© 2014 pearson education, inc. powerpoint ® lecture presentations prepared by leslie hendon...

© 2014 Pearson Education, Inc.

PowerPoint® Lecture Presentations prepared byLeslie Hendon

University of Alabama, Birmingham

9Joints


I. Joints

► bones meet at joints (articulations)

► arthro = joint

► Joints can be classified by function or structure


A. Functional classification is based on amount of movement

1. Synarthroses—immovable

2. Amphiarthroses—slightly movable

3. Diarthroses—freely movable

B. Structural classification is based on: ► Material that binds bones together

► Presence or absence of a joint cavity

1. Fibrous

2. Cartilaginous

3. Synovial


Summary of Joint Classes


II. Fibrous Joints

A. bones are connected by fibrous connective tissue

B. do not have a joint cavity

C. most are immovable or slightly movable

► Sutures

► Syndesmoses

► Gomphoses


Sutures

A. bones are tightly bound by a minimal amount of fibrous tissue

B. occur only between the bones of the skull

C. allow bone growth so the skull can expand

► Synostoses—closed sutures


Syndesmoses

A. bones are connected exclusively by ligaments

e.g. tibio-fibular joint—immovable synarthrosis

e.g. interosseous membrane between radius and ulna

► diarthroses


Gomphoses

e.g. tooth in a socket

connecting ligament—the periodontal ligament


III. Cartilaginous Joints

A. bones are united by cartilage

B. lack a joint cavity

C. two types:

► Synchondroses

► Symphyses


Synchondroses

A. hyaline cartilage unites bones

e.g. epiphyseal plates of long bones

e.g. Joint between first rib and manubrium

Synchondroses

Bones united by hyaline cartilage

Epiphysealplate (temporaryhyaline cartilagejoint)

Sternum (manubrium)

Joint betweenfirst rib andsternum (immovable)


Symphyses

A. fibrocartilage unites bones

B. resists tension and compression

C. slightly movable joints that provide strength with flexibility► Intervertebral discs

► Pubic symphysis

Symphyses

Bones united by fibrocartilage

Pubic symphysis

Body of vertebra

Fibrocartilaginousintervertebral disc(sandwiched betweenhyaline cartilage)


IV. Synovial Joints

A. most movable type of joint

B. all are diarthroses

C. each contains a fluid-filled joint cavity

D. ends of opposing bones are covered with hyaline cartilage

► absorbs compression


V. General Structure of Synovial Joints

A. articular cartilage► ends of opposing bones are covered with hyaline cartilage

► absorbs compression

B. joint (articular) cavity► Unique to synovial joints

► Cavity holds a small amount of synovial fluid


C. Articular capsule—joint cavity is enclosed in a two-layered capsule

► Fibrous layer—dense irregular connective tissue, which strengthens joint

► Synovial membrane—loose connective tissue

- lines joint capsule and covers internal joint surfaces

- functions to make synovial fluid

D. Synovial fluid

► viscous fluid similar to raw egg white

► arises from capillaries in synovial membrane

► contains glycoprotein molecules secreted by fibroblasts

E. Reinforcing ligaments► extracapsular ligaments—outside the capsule

► intracapsular ligaments—internal to the capsule


Synovialmembrane

Fibrouslayer

Articular (hyaline)cartilage

Joint cavity (with synovial fluid)

Ligament

Articularcapsule

A typical synovial joint


Articularcapsule

A typical synovial joint


VI. How Synovial Joints Function

A. Are subjected to compressive forces

► Fluid is squeezed out as opposing cartilages touch

► Cartilages ride on the slippery film

B. Bursa - a flattened fibrous sac lined by a synovial membrane

C. Tendon sheath - an elongated bursa that wraps around a tendon

► closed bags of lubricant

► reduce friction between body elements


Subacromialbursa

Tendonsheath

Joint cavitycontainingsynovial fluid

Articularcartilage

Synovialmembrane

Fibrouslayer

Fibrous layerof articularcapsule


VII. Synovial Joints - Movements

A. Three basic types of movement1. Gliding—one bone across the surface of another

2. Angular movement—movements change the angle between bones

3. Rotation—movement around a bone's long axis


Gliding Joints

Gliding occurs between:

► carpals

► articular processes of vertebrae

► tarsals


Angular Movements

A. increase or decrease angle between bones

1. flexion & extension

2. abduction & adduction

3. circumduction


Extension

Flexion


Flexion

Extension


Flexion

FlexionExtension

Extension


Abduction

AdductionCircumduction


Rotation

A. involves turning movement of a bone around its long axis

B. only movement allowed between atlas and axis vertebrae

C. occurs at the hip and shoulder joints


Rotation

Lateralrotation

Medialrotation


Elevation—lifting a body part superiorly

Depression—moving the elevated part inferiorly

ElevationLifting a body partsuperiorly

DepressionMoving a body partinferiorly


Protraction—non-angular movement anteriorly

Retraction—non-angular movement posteriorly

ProtractionMoving a body part in theanterior direction

RetractionMoving a body part in theposterior direction


Supination—forearm rotates laterally

Pronation—forearm rotates medially

Pronation (P)Rotating the forearm so thepalm faces posteriorly

Supination (S)Rotating the forearm so thepalm faces anteriorly


Inversion—turns sole medially

Eversion—turns sole laterally

InversionTurning the sole of the footmedially

EversionTurning the sole of the footlaterally


Dorsiflexion—lifting the foot so it approaches the shin

Plantar flexion—depressing the foot, elevating the heel

DorsiflexionFoot so it approaches the shin

Plantar flexionElevating the heel


A. Plane joint

► intertarsal and intercarpal joints

► movements are non-axial

Flat articularsurfaces

Metacarpals

CarpalsGliding

Plane joint Nonaxial movement

VIII. Synovial Joints - Shape


B. Hinge joints

► Angular movement is allowed in one plane

► Elbow, ankle, and joints between phalanges


C. Pivot joints

► Proximal radio-ulnar joint


D. Condylar (or ellipsoid) joints

► Side to side—abduction–adduction

►Back and forth—flexion–extension


E. Saddle joints

► 1st carpometacarpal joint

► Allows opposition of the thumb


IX. Selected Synovial Joints

A. Shoulder (glenohumeral) joint

► The most freely movable joint lacks stability

► Muscle tendons contribute to joint stability


Coracoacromialligament

Subacromialbursa

Fibrous layer ofarticular capsule

Tendonsheath

Tendon ofbiceps

Glenoid labrum

Synovial cavitycontainingsynovial fluid

Articularcartilage

Synovial membrane

Fibrous layer ofcapsule

Frontal section through right shoulder joint


B. Elbow joint

► Allows flexion and extension

► Articulation of the humerus with the trochlear notch of the ulna

► Tendons of biceps and triceps brachii provide stability


Cadaver photo of medial view of right elbow

Ulnarcollateralligament

Radius

Coronoidprocessof ulna

Ulna

Humerus

Medialepicondyle

Articularcapsule

Anularligament


C. Wrist Joint

1. Radiocarpal joint—joint between the radius and proximal carpals

► allows for flexion, extension, adduction, abduction, and circumduction

2. Intercarpal joint—joint between the proximal and distal rows or carpals

► allows for gliding movement


Right wrist, anterior (palmar) view

Radius

radiocarpal

Thumb

Ulna

III III IV V

Intercarpal


D. Hip joint

► A ball-and-socket structure

► Head of femur articulates with acetabulum

► Stability from acetabulum and capsular ligaments

► Muscle tendons contribute somewhat to stability


Photo of the interior of the hip joint, lateral view

ligamentum teres

Acetabularlabrum

Synovial membrane

Headof femur

Articularcapsule (cut)


E. Knee joint

► Acts primarily as a hinge joint► Two fibrocartilage menisci occur within the joint cavity► Femoropatellar joint—shares the joint cavity


Sagittal section through the right knee joint

Lateralmeniscus

Tendon ofquadricepsfemoris

Suprapatellarbursa

Synovial cavity

Deep infrapatellarbursa

Patellar ligament

Posteriorcruciateligament

Anteriorcruciateligament


Anterior view of right knee

Lateralpatellarretinaculum

Fibularcollateralligament

Medialpatellarretinaculum

Tibialcollateralligament

Patellarligament


Osteoarthritis of the knee.


Clinical Application - Knee Injuries


F. Ankle joint

► A hinge joint between:

► Allows the movements dorsiflexion and plantar flexion only


Tibia

Metatarsophalangealjoint

Calcaneus

Interphalangealjoint

Ankle joint

Talonavicular joint

Cuneonavicular joint

Tarsometatarsal joint

Cadaver photo of ankle and foot, sagittal section

© 2014 pearson education, inc. powerpoint ® lecture presentations prepared by leslie hendon...

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