JOINTS

1. JOINTS

2. JOINTS • Is an articulation, the place of union or junction between two or more bones or parts of bones of the skeleton • They show a variety of form and function i.e. – some joints have NO movements - some allow slight movements - some are freely movable

3. JOINTS • CLASSIFICATION OF JOINTS • 3 types of joints (according to the manner or type of material by which the articulating bones are united); • SYNOVIAL JOINTS • FIBROUS JOINTS • CARTILAGENOUS JOINT

4. JOINTS 1. SYNOVIAL JOINTS • Are movable joints containing lubricating liquid called synovial fluid. • Has 3 main parts of a synovial joint; i) JOINT CAVITY ii) Bone ends covered with articular cartilage (made of hyaline cartilage) iii) Articulating surfaces and joint cavity is enclosed by articular capsule • ARTICULAR CAPSULE – is fibrous capsule lined with synovial membrane.

5. SYNOVIAL JOINTS ASSOCIATED STRUCTURES; • ACCESSORY LIGAMENTS • Synovial joints are usually reinforced by accessory ligaments that are either separate (extrinsic) or are a thickening of a portion of the articular surface (intrinsic). • ARTICULAR DISCS - Some synovial joints have fibrocartilagenousarticular discs which are present when articular surfaces of bone are incongruous .

6. SYNOVIAL JOINTS • 6 types of synovial joints; (Classification is according to the shape of articulating surface and/or type of movement they permit) • PLANE JOINT • HINGE JOINTS • SADDLE JOINTS • CONDYLOID JOINTS • BALL AND SOCKET JOINT • PIVOT JOINT

7. SYNOVIAL JOINTS • PLANE JOINTS • Usually uniaxial • Permits gliding or sliding movements E.g. acromiumclavicular joint

8. SYNOVIAL JOINTS 2. HINGE JOINT • Uniaxial joint • Permits flexion and extension only E.g. Elbow joint

9. SYNOVIAL JOINTS 3. SADDLE JOINT - Biaxial • Saddle-shaped heads permit movement in two different planes. E.g. Carpometacarpal joint

10. SYNOVIAL JOINTS 4. CONDYLOID JOINT • Biaxial • Permit flexion and extension, abduction and adduction and circumduction. E.g. metacarpophalangeal joint

11. SYNOVIAL JOINTS 5. BALL AND SOCKET JOINTS • Multiaxial • A rounded head fits into a concavity which permits movement on several axis. E.g. Hip joint

12. SYNOVIAL JOINTS 6. PIVOT JOINT • Uniaxial joint • A round process of bone fits into a bony ligamentous socket allows rotation. E.g. Atlantoaxial joint.

13. SYNOVIAL JOINTS • BLOOD SUPPLY • Rich blood supply; blood vessels can be found in synovial membrane. • Also assists in the production of the synovial fluid (lubricating fluid in synovial joint) • NERVE SUPPLY • Provides proprioception sensation (information that provides awareness of movements and position of the body) • Pain fibers – rich distribution in fibrous capsule and associated ligament • Pain felt in sports injury • Synovial membrane is not sensitive – poor supply pain nerve fibers

14. JOINTS 2. FIBROUS JOINTS • Are united by fibrous tissue • The amount of movement depends on length of fibers uniting articulating bone EXAMPLES; i) SUTURES of skull ii) SYNDESMOSES of fibrous joint iii) GOMPHOSIS

15. FIBROUS JOINTS • SUTURES of skull

16. FIBROUS JOINTS ii) SYNDESMOSIS of fibrous joint • Unites bones with a sheet of fibrous tissue )either ligament or fibrous membrane) • Partially movable. E.g. A syndesmosis (bands of fibrous tissue) between tibia and fibula.

17. FIBROUS JOINTS iii) GOMPHOSIS (Dentoalveolarsyndesmosis) • is a synarthrosis (joint) that binds the teeth to bony sockets in the maxillary bone and mandible. The fibrous connection between a tooth and its socket is a periodontal ligament.

18. JOINTS 3) CARTILAGENOUS JOINTS • Are united by hyaline cartilage or fibrocartilage Example; • FIBROCARTILAGENOUS INTERVERTEBRAL DISCS • Between vertebrae • Consist of binding connective tissue that joints vertebrae together. FUNCTION; - Provides vertebral column (spine) with; a) Strength, b) Shock absorption c) Some degree of flexibility

19. CARTILAGENOUS JOINTS HYALINE cartilage joints between sternum and ribs (SYNCHONDROSIS) Growth regions of immature bones