1. Joints Come in Many Types

2. Joints (Articulations) Functions of joints Classifying Joints: Functional or Structural Naming Movements of Bones Around Joints Types of Joints Based on Movement Selected Key Joints: Shoulder, Elbow, Hip, Knee Joint Injuries Chronic Joint Conditions: Arthritis

3. Joints (Articulations) Definition: site where two or more bones meet Functions of joints: Give skeleton mobility Hold skeleton together Joint classification Structural classification (material binding bones together and whether or not a joint cavity is present) Fibrous joints (sutures, syndesmoses, gomphoses) Cartilaginous Synovial Functional classification (amount of movement allowed by the joint) Synarthroses—immovable Amphiarthroses—slightly movable Diarthroses—freely movable

4. Fibrous Joints Bones joined by dense fibrous connective tissue No joint cavity Most are synarthrotic (immovable) Three types: Sutures Syndesmoses Gomphoses

5. Copyright © 2010 Pearson Education, Inc. Dense fibrous connective tissue Suture line (a) Suture Joint held together with very short, interconnecting fibers, and bone edges interlock. Found only in the skull. Rigid, interlocking joints containing short connective tissue fibers Allow for growth during youth In middle age, sutures ossify and are called synostoses

6. Copyright © 2010 Pearson Education, Inc. Fibula Tibia Ligament (b) Syndesmosis Joint held together by a ligament. Fibrous tissue can vary in length, but is longer than in sutures. Bones connected by ligaments (bands of fibrous tissue) Movement varies from immovable to slightly movable Examples: Synarthrotic distal tibiofibular joint Diarthrotic interosseous connection between radius and ulna

7. Copyright © 2010 Pearson Education, Inc. Root of tooth Socket of alveolar process Periodontal ligament (c) Gomphosis “Peg in socket” fibrous joint. Periodontal ligament holds tooth in socket. Peg-in-socket joints of teeth in alveolar sockets Fibrous connection is the periodontal ligament

8. Copyright © 2010 Pearson Education, Inc. Joints (Articulations) Definition: site where two or more bones meet Functions of joints: Give skeleton mobility Hold skeleton together Joint classification Structural classification (material binding bones together and whether or not a joint cavity is present) Fibrous joints (sutures, syndesmoses, gomphoses) Cartilaginous Synovial Functional classification (amount of movement allowed by the joint Synarthroses—immovable Amphiarthroses—slightly movable Diarthroses—freely movable

9. Cartilaginous Joints Bones united by cartilage No joint cavity Two types: Synchondroses Symphyses

10. Copyright © 2010 Pearson Education, Inc. Types of Cartilaginous Joints (all are synarthrotic- don’t move) (are strong, flexible amphiarthroses) Hyaline cartilage that covers articular surfaces

11. Copyright © 2010 Pearson Education, Inc. Joints (Articulations) Definition: site where two or more bones meet Functions of joints: Give skeleton mobility Hold skeleton together Joint classification Structural classification (material binding bones together and whether or not a joint cavity is present) Fibrous joints (sutures, syndesmoses, gomphoses) Cartilaginous Synovial Functional classification (amount of movement allowed by the joint Synarthroses—immovable Amphiarthroses—slightly movable Diarthroses—freely movable

12. Synovial Joints (Diarthrotic (freely movable)- most of body’s joints) Distinguishing features: 1.Articular cartilage: hyaline cartilage 2.Joint (synovial) cavity: small potential space 3.Articular (joint) capsule Outer fibrous capsule of dense irregular connective tissue Inner synovial membrane of loose connective tissue (type of integument) 4.Synovial fluid Viscous slippery filtrate of plasma + hyaluronic acid Lubricates and nourishes articular cartilage 5.Three possible types of reinforcing ligaments Capsular (intrinsic)—part of the fibrous capsule Extracapsular—outside the capsule Intracapsular—deep to capsule; covered by synovial membrane 6.Rich nerve and blood vessel supply Nerve fibers detect pain, monitor joint position and stretch Capillary beds produce filtrate for synovial fluid Bone A Bone B

13. Synovial Joints: Friction-Reducing Structures Bursae Flattened, fibrous sacs lined with synovial membranes Contain synovial fluid Commonly act as “ball bearings” where ligaments, muscles, skin, tendons, or bones rub together Inflammation from overuse or stress of joint causes bursitis Tendon sheath Elongated bursa that wraps completely around a tendon Inflammation from stress or overuse causes tendonitis

14. Synovial Joints: Stabilization, Movement, Range of Motion Stabilizing Factors Shapes of articular surfaces (minor role) Ligament number and location (limited role) Muscle tone, which keeps tendons that cross the joint taut Extremely important in reinforcing shoulder and knee joints and arches of the foot Movement Muscle attachments across a joint (will learn details when we learn muscles) Origin—attachment to the immovable bone Insertion—attachment to the movable bone Muscle contraction causes the insertion to move toward the origin Movements occur along transverse, frontal, or sagittal planes Range of Motion (don’t need to know) Nonaxial—slipping movements only Uniaxial—movement in one plane Biaxial—movement in two planes Multiaxial—movement in or around all three planes

15. Joints (Articulations) Functions of joints Classifying Joints: Functional or Structural Naming Movements of Bones Around Joints Types of Joints Based on Movement Selected Key Joints: Shoulder, Elbow, Hip, Knee Joint Injuries Chronic Joint Conditions: Arthritis

16. Movements at Synovial Joints 1.Gliding 2.Angular movements Flexion, extension, hyperextension Abduction, adduction Circumduction 3.Rotation Medial and lateral rotation 4.Angular movements: Flexion, extension, hyperextension Abduction, adduction 5. Other movements Dorsiflexion, plantar flexion Inversion, eversion Protraction, retraction Elevation, depression Opposition

17. Copyright © 2010 Pearson Education, Inc. Figure 8.5a Gliding (a) Gliding movements at the wrist

18. Copyright © 2010 Pearson Education, Inc. Figure 8.5b (b) Angular movements: flexion, extension, and hyperextension of the neck HyperextensionExtension Flexion

19. Copyright © 2010 Pearson Education, Inc. Figure 8.5c Hyperextension Flexion Extension (c) Angular movements: flexion, extension, and hyperextension of the vertebral column

20. Copyright © 2010 Pearson Education, Inc. Figure 8.5d Extension Flexion (d) Angular movements: flexion and extension at the shoulder and knee

21. Copyright © 2010 Pearson Education, Inc. Figure 8.5e Abduction Adduction (e) Angular movements: abduction, adduction, and circumduction of the upper limb at the shoulder Circumduction

22. Copyright © 2010 Pearson Education, Inc. Figure 8.5f Lateral rotation Medial rotation Rotation (f) Rotation of the head, neck, and lower limb

23. Copyright © 2010 Pearson Education, Inc. Figure 8.6a Supination (radius and ulna are parallel) (a) Pronation (P) and supination (S) Pronation (radius rotates over ulna)

24. Copyright © 2010 Pearson Education, Inc. Figure 8.6b Dorsiflexion Plantar flexion Dorsiflexion Plantar flexion (b) Dorsiflexion and plantar flexion

25. Copyright © 2010 Pearson Education, Inc. Figure 8.6c Eversion Inversion (c) Inversion and eversion

26. Copyright © 2010 Pearson Education, Inc. Figure 8.6d Protraction of mandible Retraction of mandible (d) Protraction and retraction

27. Copyright © 2010 Pearson Education, Inc. Figure 8.6e Elevation of mandible Depression of mandible (e) Elevation and depression

28. Copyright © 2010 Pearson Education, Inc. Figure 8.6f (f) Opposition Opposition