subtype? C. Gliding A. Condyloid type B. Ball and socket D. Hinge type C. Saddle type D Hinge type 7-The only example of saddle joint is:.4-The ankle joint is synovial joint of which subtype? A. Ball and socket A. Thumb B. Saddle type B. Knee C. Hinge type C. Wrist D. Fibrous D. Ankle 8-A good examples of the importance of bone shape to 11-The ankle joint is a gliding join maintain joint stability is: A. True A. Hip B. False B. Ankle 12-The synovial joints are supported by ligaments & C. Skull muscles D. Ribs A. True B. False 9-Which of the followings types of joints contains synovial fluid? 13- The synovial joints NOT contains synovial fluid A. Fibrous A. True B. False B. Primary cartilaginous C. Secondary cartilaginous 14-The superior radio-ulnar joint is Pivot type D Synovial A. True. 10-The elbow joint is synovial joint of which subtype? B. False A. Ball and socket 15 -The movement of the Pivot joint is only rotation B. Saddle type A. True C. Hinge type B. False D. Fibrous Thank you