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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
Copyright © 2011 Pearson Education, Inc.
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
Copyright © 2011 Pearson Education, Inc.
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
Copyright © 2011 Pearson Education, Inc.
Classifications of Joints
Copyright © 2011 Pearson Education, Inc.
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
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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.
2
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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
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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
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Symphyses
Figure 9.2b
Fibrocartilaginous intervertebral disc
Pubic symphysis
Body of vertebra
Hyaline cartilage
(b) Symphyses
Bones united by fibrocartilage
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Synovial Joints
• Most movable type of joint • All are diarthroses • Each contains a fluid-filled joint cavity
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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
3
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General Structure of Synovial Joints
• 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
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General Structure of Synovial Joints
• 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
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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
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Periosteum
Ligament
Fibrous capsule Synovial membrane
Joint cavity (contains synovial fluid) Articular (hyaline) cartilage
Articular capsule
(a) A typical synovial joint
General Structure of Synovial Joints
Figure 9.3a
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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
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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
4
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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
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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.
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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
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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
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Angular Movements
• Increase or decrease angle between bones • Movements involve • Flexion and extension • Abduction and adduction • Circumduction
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Angular Movements
Figure 9.6b
(b) Angular movements: flexion and extension of the neck
Extension
Flexion
5
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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
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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
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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
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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
6
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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
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Special Movements
• Supination—forearm rotates laterally, palm faces anteriorly
• Pronation—forearm rotates medially, palm faces posteriorly • Brings radius across the ulna
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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)
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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
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Special Movements
• Inversion and eversion • Special movements at the foot • Inversion—turns sole medially • Eversion—turns sole laterally
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Eversion Inversion
(e) Inversion Turning the sole of the foot medially
Eversion Turning the sole of the foot laterally
Special Movements
Figure 9.7e
7
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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
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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
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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
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Plane Joint
Figure 9.8a
(a) Plane joint
Gliding
Metacarpals
Carpals
Nonaxial movement
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Synovial Joints Classified by Shape
• 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
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Hinge Joint
Figure 9.8b
(b) Hinge joint
Medial/ lateral axis
Flexion and extension
Humerus
Ulna
Uniaxial movement
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Synovial Joints Classified by Shape
• Pivot joints • Classified as uniaxial – rotating bone only
turns around its long axis • Examples • Proximal radioulnar joint • Joint between atlas and axis
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Pivot Joint
Figure 9.8c
(c) Pivot joint
Ulna
Vertical axis
Rotation Radius
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Synovial Joints Classified by Shape
• 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
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Condyloid Joint
Figure 9.8d
(d) Condyloid joint
Medial/ lateral axis
Adduction and abduction
Flexion and extension
Metacarpals
Phalanges
Anterior/ posterior axis
Biaxial movement
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Synovial Joints Classified by Shape
• 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
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Synovial Joints Classified by Shape
Figure 9.8e
(e) Saddle joint
Anterior/ posterior axis
Medial/ lateral axis
Adduction and abduction
Metacarpal 1
Trapezium Flexion and extension
9
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Synovial Joints Classified by Shape
• 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
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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
Flexion and extension
Scapula
Humerus
Multiaxial movement
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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
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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
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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
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Selected Synovial Joints
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
10
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Selected Synovial Joints
• 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
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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
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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)
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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
11
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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)
Copyright © 2011 Pearson Education, Inc.
Selected Synovial Joints
• 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
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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
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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
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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
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Wrist Joint
Figure 9.13b
Distal radioulnar joint
Ulnar collateral ligament
Articular disc Radial
collateral ligament
Radiocarpal joint
Intercarpal joint
(b) Wrist joints, coronal section
12
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Wrist Joint
Figure 9.13c
Hamate
Carpo- metacarpal ligaments
Pisiform
Lunate
Radius Ulna
Ulnar collateral ligament
Radial collateral ligament
Palmar radiocarpal ligament
Intercarpal ligaments
Trapezium
Capitate
Scaphoid
(c) Ligaments of the wrist, anterior (palmar) view Copyright © 2011 Pearson Education, Inc.
Selected Synovial Joints
• 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
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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
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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
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Selected Synovial Joints
• 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
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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
13
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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
Posterior cruciate ligament
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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
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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
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Posterior View of Knee Joint
Figure 9.15d
Articular capsule
Oblique popliteal ligament
Lateral head of gastrocnemius muscle
Fibular collateral ligament
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
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Anterior View of Flexed Knee
Figure 9.15e, f
Fibular collateral ligament
Posterior cruciate ligament
Medial condyle
Tibial collateral ligament
Anterior cruciate 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
Anterior cruciate ligament
Medial meniscus on medial tibial condyle
Patella
(f) Photograph of an opened knee joint; view similar to (e)
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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.
Anterior cruciate ligament
(a)
Posterior cruciate ligament
Quadriceps muscle Femur Patella
Lateral meniscus
Tibia
Medial condyle
(b)
Anterior cruciate ligament
Posterior cruciate ligament
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
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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
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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
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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
15
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Ligaments of the Ankle Joint
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
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Ligaments of the Ankle Joint
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
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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