ch 09 lecture presentation - Mission...

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PowerPoint® Lecture Slides prepared by Leslie Hendon University of Alabama, Birmingham

C H A P T E R

Copyright © 2011 Pearson Education, Inc.

Part 1

9 Joints


Joints

•  Rigid elements of the skeleton meet at joints or articulations

•  Greek root “arthro” means joint •  Structure of joints •  Enables resistance to crushing, tearing, and

other forces


Classifications of Joints •  Joints can be classified by function or structure •  Functional classification —based on amount of

movement •  Synarthroses—immovable; common in axial skeleton •  Amphiarthroses—slightly movable; common in axial skeleton •  Diarthroses—freely movable; common in appendicular skeleton (all

synovial joints) •  Structural classification ---based on

•  Material that binds bones together •  Presence or absence of a joint cavity •  Structural classifications include

•  Fibrous •  Cartilaginous •  Synovial


Classifications of Joints


Fibrous Joints

•  Bones are connected by fibrous connective tissue

•  Do not have a joint cavity •  Most are immovable or slightly movable •  Types •  Sutures •  Syndesmoses •  Gomphoses


Fibrous Joints

Figure 9.1

Dense fibrous connective tissue

Suture line

Root of tooth

Socket of alveolar process

Periodontal ligament

Fibula Tibia

Ligament

(a) Suture Joint held together with very short, interconnecting fibers,

and bone edges interlock. Found only in the skull.

(b) Syndesmosis Joint held together by a

ligament. Fibrous tissue can vary in length but is longer

than in sutures.

(c) Gomphosis Peg-in-socket fibrous joint. Periodontal ligament holds

tooth in socket.

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Cartilaginous Joints

•  Bones are united by cartilage •  Lack a joint cavity •  Two types •  Synchondroses •  Symphyses

Copyright © 2011 Pearson Education, Inc. Figure 9.2a

Synchondroses

•  Hyaline cartilage unites bones •  Epiphyseal plates •  Joint between first rib and manubrium

Epiphyseal plate (temporary hyaline cartilage joint)

Sternum (manubrium)

Joint between first rib and sternum (immovable)

(a) Synchondroses

Bones united by hyaline cartilage


Symphyses

•  Fibrocartilage unites bones; resists tension and compression

•  Slightly movable joints that provide strength with flexibility •  Intervertebral discs •  Pubic symphysis

•  Hyaline cartilage—present as articular cartilage


Symphyses

Figure 9.2b

Fibrocartilaginous intervertebral disc

Pubic symphysis

Body of vertebra

Hyaline cartilage

(b) Symphyses

Bones united by fibrocartilage


Synovial Joints

•  Most movable type of joint •  All are diarthroses •  Each contains a fluid-filled joint cavity


General Structure of Synovial Joints

•  Articular cartilage •  Ends of opposing bones are covered with

hyaline cartilage •  Absorbs compression

•  Joint cavity (synovial cavity) •  Unique to synovial joints •  Cavity is a potential space that holds a small

amount of synovial fluid

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•  Articular capsule—joint cavity is enclosed in a two-layered capsule •  Fibrous capsule—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



•  Synovial fluid •  A viscous fluid similar to raw egg white • A filtrate of blood • Arises from capillaries in synovial

membrane • Contains glycoprotein molecules secreted

by fibroblasts


General Structure of Synovial Joints •  Reinforcing ligaments

•  Often are thickened parts of the fibrous capsule •  Sometimes are extracapsular ligaments—located outside the

capsule •  Sometimes are intracapsular ligaments—located internal to the

capsule •  Richly supplied with sensory nerves

•  Detect pain •  Most monitor how much the capsule is being stretched

•  Have a rich blood supply •  Most supply the synovial membrane •  Extensive capillary beds produce basis of synovial fluid •  Branches of several major nerves and blood vessels


Periosteum

Ligament

Fibrous capsule Synovial membrane

Joint cavity (contains synovial fluid) Articular (hyaline) cartilage

Articular capsule

(a) A typical synovial joint


Figure 9.3a


Synovial Joints with Articular Discs

•  Some synovial joints contain an articular disc •  Occur in the temporomandibular joint and at

the knee joint •  Occur in joints whose articulating bones have

somewhat different shapes


How Synovial Joints Function

•  Synovial joints—lubricating devices •  Friction could overheat and destroy joint

tissue •  Are subjected to compressive forces

• Fluid is squeezed out as opposing cartilages touch • Cartilages ride on the slippery film

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Bursae and Tendon Sheaths

•  Bursae and tendon sheaths are not synovial joints •  Closed bags of lubricant •  Reduce friction between body elements

•  Bursa—a flattened fibrous sac lined by a synovial membrane

•  Tendon sheath—an elongated bursa that wraps around a tendon


Bursae and Tendon Sheaths

Figure 9.5a, b

Acromion of scapula

Joint cavity containing synovial fluid

Synovial membrane Fibrous capsule

Humerus

Hyaline cartilage

Coracoacromial ligament Subacromial bursa Fibrous articular capsule

Tendon sheath

Tendon of long head of biceps brachii muscle (a) Frontal section through the right shoulder joint

Coracoacromial ligament Subacromial bursa

Cavity in bursa containing synovial fluid

(b) Enlargement of (a), showing how a bursa eliminates friction where a ligament (or other structure) would rub against a bone

Humerus resting

Humerus moving

Bursa rolls and lessens friction.

Humerus head rolls medially as arm abducts.


Movements Allowed by Synovial Joints

•  Three basic types of movement •  Gliding—one bone across the surface of

another •  Angular movement—movements change the

angle between bones •  Rotation—movement around a bone's long

axis


Gliding Joints

•  Flat surfaces of two bones slip across each other

•  Gliding occurs between •  Carpals •  Articular

processes of vertebrae

•  Tarsals

Figure 9.6a

Gliding

(a) Gliding movements at the wrist


Angular Movements

•  Increase or decrease angle between bones •  Movements involve •  Flexion and extension •  Abduction and adduction •  Circumduction


Angular Movements

Figure 9.6b

(b) Angular movements: flexion and extension of the neck

Extension

Flexion

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Angular Movements

Figure 9.6c

Flexion

Extension

(c) Angular movements: flexion and extension of the trunk Copyright © 2011 Pearson Education, Inc.

Angular Movements

Figure 9.6d

Extension

Extension

Flexion

Flexion

(d) Angular movements: flexion and extension at the shoulder and knee


Angular Movements

Figure 9.6e

PLAY Movement of the pectoral girdle (a)

Abduction

Adduction

(e) Angular movements: abduction, adduction, and circumduction of the upper limb at the shoulder

Circumduction


Rotation

•  Involves turning movement of a bone around its long axis

•  The only movement allowed between atlas and axis vertebrae

•  Occurs at the hip and shoulder joints


Rotation

Lateral rotation Medial rotation

(f) Rotation of the head, neck, and lower limb

Rotation

Figure 9.6f Copyright © 2011 Pearson Education, Inc.

Special Movements

•  Elevation—lifting a body part superiorly •  Depression—moving the elevated part

inferiorly

Figure 9.7a

Elevation of mandible

Depression of mandible

(a) Elevation Lifting a body part superiorly

Depression Moving a body part inferiorly

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Special Movements

•  Protraction—nonangular movement anteriorly

•  Retraction—nonangular movement posteriorly

Figure 9.7b

Protraction of mandible

Retraction of mandible

(b) Protraction Moving a body part in the anterior direction

Retraction Moving a body part in the posterior direction


Special Movements

•  Supination—forearm rotates laterally, palm faces anteriorly

•  Pronation—forearm rotates medially, palm faces posteriorly •  Brings radius across the ulna


Special Movements

Figure 9.7c

Supination (radius and ulna are parallel)

(c) Pronation (P) Rotating the forearm so the palm faces posteriorly

Supination (S) Rotating the forearm so the palm faces anteriorly

Pronation (radius rotates over ulna)


Special Movements

•  Opposition—thumb moves across the palm to touch the tips of other fingers

Figure 9.7d

(d) Opposition Moving the thumb to touch the tips of the other fingers

Opposition


Special Movements

•  Inversion and eversion •  Special movements at the foot •  Inversion—turns sole medially • Eversion—turns sole laterally


Eversion Inversion

(e) Inversion Turning the sole of the foot medially

Eversion Turning the sole of the foot laterally

Special Movements

Figure 9.7e

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Special Movements

•  Dorsiflexion and plantar flexion •  Up-and-down movements of the foot •  Dorsiflexion—lifting the foot so its superior

surface approaches the shin •  Plantar flexion—depressing the foot, elevating

the heel


Special Movements

Figure 9.7f

Dorsiflexion

Plantar flexion

(f) Dorsiflexion Lifting the foot so its superior surface approaches the shin

Plantar flexion Depressing the foot elevating the heel


Synovial Joints Classified by Shape

•  Plane joint •  Articular surfaces are flat planes •  Short gliding movements are allowed •  Intertarsal and intercarpal joints • Movements are nonaxial • Gliding does not involve rotation around

any axis


Plane Joint

Figure 9.8a

(a) Plane joint

Gliding

Metacarpals

Carpals

Nonaxial movement



•  Hinge joints •  Cylindrical end of one bone fits into a trough

on another bone •  Angular movement is allowed in one plane •  Elbow, ankle, and joints between phalanges •  Movement is uniaxial—allows movement

around one axis only


Hinge Joint

Figure 9.8b

(b) Hinge joint

Medial/ lateral axis

Flexion and extension

Humerus

Ulna

Uniaxial movement

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•  Pivot joints •  Classified as uniaxial – rotating bone only

turns around its long axis •  Examples • Proximal radioulnar joint •  Joint between atlas and axis


Pivot Joint

Figure 9.8c

(c) Pivot joint

Ulna

Vertical axis

Rotation Radius



•  Condyloid joints •  Allow moving bone to travel • Side to side—abduction-adduction • Back and forth—flexion-extension

•  Classified as biaxial—movement occurs around two axes


Condyloid Joint

Figure 9.8d

(d) Condyloid joint


Adduction and abduction


Metacarpals

Phalanges

Anterior/ posterior axis

Biaxial movement



•  Saddle joints •  Each articular surface has concave and

convex surfaces •  Classified as biaxial joints •  1st carpometacarpal joint is a good example • Allows opposition of the thumb



Figure 9.8e

(e) Saddle joint

Anterior/ posterior axis


Adduction and abduction

Metacarpal 1

Trapezium Flexion and extension

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•  Ball-and-socket joints •  Spherical head of one bone fits into round

socket of another •  Classified as multiaxial—allow movement in

all axes • Shoulder and hip joints are examples


Ball-and-Socket Joint

Figure 9.8f

PLAY Movement of the glenohumeral joint (a)

(f) Ball-and-socket joint

Medial/lateral axis

Anterior/posterior axis Vertical

axis

Rotation Adduction and abduction


Scapula

Humerus

Multiaxial movement


Factors Influencing Stability of Synovial Joints •  Articular surfaces •  Shapes of articulating surfaces determine

movements possible •  Seldom play a major role in joint stability • Exceptions that do provide stability • Hip joint, elbow joint, and ankle


Factors Influencing Stability of Synovial Joints •  Ligaments

•  Capsules and ligaments prevent excessive motions •  On the medial or inferior side of a joint – prevent excessive abduction •  Lateral or superiorly located—resist adduction •  Anterior ligaments—resist extension and lateral rotation •  Posterior ligaments—resist flexion and medial rotation

•  The more ligaments, usually stronger and more stable •  Muscle tone

•  Helps stabilize joints by keeping tension on tendons •  Is important in reinforcing:

•  Shoulder and knee joints •  Supporting joints in arches of the foot


Selected Synovial Joints

•  Sternoclavicular joint •  Is a saddle joint •  Four ligaments surround the joint

•  Anterior and posterior sternoclavicular ligaments •  Interclavicular ligament •  Costoclavicular ligament

•  Performs multiple complex movements



Figure 9.9

Anterior sternoclavicular ligament and joint capsule

Interclavicular ligament

Articular disc

Manubrium of sternum

Costal cartilage of 1st rib

Costoclavicular ligament

Clavicle

(a) Sternoclavicular joint, anterior view

Depression Protraction

Elevation Retraction Posterior rotation

(b) Sternoclavicular movements

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•  Temporomandibular Joint •  Is a modified hinge joint •  The head of the mandible articulates with the

temporal bone •  Lateral excursion is a side-to-side movement •  Two surfaces of the articular disc allow

•  Hinge-like movement •  Gliding of superior surface anteriorly

Copyright © 2011 Pearson Education, Inc. Figure 9.10

The Temporomandibular Joint

Zygomatic process

Mandibular fossa Articular tubercle

Infratemporal fossa

External acoustic meatus

Articular capsule

Ramus of mandible

(a) Location of the joint in the skull

Lateral ligament

Articular capsule

Mandibular fossa

Articular disc

Articular tubercle

Superior joint cavity

Inferior joint cavity

Mandibular condyle

Ramus of mandible

Synovial membranes

(b) Enlargement of a sagittal section through the joint (arrows indicate movement in each part of the joint cavity)

Copyright © 2011 Pearson Education, Inc. Figure 9.10c

The Temporomandibular Joint


Selected Synovial Joints •  Shoulder (glenohumeral) joint

•  The most freely movable joint lacks stability •  Articular capsule is thin and loose •  Muscle tendons contribute to joint stability

•  The rotator cuff is made up of four muscles and their associated tendons (“SITS”) •  Subscapularis •  Infraspinatus •  Teres minor •  Supraspinatus

•  Rotator cuff injuries are common shoulder injuries


Glenohumeral Joint

Figure 9.11a, b

Acromion of scapula

Synovial membrane Fibrous capsule

Hyaline cartilage

Coracoacromial ligament

Subacromial bursa

Fibrous articular capsule

Tendon sheath

Tendon of long head of biceps brachii muscle

(a) Frontal section through right shoulder joint

Synovial cavity of the glenoid cavity containing synovial fluid

Glenoid labrum

Humerus

Fibrous capsule

Hyaline cartilage

Synovial cavity of the glenoid cavity containing synovial fluid

Glenoid labrum

Humerus

(b) Cadaver photo corresponding to (a)


The Shoulder Joint

Figure 9.11c

Acromion Coracoacromial ligament Subacromial bursa Coracohumeral ligament Greater tubercle of humerus Transverse humeral ligament Tendon sheath Tendon of long head of biceps brachii muscle

Articular capsule reinforced by glenohumeral ligaments

Subscapular bursa Tendon of the subscapularis muscle Scapula

Coracoid process

(c) Anterior view of right shoulder joint capsule

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The Shoulder Joint

Figure 9.11d, e

Acromion

Coracoid process Articular capsule Glenoid cavity Glenoid labrum

Tendon of long head of biceps brachii muscle Glenohumeral ligaments Tendon of the subscapularis muscle Scapula

Posterior Anterior (d) Lateral view of socket of right shoulder joint, humerus removed

(e) Posterior view of an opened left shoulder joint

Head of humerus

Muscle of rotator cuff (cut)

Acromion (cut)

Glenoid cavity of scapula

Capsule of shoulder joint (opened)



•  Elbow joint •  Allows flexion and extension •  The humerus’ articulation with the trochlear

notch of the ulna forms the hinge •  Tendons of biceps and triceps brachii provide

stability


Elbow Joint

Figure 9.12a, b

Articular capsule

Synovial membrane

Synovial cavity

Articular cartilage

Coronoid process

Tendon of brachialis muscle

Ulna

Humerus

Fat pad

Tendon of triceps muscle Bursa

Trochlea

Articular cartilage of the trochlear notch (a) Mid-sagittal section through right elbow (lateral view)

Humerus

Lateral epicondyle

Articular capsule Radial collateral ligament

Olecranon process

(b) Lateral view of right elbow joint

Anular ligament

Radius

Ulna


Elbow Joint

Figure 9.12c, d

Articular capsule Anular ligament

Coronoid process

(d) Medial view of right elbow

Radius

Humerus

Medial epicondyle Ulnar collateral ligament

Ulna

Anular ligament

Humerus

Medial epicondyle

Ulnar collateral ligament

Ulna

Articular capsule

Radius

Coronoid process of ulna

(c) Cadaver photo of medial view of right elbow


Wrist Joint •  Stabilized by numerous ligaments •  •  Composed of radiocarpal and intercarpal joint

•  Radiocarpal joint —joint between the radius and proximal carpals (the scaphoid and lunate) •  Allows for flexion, extension, adduction,

abduction, and circumduction •  Intercarpal joint —joint between the proximal and

distal rows or carpals •  Allows for gliding movement


Wrist Joint

Figure 9.13b

Distal radioulnar joint


Articular disc Radial

collateral ligament

Radiocarpal joint

Intercarpal joint

(b) Wrist joints, coronal section

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Wrist Joint

Figure 9.13c

Hamate

Carpo- metacarpal ligaments

Pisiform

Lunate

Radius Ulna


Radial collateral ligament

Palmar radiocarpal ligament

Intercarpal ligaments

Trapezium

Capitate

Scaphoid

(c) Ligaments of the wrist, anterior (palmar) view Copyright © 2011 Pearson Education, Inc.


•  Hip joint •  A ball-and-socket structure •  Movements occur in all axes • Limited by ligaments and acetabulum

•  Head of femur articulates with acetabulum •  Stability comes chiefly from acetabulum and

capsular ligaments •  Muscle tendons contribute somewhat to

stability


Frontal Section and Anterior View of the Hip Joint

Figure 9.14a, b

Articular cartilage Coxal (hip) bone Ligament of the head of the femur (ligamentum teres)

Synovial cavity Articular capsule

Acetabular labrum

Femur

(a) Frontal section through the right hip joint

Acetabular labrum

Synovial membrane

Ligament of the head of the femur (ligamentum teres)

Head of femur

Articular capsule (cut)

(b) Photo of the interior of the hip joint, lateral view


Anterior inferior iliac spine

Iliofemoral ligament

Pubofemoral ligament

Greater trochanter

(d) Anterior view of right hip joint, capsule in place

Posterior View of the Hip Joint

Figure 9.14c, d

Ischium

Iliofemoral ligament

Ischiofemoral ligament

Greater trochanter of femur

(c) Posterior view of right hip joint, capsule in place



•  Knee joint •  The largest and most complex joint •  Primarily acts as a hinge joint •  Has some capacity for rotation when leg is flexed •  Structurally considered compound and bicondyloid •  Two fibrocartilage menisci occur within the joint cavity •  Femoropatellar joint—shares the joint cavity

•  Allows patella to glide across the distal femur


Sagittal Section of Knee Joint

Figure 9.15a (a) Sagittal section through the right knee joint

Femur

Tendon of quadriceps femoris

Suprapatellar bursa

Patella Subcutaneous prepatellar bursa

Synovial cavity Lateral meniscus

Posterior cruciate ligament

Infrapatellar fat pad Deep infrapatellar bursa Patellar ligament

Articular capsule

Lateral meniscus Anterior cruciate ligament

Tibia

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Superior View of Knee Joint

Figure 9.15b

(b) Superior view of the right tibia in the knee joint, showing the menisci and cruciate ligaments

Medial meniscus

Articular cartilage on medial tibial condyle

Anterior

Anterior cruciate ligament

Articular cartilage on lateral tibial condyle

Lateral meniscus



Anterior View of Knee

Figure 9.15c

Quadriceps femoris muscle Tendon of quadriceps femoris muscle

Patella Lateral patellar retinaculum

Medial patellar retinaculum Tibial collateral ligament

Tibia

Fibular collateral ligament

Fibula

(c) Anterior view of right knee

Patellar ligament


Knee Joint

•  Ligaments of the knee joint •  Become taut when knee is extended •  These extracapsular and capsular ligaments

are • Fibular and tibial collateral ligament • Oblique popliteal ligament • Arcuate popliteal ligament


Posterior View of Knee Joint

Figure 9.15d

Articular capsule

Oblique popliteal ligament

Lateral head of gastrocnemius muscle


Arcuate popliteal ligament

Tibia

Femur

Medial head of gastrocnemius muscle

Tendon of semimembranosus muscle

(d) Posterior view of the joint capsule, including ligaments

Popliteus muscle (cut)

Tendon of adductor magnus

Bursa

Tibial collateral ligament


Anterior View of Flexed Knee

Figure 9.15e, f



Medial condyle

Tibial collateral ligament


Medial meniscus

Patellar ligament

Patella

Quadriceps tendon

Lateral condyle of femur

Lateral meniscus

Fibula

(e) Anterior view of flexed knee, showing the cruciate ligaments (articular capsule removed, and quadriceps tendon cut and reflected distally)

Tibia

Medial femoral condyle


Medial meniscus on medial tibial condyle

Patella

(f) Photograph of an opened knee joint; view similar to (e)


Knee Joint •  Intracapsular ligaments

•  Cruciate ligaments—prevent undesirable movements at the knee •  Anterior cruciate ligament—prevents anterior

sliding of the tibia •  Posterior cruciate ligament—prevents forward

sliding of the femur or backward displacement of the tibia

•  Cross each other like an “X” •  Each cruciate ligament runs from the proximal tibia to

the distal femur •  Anterior cruciate ligament •  Posterior cruciate ligament

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Stabilizing function of cruciate ligaments

During movement of the knee the anterior cruciate prevents anterior sliding of the tibia; the posterior cruciate prevents posterior sliding of the tibia.


(a)


Quadriceps muscle Femur Patella

Lateral meniscus

Tibia

Medial condyle

(b)



When the knee is fully extended, both cruciate ligaments are taut and the knee is locked.

1 2

Figure 9.16a, b Copyright © 2011 Pearson Education, Inc.

The “Unhappy Triad”

•  Lateral blows to the knee can tear: •  Tibial collateral ligament and medial meniscus •  Anterior cruciate ligament


Lateral Medial

Patella (outline)

Tibial collateral ligament (torn)

Anterior view

Medial meniscus (torn)

Anterior cruciate ligament (torn)

Lateral force

The “Unhappy Triad”

Figure 9.17 Copyright © 2011 Pearson Education, Inc.

Selected Synovial Joint •  Ankle joint

•  A hinge joint between •  United inferior ends of tibia and fibula •  The talus of the foot

•  Allows the movements •  Dorsiflexion and plantar flexion only

•  Medially and laterally stabilized by ligaments •  Medial (deltoid) ligament •  Lateral ligament

•  Inferior ends of tibia and fibula are joined by ligaments •  Anterior and posterior tibiofibular ligaments


The Ankle Joint

Figure 9.18a

Tibia Calcaneal tendon

Calcaneus Navicular bone

Subtalar joint

(a) Cadaver photo of ankle and foot, sagittal section

Intermediate cuneiform bone Tendon of flexor

digitorum longus

Metatarsal bone (II)

Interphalangeal joint

Metatarsophalangeal joint

Cuneonavicular joint Talonavicular joint

Talocalcaneal ligament

Tibialis posterior muscle

Ankle (talocrural) joint

Tarsometatarsal joint

Talus


Ligaments of the Ankle Joint

Figure 9.18b

Medial malleolus

Calcaneus

Sustentaculum tali

Medial (deltoid) ligament

Talus

Navicular

Tibia

1st metatarsal

(b) Right ankle, medial view

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Figure 9.18c

Anterior tibiofibular ligament

Anterior talofibular ligament

Calcaneus

Metatarsals

Lateral malleolus

Posterior tibiofibular ligament

Posterior talofibular ligament Calcaneofibular ligament

Tibia

Talus

Cuboid

Fibula

(c) Right ankle, lateral view

Lateral ligament



Figure 9.18d

Talus

Posterior talofibular ligament

Posterior tibiofibular ligament

Interosseous membrane

Calcaneofibular ligament

Fibula Tibia

Medial (deltoid) ligament

Calcaneus

(d) Right ankle, posterior view


Disorders of Joints •  Structure of joints makes them prone to traumatic stress

•  Torn cartilage—common injury to meniscus of knee joint •  Sprains—ligaments of a reinforcing joint are stretched or torn •  Dislocation—occurs when the bones of a joint are forced out of alignment

•  Function of joints makes them subject to friction and wear •  Affected by inflammatory and degenerative processes

•  Bursitis—inflammation of a bursa due to injury or friction •  Tendonitis—inflammation of a tendon sheath •  Arthritis—describes over 100 kinds of joint-damaging diseases

•  Osteoarthritis—most common type of “wear and tear” arthritis •  Rheumatoid arthritis—a chronic inflammatory disorder •  Gouty arthritis (gout)—uric acid build-up causes pain in joints

•  Lyme disease—inflammatory disease often resulting in joint pain

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