1. ELAINE N. MARIEB EIGHTH EDITION 5 Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings PowerPoint ® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University ESSENTIALS OF HUMAN ANATOMY & PHYSIOLOGY PART E The Skeletal System

2. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Joints  Articulations of bones  Functions of joints  Hold bones together  Allow for mobility  Ways joints are classified:  Functionally  Structurally

3. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Functional Classification of Joints  Synarthroses – immovable joints  Amphiarthroses – slightly moveable joints  Diarthroses – freely moveable joints

4. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Structural Classification of Joints  Fibrous joints  Generally immovable  Cartilaginous joints  Immovable or slightly moveable  Synovial joints  Freely moveable

5. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Fibrous Joints  Bones united by fibrous tissue  Examples  Sutures  Syndesmoses  Allows more movement than sutures  Example: distal end of tibia and fibula Figure 5.27a–b

6. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Cartilaginous Joints  Bones connected by cartilage  Examples  Pubic symphysis  Intervertebral joints Figure 5.27d–e

7. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Synovial Joints  Articulating bones are separated by a joint cavity  Synovial fluid is found in the joint cavity Figure 5.24f–h

8. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Features of Synovial Joints  Articular cartilage (hyaline cartilage) covers the ends of bones  Joint surfaces are enclosed by a fibrous articular capsule  Have a joint cavity filled with synovial fluid  Ligaments reinforce the joint

9. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings The Synovial Joint Figure 5.28

10. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Types of Synovial Joints Based on Shape Figure 5.29a–c

11. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Types of Synovial Joints Based on Shape Figure 5.29d–f

12. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Inflammatory Conditions Associated with Joints  Bursitis – inflammation of a bursa usually caused by a blow or friction  Tendonitis – inflammation of tendon sheaths  Arthritis – inflammatory or degenerative diseases of joints  Over 100 different types  The most widespread crippling disease in the United States

13. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Clinical Forms of Arthritis  Osteoarthritis  Most common chronic arthritis  Probably related to normal aging processes  Rheumatoid arthritis  An autoimmune disease – the immune system attacks the joints  Symptoms begin with bilateral inflammation of certain joints  Often leads to deformities

14. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Q: What causes the noise when you crack a joint? A: Escaping gases, movement and rough surfaces. Your joints can make a variety of sounds: popping, cracking, grinding, and snapping. The joints that "crack" are the knuckles, knees, ankles, back, and neck. There are different reasons why these joints "sound off". 1.Escaping gases: Scientists explain that synovial fluid present in your joints acts as a lubricant. The fluid contains the gases oxygen, nitrogen, and carbon dioxide. When you pop or crack a joint, you stretch the joint capsule. Gas is rapidly released, which forms bubbles. In order to crack the same knuckle again, you have to wait until the gases return to the synovial fluid. 2.Movement of joints, tendons and ligaments: When a joint moves, the tendon’s position changes and moves slightly out of place. You may hear a snapping sound as the tendon returns to its original position. In addition, your ligaments may tighten as you move your joints. This commonly occurs in your knee or ankle, and can make a cracking sound. 3.Rough surfaces: Arthritic joints make sounds caused by the loss of smooth cartilage and the roughness of the joint surface.

15. Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Q:Is joint cracking harmful? A: If you are feeling pain when your joints pop, than you should seek a health care professional. In terms of knuckle cracking, some studies show that knuckle cracking does not cause serious harm. Other studies show that repetitive knuckle cracking can do some damage to the soft tissue of the joint. It may also lead to a weak grip and a swelling hand.