1. Joints

2. Joint (AKA Articulation) A point of contact between bones, between cartilage and bone or between teeth and bone

3. More Definitions Arthrology – The study of joints Kinesiology – study of the movement of the human body Rheumatology – the field of medicine devoted to joint diseases and related conditions

4. Classification of Joints Structural Classification – classified by the presence or absence of space between bones and the type of connective tissue that binds them together Functional Classification – related to the degree of movement it permits

5. Structural Classifications Fibrous Joints Cartilaginous Joints Synovial Joints

6. Functional Classifications Synarthrosis – immovable joint Amphiarthrosis – slightly moveable joint Diarthrosis – Freely movable joint

7. Fibrous Joints Bones are held together by fibrous connective tissue that is rich in collagen fibers No synovial cavity

8. Fibrous joints Permits little or no movement Suture – connect bones of the skull Syndesmosis – the distance between the 2 bones is greater than in a suture. Ex – between tibia and fibula Gomphosis – a cone shaped peg (tooth) fits into a cavity (socket)

9. Cartilaginous Joints The bones are held together by cartilage No synovial cavity

10. Cartilaginous Joints Allows little or no movement Synchondrosis – the connecting material is hyaline cartilage. Ex - epiphyseal plate Symphysis – ends of the bones are covered with articular cartilage but the cones are connected by a broad flat disc of fibrocartilage. Ex – pubic symphysis

11. Synovial Joints Bones have a synovial cavity and are united by a dense irregular connective tissue and accessory ligaments

12. Synovial joints Unique Characteristics: Synovial cavity Articular cartilage Articular capsule Fibrous capsule – outer layer (can form ligaments) Synovial membrane – areolar connective tissue with elastic fibers Synovial Fluid – secreted by the synovial membrane. It lubricates the joint, supplies nutrients and removes metabolic waste.

13. Synovial joints Accessory Ligaments – ligaments that are both inside and outside the articular capsule (ex – collateral ligaments of the knee) Menisci – pads of fibrocartilage that lie between articular surfaces of the bones and attach to the fibrous capsule Allows 2 bones of different shapes to fit more tightly Bursa – saclike structures between skin and bone or between tendons and bones situated to reduce friction

14. Torn Meniscus The tearing of the cartilage in the knee is common among athletes. Damaged cartilage can wear away the joint and eventually develop into arthritis. The surgical repair of the knee may be assisted by arthroscopy (a small lighted tool is inserted into the knee for visualization)

19. Types of Synovial Joints Planar – intercarpal, intertarsal, sternoclavicular Hinge – knee, elbow, ankle, fingers Pivot – atlanoaxial, radioulnar Condyloid – wrist and metacarpals Saddle – wrist and thumb Ball and Socket – shoulder, hips

20. SEE ALSO PAGE 163 IN THE TEXT BOOK FOR VERY GOOD ILLUSTRATIONS OF THE SYNOVIAL JOINTS