1. Human Anatomy & Physiology FIFTH EDITION Elaine N. Marieb PowerPoint ® Lecture Slide Presentation by Vince Austin Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 8 Joints Part A

2. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Joints (Articulations) Weakest parts of the skeleton Articulation – site where two or more bones meet Functions Give the skeleton mobility Hold the skeleton together

3. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Classification of Joints: Structural Structural classification focuses on the material binding bones together and whether or not a joint cavity is present The three structural classifications are: Fibrous Cartilaginous Synovial

4. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Classification of Joints: Functional Functional classification is based on the amount of movement allowed by the joint The three functional class of joints are: Synarthroses – immovable Amphiarthroses – slightly movable Diarthroses – freely movable

5. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Fibrous Structural Joints The bones are jointed by fibrous tissues There is no joint cavity Most are immovable There are three types – sutures, syndesmoses, and gomphoses Figure 8.1a

6. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Fibrous Structural Joints Figure 8.1b

7. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Fibrous Structural Joints: Sutures Occur between the bones of the skull Comprised of interlocking junctions completely filled with CT fibers Bind bones tightly together, but allow for growth during youth In middle age, skull bones fuse and are called synostoses

8. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Fibrous Structural Joints: Syndesmoses Bones are connected by a fibrous tissue ligament Movement varies from immovable to slightly variable Examples include the connection between the tibia and fibula, and the radius and ulna

9. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Fibrous Structural Joints: Gomphoses The peg-in-socket fibrous joint between a tooth and its alveolar socket The fibrous connection is the periodontal ligament

10. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cartilaginous Joints Articulating bones are united by cartilage Lack a joint cavity Two types – synchondroses and symphyses Figure 8.2a

11. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cartilaginous Joints Figure 8.2b

12. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cartilaginous Joints Figure 8.2c

13. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cartilaginous Joints: Synchondroses A bar or plate of hyaline cartilage unites the bones All synchondroses are synarthrotic Examples include: Epiphyseal plates of children Joint between the costal cartilage of the first rib and the sternum

14. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Cartilaginous Joints: Symphyses Hyaline cartilage covers the articulating surface of the bone and is fused to an intervening pad of fibrocartilage Amphiarthrotic joints designed for strength and flexibility Examples include intervertebral joints and the pubic symphysis of the pelvis

15. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Synovial Joints Those joints in which the articulating bones are separated by a fluid-containing joint cavity All are freely movable diarthroses Examples – all limb joints, and most joints of the body

16. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Synovial Joints: General Structure Synovial joints all have the following: Articular cartilage Joint (synovial) cavity Articular capsule Synovial fluid Reinforcing ligaments Figure 8.3a

17. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Synovial Joints: Friction-Reducing Structures Bursae – flattened, fibrous sacs lined with synovial membranes and containing synovial fluid Common where ligaments, muscles, skin, tendons, or bones rub together Tendon sheath – elongated bursa that wraps completely around a tendon

18. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Synovial Joints: Friction-Reducing Structures Figure 8.4a, b

19. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Synovial Joints: Stability Stability is determined by: Articular surfaces – shape determines what movements are possible Ligaments – unite bones and prevent excessive or undesirable motion Muscle tone is accomplished by: Muscle tendons across joints are the most important stabilizing factor Tendons are kept tight at all times by muscle tone

20. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Synovial Joints: Movement Muscle attachment across a joint Origin – attachment to the immovable bone Insertion – attachment to the movable bone Described as movement along transverse, frontal, or sagittal planes

21. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Synovial Joints: Range of Motion Nonaxial – slipping movements only Uniaxial – movement in one plane Biaxial – movement in two planes Multiaxial – movement in or around all three planes

22. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Gliding Movements One flat bone surface glides or slips over another similar surface Examples – intercarpal and intertarsal joints, and between the flat articular processes of the vertebrae