Chapter two Arthrology

1. Chapter two Arthrology Department of Anatomy 张正洪 博士/副教授

2. Classification There are two major types of articulations （or joints）. • Continuous joints/immovable joints • Fibrous joints : bones are united by fibrous connective tissue • Cartilaginous joints : bones are united by cartilage • Synosteosis • Discontinuous joints －synovial joints

3. Synovial joints Basic structures • Articular surface: covered byarticular cartilage • Articular capsule • Fibrous membrane • Synovial membrane • Articular cavity: containing a trace of synovial fluid; subatmospheric pressure in it

4. Accessory structures • Ligaments(lig.): extra- and intracapsular ligaments • Articular disc and articular labrum • Synovial fold andsynovial bursa

5. Movements of joints • Translation • Flexion and extension • Adduction and abduction • Rotation • Medial and lateral rotation • Pronation and supination • Circumduction

6. Classification of synovial joints • Uniaxial joints • Biaxial joints • Multiaxial joints

7. Articulations of Bones of Trunk The vertebral column consists of 24 vertebrae, the sacrum, and the coccyx.

8. Joints of the vertebral bodies Intervertebral discs between bodies of adjacent vertebrae, composedof: • Nucleus pulposus, an inner soft, pulpy, highly elastic structure (gelatinous core ) • Annulus fibrosus an outer fibrous ring consisting of fibrocartilage

9. Hemination of nucleus pulposus髓核脱出

10. Anterior longitudinal ligament • Maintains stability of the intervertebral disc and prevents hyperextension of the vertebral column Posterior longitudinal ligament • Prevents hyperflexion of the vertebral column and posterior protrusion of the discs

11. Joints of the vertebral arches • Ligamenta flava ― elastic ligament, unite laminae of adjacent vertebrae, and complete the posterior wall of vertebral canal; tend to prevent hyperflexion of the vertebral column

12. Interspinal ligament • Supraspinal ligament • Ligamentum nuchae • Intertansverse ligament • Zygapophysial joint

13. Atlantooccipital joint • Between superior articulating surfaces of atlas and occipital condyles • Supported by membrances and ligaments that join occipital bone and atlas • Action ― nodding of head, lateral tilting of head

14. Atlantoaxial joint • Three synovial joints between atlas and axis • Supported by ligaments • Action ― allow atlas (and head) to pivot on the axis and vertebral column

15. View of bertebral column as a whole Anterior view Posterior view Lateral view: • Cervical curvature • Thoracic curvature • Lumbar curvature • Sacral curvature

17. Movement of the vertebral column • flexion • extension • lateral flexion • Rotation • circumduction

18. Thoracic cage (thorax) Composition Bones― consists of twelve thoracic vertebraes, twelve pairs of ribs and costal cartilages, and sternum

19. Joints • Costovertebral joints • Joints of costal head • Costotransverse joints

20. Sternocostal joints • Sternocostal synchondrosis of first rib • Sternocostal joints • Interchondral joints: between costal cartilages 8, 9, and 10 to form the costal arch

21. General features of thoracic cage • Roughly cone-shape, narrow above and broad below, flattened from before-backwards, longer behind than in front • Inlet of thorax • Outlet of thorax • Infrasternal angle • Intercostal spaces

22. Function: • protects the organs in the thoracic cavity and upper abdominal cavity; • plays a vital role in the process of breathing Inspiration Expiration

23. Joints of skull • Continuous joints: sutures, synchondrosis or synosteosis

24. Temporomandibular joint • Articular surfaces • Capsule: thin and lax in front and behind; strengthened by the lateral ligament • Articular disc • Movement