220 likes | 269 Views
Chapter 8. The Articular System. Introduction. Articulation: union between two or more bones Can be mobile or immobile Examples Sutures between skull bones Knee or elbow joint. The Classification of Joints: Structure and Function. Introduction.
E N D
Chapter 8 The Articular System
Introduction • Articulation: union between two or more bones • Can be mobile or immobile • Examples • Sutures between skull bones • Knee or elbow joint
Introduction • Joints are classified into three major groups based on: • Degree of movement allowed (function) • Type of material holding bones together (structure)
Synarthroses • No movement • Suture: bones connected by thin layer connective tissue (skull) • Syndesmosis: connected by ligaments between bones (radius and ulna) • Gomphosis: conical process in a socket (teeth)
Amphiarthroses • Slight movement • Symphysis: connected by disk of fibrocartilage (pubic symphysis) • Synchondrosis: connected by hyaline cartilage (growth plate between diaphysis and epiphyses)
Diarthroses or Synovial Joints • Free movement • Capsule with internal cavity • Capsule composition: fibrous cartilage, ligaments, tendons, muscle, synovial membranes • Functions: weight bearing and movement
Movements at Synovial Joints (cont’d.) • Flexion/Extension • Hyperextension: abnormal extension • Dorsiflexion/Plantar flexion • Abduction/Adduction • Rotation • Circumduction
Movements at Synovial Joints (cont’d.) • Supination/Pronation • Eversion/Inversion • Protraction/Retraction • Opposition/Reposition
The Six Types of Diarthroses or Synovial Joints (cont’d.) • Ball-and-socket • Widest range of movement • Movement can occur in all planes and directions • Shoulder • Hip
The Six Types of Diarthroses or Synovial Joints (cont’d.) • Hinge • Convex surface fits into concave surface • Flexion and extension only • Knee • Elbow
The Six Types of Diarthroses or Synovial Joints (cont’d.) • Pivot • Rotation in one plane • Atlas and axis (cervical spine) • Rotation of the head
The Six Types of Diarthroses or Synovial Joints (cont’d.) • Condyloid (ellipsoidal) • Oval-shaped condyle fits into elliptical cavity • Motion in two planes at right angles • Radius and carpal bones
The Six Types of Diarthroses or Synovial Joints (cont’d.) • Saddle • Motion in two planes at right angles • Permits opposition of the thumb
The Six Types of Diarthroses or Synovial Joints (cont’d.) • Gliding • Gliding motion • Intervertebral joints in spine
Animation – Synovial Joints Click Here to Play Synovial Joints Animation
Bursae (cont’d.) • Closed sacs prevent friction between tissues • Synovial membrane lining • Subcutaneous: between skin and underlying bony processes • Subfascial: between overlying muscles • Subtendinous: between overlying tendons or bony projections
Summary • Discussed the three types of joints (synarthroses, amphiarthroses, and diarthroses or synovial joints) • Described the movements possible at synovial joints • Named the six types of synovial joints • Discussed the functions and types of bursae