Copyright 2010, John Wiley & Sons, Inc. Chapter 7 Joints Copyright 2010, John Wiley & Sons, Inc.

Chapter 8 Joints of the Skeletal System Articulations - Junctions between bones Bind parts of skeletal system together Make bone growth possible Permit parts of the skeleton to change shape during childbirth Enable body to move in response to skeletal muscle contraction Copyright 2010, John Wiley & Sons, Inc. 8-2

Copyright 2010, John Wiley & Sons, Inc. Joints Classifications Functionally: by the degree of movement they permit Freely movable, Slightly movable, and Immovable Diarthrosis, Amphiarthrosis, and Synarthrosis Structurally: by their anatomy Fibrous, cartilaginous, or synovial Copyright 2010, John Wiley & Sons, Inc.

Functional Classification Types Diarthrosis: freely movable Most joints of the body All are synovial Amphiarthrosis: slightly movable Has greater amount of dense irregular connective tissue Radius-ulna Tibia-fibula Synarthrosis: immovable Pelvis, sutures, teeth Copyright 2010, John Wiley & Sons, Inc.

Types of Gliding Movements at Synovial Joints Flexion Decrease in angle between articulating bones Extension Increase in angle between articulating bones Anatomical position - body in full extension Hyperextension Bending beyond 180o degrees, ex: moving humerus backwards behind anatomical position Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Gliding Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Gliding Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Gliding Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Gliding Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Gliding Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Gliding Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Types of Angular Movements at Synovial Joints Abduction Movement of bone away from midline Adduction Movement of bone toward midline Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Angular Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Angular Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Angular Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Types of Rotation Movements at Synovial Joints Circumduction Movement of distal end in a circle Rotation Bone revolves around its own longitudinal axis Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Rotation Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Rotation Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Rotation Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Types of Special Movements at Synovial Joints Elevation Movement upward Depression Movement downward Protraction Movement forward Retraction Movement backward into anatomical position Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Special Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Special Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Types of Special Movements at Synovial Joints Inversion Move soles of feet medially Eversion Move soles laterally Dorsiflexion Bend foot toward dorsum (“stand on heels”) Plantar flexion Bend foot toward plantar surface (“stand on toes”) Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Special Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Special Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Special Movements at Synovial Joints Supination Movement of forearm so palms face forward or upward Pronation Movement of forearm so palms face backward or downward Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Special Movements at Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Structural Classification Based on what is between bones: Space (or not) Type of connective tissue present Types Fibrous joints - no cavity, dense irregular connective tissue Cartilaginous joints - no cavity, bones held together by cartilage Synovial joints - synovial cavity, dense irregular tissue of articular capsule, and often ligaments Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Fibrous Joints 3 Types Syndesmosis Suture Gomphosis Syndesmosis long fibers connect bones amphiarthrotic ex: distal ends of tibia and fibula Copyright 2010, John Wiley & Sons, Inc. 8-4

Copyright 2010, John Wiley & Sons, Inc. Fibrous Joints Suture between flat bones synarthrotic thin layer of connective tissue connects bones Gomphosis cone-shaped bony process in a socket tooth in jawbone synarthrotic Copyright 2010, John Wiley & Sons, Inc. 8-5

Copyright 2010, John Wiley & Sons, Inc. Fibrous Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Fibrous Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Fibrous Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Cartilaginous Joints Symphysis pad of fibrocartilage between bones Compressible “shock absorber” amphiarthrotic Ex: intervertebral discs & symphysis pubis Copyright 2010, John Wiley & Sons, Inc. 8-7

Copyright 2010, John Wiley & Sons, Inc. Cartilaginous Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Cartilaginous Joints Synchondrosis (synarthrosis) Example Epiphyseal (growth) plate connecting epiphysis and diaphysis of long bone Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Cartilaginous Joints Copyright 2010, John Wiley & Sons, Inc.

Synovial Joints: Structure Synovial cavity: space containing fluid Articular cartilage Covers ends of bones, absorbs shock Articular capsule Inner layer: synovial membrane that secretes synovial fluid (reduces friction, supplies nutrients) Outer layer: dense, irregular connective tissue diarthrotic Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Synovial Joints: Structure Copyright 2010, John Wiley & Sons, Inc.

Synovial Joints: Structure In some cases synovial joints include: Ligaments Joins a bone to another bone Menisci (cartilage discs) Articular fat pads Bursae Sacs made of synovial membranes containing fluid Located where friction can occur Examples: between skin-bone, tendons-bones, muscles-bones, ligaments-bones act as “ball bearings” Copyright 2010, John Wiley & Sons, Inc.

General Structure of a Synovial Joint Synovial fluid = viscous lubricating fluid within cavity Reduces friction between articular cartilages of 2 bones Provide “weeping lubrication” Nourish cartilage Contain phagocytes Copyright 2010, John Wiley & Sons, Inc.

Types of Synovial Joints Saddle joints One side saddle-shaped, other like a rider astride it Ex: trapezium to metacarpal-1 (thumb) Movements: F, E, ABD, ADD, ROT Ball-and-socket joints Ball-like surface into cuplike socket surface Ex: shoulder, hip Movements: F, E, ABD, ADD, CIR, ROT Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Types of Synovial Joints Condyloid joints Convex oval surface to concave oval surface Examples: wrist Movements: F, E, ABD, ADD Copyright 2010, John Wiley & Sons, Inc. 8-9

Copyright 2010, John Wiley & Sons, Inc. Types of Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Six Types of Synovial Joints Planar joints Articulating surfaces flat or slightly curved Examples: between carpals, tarsals, sternum-clavicle, scapula-clavicle Movements: gliding Hinge joints Convex-to-concave surfaces Examples: elbow, knee, ankle Movements: F and E only Copyright 2010, John Wiley & Sons, Inc.

Types of Synovial Joints Copyright 2010, John Wiley & Sons, Inc. 8-10

Copyright 2010, John Wiley & Sons, Inc. Types of Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Types of Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Types of Synovial Joints Pivot joints Rounded surface with ring formed by bone and ligament Examples: atlantoaxial joint (to turn head to say “no”) and radius-ulna for pronation-supination Movement: ROT Copyright 2010, John Wiley & Sons, Inc.

Types of Synovial Joints Copyright 2010, John Wiley & Sons, Inc. 8-11

Copyright 2010, John Wiley & Sons, Inc. Types of Synovial Joints Copyright 2010, John Wiley & Sons, Inc.

Details of a Synovial Joint: Knee Joint See slides 10a-d Ligaments Tibial and fibular collateral ligaments Anterior cruciate ligament (ACL): 70 % of knee injuries Posterior cruciate ligament (PCL) Menisci (medial and lateral) Fibrocartilage discs that increase stability of knee joint Bursae Arthroplasty Knee replacement: total or partial Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Knee Joint Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Knee Joint Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Knee Joint Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Knee Joint Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Aging of Joints Decrease in production of synovial fluid Thinning of articular cartilage Ligaments shorten and lose flexibility Influenced by genetic factors Copyright 2010, John Wiley & Sons, Inc.

Common Disorders of Joints Injuries Rotator cuff injury Separated shoulder Tennis elbow Dislocation of the radial head Knee injuries: swollen knee, rupture of tibial collateral ligaments, dislocated knee Rheumatism: rheumatoid arthritis, osteoarthritis Ligaments shorten and lose flexibility Influenced by genetic factors Copyright 2010, John Wiley & Sons, Inc.

Copyright 2010, John Wiley & Sons, Inc. Life-Span Changes Fontanels of skull harden in first 2 years Epiphyseal plates harden from ages 14-20 years Fibrocartilage loses water, decreases flexibility of intervertebral joints and knees Collagen changes causes stiffening beginning at age 30 Joint stiffness is an early sign of aging Regular exercise can prevent stiffness Fibrous joints first to strengthen over a lifetime Changes in symphysis joints of vertebral column diminish flexibility and decrease height Synovial joints lose elasticity Copyright 2010, John Wiley & Sons, Inc. 8-23

Copyright 2010, John Wiley & Sons, Inc. Clinical Application Sprains damage to cartilage, ligaments, or tendons associated with joints forceful twisting of joint Arthritis inflamed, swollen, painful joints Rheumatoid Arthritis Osteoarthritis Gout Bursitis inflammation of a bursa overuse of a joint Copyright 2010, John Wiley & Sons, Inc. 8-24

Copyright 2010, John Wiley & Sons, Inc. End of Chapter 7 Copyright 2010 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permission Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publishers assumes no responsibility for errors, omissions, or damages caused by the use of theses programs or from the use of the information herein. Copyright 2010, John Wiley & Sons, Inc.