Joints Or articulations Sites where two bones meet 2
fundamental functions 1. Motility 2. Hold skeleton together -
Weakest part of skeleton
Slide 3
Classification of Joints Classified by structure and function
Structural material binding Fibrous Cartilaginous Synovial joints
Function Amount of movement Synarthroses immovable Amphiarthroses
slightly movable Diarthroses freely movable General fibrous =
immobile Synovial freely movable Cartilaginous - both
Slide 4
Fibrous Joints Bones joined by fibrous tissue Dense fibrous
connective tissue No joint cavity present Most are immovable 3
types 1.Sutures 2.Syndesmoses 3.gomphoses
Slide 5
Fibrous Joints 1. Sutures seams Only between bones of skull
Rigid slices knit bone together During middle age ossifies closed
sutures synostoses Immobile = protection
Slide 6
Figure 8.1a Dense fibrous connective tissue Suture line (a)
Suture Joint held together with very short, interconnecting fibers,
and bone edges interlock. Found only in the skull.
Slide 7
Fibrous Joints 2. Syndesmoses Bones connected by ligaments Only
cords or bands of fibrous tissue Amount of movement depends on
length of connecting fibers
Slide 8
Figure 8.1b Fibula Tibia Ligament (b) Syndesmosis Joint held
together by a ligament. Fibrous tissue can vary in length, but is
longer than in sutures.
Slide 9
Fibrous Joints 3. Gomphoses Peg in socket fibrous joint Tooth
joint Teeth embedded in sockets periodontal ligament
Slide 10
Figure 8.1c Root of tooth Socket of alveolar process
Periodontal ligament (c) Gomphosis Peg in socket fibrous joint.
Periodontal ligament holds tooth in socket.
Slide 11
Cartilaginous Joints Unit articulating bones Lack joint cavity
Not highly mobile 2 types 1.Synchondroses 2.Symphyses
Slide 12
Cartilaginous Joints 1. Synchondroses Bones united by bar or
plate of hyaline cartilage Epiphyseal plates in long bones of
children Costal cartilage of first rib
Slide 13
Figure 8.1c Root of tooth Socket of alveolar process
Periodontal ligament (c) Gomphosis Peg in socket fibrous joint.
Periodontal ligament holds tooth in socket.
Slide 14
Cartilaginous Joints 2. Symphyses growing together Intervening
pad or plate of fibrocartilage Compress able and resilience
Amphiarthrotic joints Designed for strength and flexibility
Slide 15
Figure 8.2b Fibrocartilaginous intervertebral disc Pubic
symphysis Body of vertebra Hyaline cartilage (b) Symphyses Bones
united by fibrocartilage
Slide 16
Synovial Joints joint eggs Articulating bones are separated by
a fluid filled joint cavity Freedom of movement Freely moveable
diarthroses
Slide 17
Synovial Joints General Structure 6 distinguishing
characteristics: 1. Articular Cartilage glassy smooth hyaline
articular cartilage Thin, spongy cushions absorb compression 2.
Joint (Synovial) Cavity joint cavity potential space with a small
amount of synovial fluid 3. Articular Capsule 2 layered articular
capsule or joint capsule Inner synovial membrane loose CT 4.
Synovial Fluid occupies all free space Derived by filtration
Viscous, egg white consistency Slippery weight bearing film reduces
friction
Slide 18
Synovial Joints General Structure 5. Reinforcing Ligaments band
like ligaments Usually capsular or intrinsic ligaments thickened
parts of fibrous capsule Outside capsule distinct extra- capsular
ligaments Deep to it intracapsular ligaments 6. Nerves and blood
vessels richly supplied with sensory nerve fibers Some detect pain
Most monitor joint positions and stretch Richly supplied with
capillary beds produce filtrate
Slide 19
Synovial Joints General Structure Other Components Cushioning
fatty pads Articular discs menisci wedges of fibrocartilage
Brusae And Tendon Sheaths Associated with joints Bags of
lubricants Ball bearings reduce friction Bursae flattened fibrous
sacs Thin film of synovial fluid Occur where ligaments, muscles,
skin, tendons, or bones rub together Tendon Sheath Elongated bursae
wraps completely around tendon subjected to friction Where several
tendons crowded together
Slide 22
Figure 8.4b Coracoacromial ligament Subacromial bursa Cavity in
bursa containing synovial fluid Bursa rolls and lessens friction.
Humerus head rolls medially as arm abducts. (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
Slide 23
Stability of Synovial Joints Stabilized so do not dislocate
Stability depends on 1.Shape of articular surfaces 2.Number and
position of ligaments 3.Muscle tone
Slide 24
Stability of Synovial Joints 1. Articular Surfaces Shapes
determine movements possible Minor role in stability Many joints
shallow sockets non- complementary articulating surfaces When large
socket deep stability vastly improved
Slide 25
Stability of Synovial Joints 2. Ligaments more ligaments
stronger Brace joints 3. Muscle Tone muscle tendons cross joints
Tendons taught at all times Muscle tone low levels of contractile
activity in relaxed muscles keep them muscles healthy and ready to
react
Slide 26
Movements Allowed by Synovial Joints Muscle origin attached to
immobile or less movable bone Insertion attached to movable bone
Muscle contract insertion moves towards origin Nonaxial movement
slipping movements only no axis Uniaxial movements movement in 1
plane Biaxial movement movement in 2 planes Multiaxial movement
movement in or around all 3 planes and axes
Slide 27
3 General Types of Movement 1.Gliding 2.Angular Movements
3.Rotations
Slide 28
1. Gliding Simplest One flat bone surface slides over another
Back and forth, side to side No angulations or rotation Intercarpal
and intercostal joints
Slide 29
Figure 8.5a Gliding (a) Gliding movements at the wrist
Slide 30
2. Angular Increase or decrease angle between 2 bones Any plane
of the body Include flexion, extension, hyperextension, abduction,
adduction and circumduction
Slide 31
Figure 8.5b (b) Angular movements: flexion, extension, and
hyperextension of the neck HyperextensionExtension Flexion
Slide 32
2. Angular A. Flexion Bending movement Usually along sagittal
plane Decrease angle of joint Head toward chest
Slide 33
Figure 8.5c Hyperextension Flexion Extension (c) Angular
movements: flexion, extension, and hyperextension of the vertebral
column
Slide 34
2. Angular B. Extension Reverse of flexion Occurs at same
joints Movement along sagittal plane Increase the angle Straightens
a flexed limb or body part Ex. Straightening the knee
Hyperextension extension beyond anatomical position
Slide 35
Figure 8.5c Hyperextension Flexion Extension (c) Angular
movements: flexion, extension, and hyperextension of the vertebral
column
Slide 36
2. Angular C. Abduction moving away Movement of a limb away
from the midline Along frontal plane
Slide 37
Figure 8.5e Abduction Adduction (e) Angular movements:
abduction, adduction, and circumduction of the upper limb at the
shoulder Circumduction
Slide 38
2. Angular D. Adduction moving toward Opposite abduction
Movement of a limb toward body midline
Slide 39
Figure 8.5e Abduction Adduction (e) Angular movements:
abduction, adduction, and circumduction of the upper limb at the
shoulder Circumduction
Slide 40
2. Angular E. Circumduction Moving limb so it describes a cone
in space Distal end of limb moves in a circle
Slide 41
3. Rotation Turning of bone around its long axis 1 st 2
cervical vertebrae Hip, shoulder Towards or away from midline
Slide 42
Figure 8.5f Lateral rotation Medial rotation Rotation (f)
Rotation of the head, neck, and lower limb
Slide 43
Special Movements Do not fit into any of other categories
Supination turning backwards radius around ulna Pronation turning
forward radius around ulna
Slide 44
Figure 8.6a Supination (radius and ulna are parallel) (a)
Pronation (P) and supination (S) Pronation (radius rotates over
ulna)
Slide 45
Special Movements Dorsiflexion increase and decrease movement
of foot, foot superior approaches shin Plantar Flexion pointing
toes
Special Movements Inversion sole of foot turns medially
Eversion sole face laterally
Slide 48
Figure 8.6c Eversion Inversion (c) Inversion and eversion
Slide 49
Special Movements Protraction anterior movement in transverse
plane Retraction posterior movement in a transverse plane
Slide 50
Figure 8.6d Protraction of mandible Retraction of mandible (d)
Protraction and retraction
Slide 51
Special Movements Elevation lift body part superiorly
Depression moving elevated part inferiorly
Slide 52
Figure 8.6e Elevation of mandible Depression of mandible (e)
Elevation and depression
Slide 53
Special Movements Opposition joint between metacarpal 1 and
trapezium Movement of thumb
Slide 54
Figure 8.6f (f) Opposition Opposition
Slide 55
Types of Synovial Joints 6 categories 1. Plane Joint Flat Allow
only short non-axial gliding movement No rotation Non-axial plane
joints
Slide 56
Figure 8.7a a b c d e f Nonaxial Uniaxial Biaxial Multiaxial a
Plane joint (intercarpal joint)
Slide 57
Types of Synovial Joints 2. Hinge Joints Cylindrical end of
bone conforms to trough shaped surface Motion single plane
Resembles mechanical hinge Permit flexion and extension only
Slide 58
Figure 8.7b b Hinge joint (elbow joint) a b c d e f Nonaxial
Uniaxial Biaxial Multiaxial
Slide 59
Types of Synovial Joints 3. Pivot Joints Rounded end of bone
conforms to sleeve or ring composed of bone Uniaxial rotation Atlas
and dens joint Ex. Head side to side
Slide 60
Figure 8.7c c Pivot joint (proximal radioulnar joint) a b c d e
f Nonaxial Uniaxial Biaxial Multiaxial
Slide 61
Types of Synovial Joints 4. Condyloid Joint Also ellipsoidal
joint Fits into complete depressions in another articulating
surfaces oval Angular motion Ex. Radiocarpal joints
Slide 62
Figure 8.7d d Condyloid joint (metacarpophalangeal joint) a b c
d e f Nonaxial Uniaxial Biaxial Multiaxial
Slide 63
Types of Synovial Joints 5. Saddle Joints Like condyloid joint
but allow greater motion Both concave and convex areas Shaped like
a saddle Carpometacarpal joint of thumb
Slide 64
Figure 8.7e e Saddle joint (carpometacarpal joint of thumb) a b
c d e f Nonaxial Uniaxial Biaxial Multiaxial
Slide 65
Types of Synovial Joints 6. Ball and Sockets Spherical or
hemispherical head of one bone articulates with cup like socket of
another Multiaxial and most freely moving synovial Universal
movement shoulder and hip
Slide 66
Figure 8.7f f Ball-and-socket joint (shoulder joint) a b c d e
f Nonaxial Uniaxial Biaxial Multiaxial
Slide 67
Synovial Joints- Knee Joint Largest, most complex joint of body
Three joints surrounded by a single joint cavity: Femoropatellar
joint: Plane joint Allows gliding motion during knee flexion
Lateral and medial tibiofemoral joints between the femoral condyles
and the C-shaped lateral and medial menisci (semilunar cartilages)
of the tibia Allow flexion, extension, and some rotation when knee
is partly flexed
Slide 68
Figure 8.8a (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
Slide 69
Figure 8.8b (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 cruciate
ligament Articular cartilage on lateral tibial condyle Lateral
meniscus Posterior cruciate ligament
Slide 70
Synovial Joints- Knee Joint At least 12 associated bursae
Capsule is reinforced by muscle tendons: E.g., quadriceps and
semimembranosus tendons Joint capsule is thin and absent anteriorly
Anteriorly, the quadriceps tendon gives rise to: Lateral and medial
patellar retinacula Patellar ligament
Synovial Joints- Knee Joint Capsular and extracapsular
ligaments Help prevent hyperextension Intracapsular ligaments:
Anterior and posterior cruciate ligaments Prevent
anterior-posterior displacement Reside outside the synovial
cavity
Slide 73
Figure 8.8d 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
Slide 74
Synovial Joint Shoulder Joint Ball-and-socket joint: head of
humerus and glenoid fossa of the scapula Stability is sacrificed
for greater freedom of movement
Slide 75
Figure 8.10a PLAY Animation: Rotatable shoulder 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 Synovial
cavity of the glenoid cavity containing synovial fluid Humerus (a)
Frontal section through right shoulder joint
Slide 76
Synovial Joint Shoulder Joint Reinforcing ligaments:
Coracohumeral ligamenthelps support the weight of the upper limb
Three glenohumeral ligamentssomewhat weak anterior
reinforcements
Slide 77
Synovial Joint Shoulder Joint Reinforcing muscle tendons:
Tendon of the long head of biceps: Travels through the
intertubercular groove Secures the humerus to the glenoid cavity
Four rotator cuff tendons encircle the shoulder joint:
Subscapularis Supraspinatus Infraspinatus Teres minor
Slide 78
Figure 8.10c 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
Slide 79
Figure 8.10d 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 PosteriorAnterior (d) Lateral view of socket of right
shoulder joint, humerus removed
Slide 80
Synovial Joint Elbow Joint Radius and ulna articulate with the
humerus Hinge joint formed mainly by trochlear notch of ulna and
trochlea of humerus Flexion and extension only
Slide 81
Figure 8.11a 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) Median sagittal
section through right elbow (lateral view)
Slide 82
Synovial Joint Elbow Joint Anular ligamentsurrounds head of
radius Two capsular ligaments restrict side-to-side movement: Ulnar
collateral ligament Radial collateral ligament
Slide 83
Figure 8.11b Humerus Lateral epicondyle Articular capsule
Radial collateral ligament Olecranon process Anular ligament Radius
Ulna (b) Lateral view of right elbow joint
Slide 84
PLAY Animation: Rotatable elbow Figure 8.11d Articular capsule
Anular ligament Coronoid process (d) Medial view of right elbow
Radius Humerus Medial epicondyle Ulnar collateral ligament
Ulna
Slide 85
Synovial Joint - Hip (Coxal) Joint Ball-and-socket joint Head
of the femur articulates with the acetabulum Good range of motion,
but limited by the deep socket Acetabular labrumenhances depth of
socket
Slide 86
Figure 8.12a 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 Reinforcing ligaments: Iliofemoral ligament
Pubofemoral ligament Ischiofemoral ligament Ligamentum teres
PLAY Animation: Rotatable hip Figure 8.12c Ischium Iliofemoral
ligament Ischiofemoral ligament Greater trochanter of femur (c)
Posterior view of right hip joint, capsule in place
Slide 89
Figure 8.12d Anterior inferior iliac spine Iliofemoral ligament
Pubofemoral ligament Greater trochanter (d) Anterior view of right
hip joint, capsule in place
Slide 90
Temporomandibular Joint (TMJ) Mandibular condyle articulates
with the temporal bone Two types of movement Hingedepression and
elevation of mandible Glidinge.g. side-to-side (lateral excursion)
grinding of teeth Most easily dislocated joint in the body
Slide 91
Figure 8.13a Zygomatic process Mandibular fossa Articular
tubercle Infratemporal fossa External acoustic meatus Articular
capsule Ramus of mandible Lateral ligament (a) Location of the
joint in the skull
Slide 92
Figure 8.13b 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
Slide 93
Figure 8.13c Lateral excursion: lateral (side-to-side)
movements of the mandible Outline of the mandibular fossa Superior
view
Slide 94
Common Joint Injuries Sprains The ligaments are stretched or
torn Partial tears slowly repair themselves Complete ruptures
require prompt surgical repair Cartilage tears Due to compression
and shear stress Fragments may cause joint to lock or bind
Cartilage rarely repairs itself Repaired with arthroscopic
surgery
Slide 95
Figure 8.14 Torn meniscus
Slide 96
Common Joint Injuries Dislocations (luxations) Occur when bones
are forced out of alignment Accompanied by sprains, inflammation,
and joint immobilization Caused by serious falls or playing sports
Subluxationpartial dislocation of a joint
Slide 97
Homeostatic Imbalances Bursitis An inflammation of a bursa,
usually caused by a blow or friction Treated with rest and ice and,
if severe, anti- inflammatory drugs Tendonitis Inflammation of
tendon sheaths typically caused by overuse Symptoms and treatment
similar to bursitis
Slide 98
Homeostatic Imbalances Arthritis >100 different types of
inflammatory or degenerative diseases that damage joints Most
widespread crippling disease in the U.S. Symptoms; pain, stiffness,
and swelling of a joint Acute forms: caused by bacteria, treated
with antibiotics Chronic forms: osteoarthritis, rheumatoid
arthritis, and gouty arthritis
Slide 99
Homeostatic Imbalances Osteoarthritis (OA) Common,
irreversible, degenerative (wear-and-tear) arthritis 85% of all
Americans develop OA, more women than men Probably related to the
normal aging process More cartilage is destroyed than replaced in
badly aligned or overworked joints Exposed bone ends thicken,
enlarge, form bone spurs, and restrict movement Treatment: moderate
activity, mild pain relievers, capsaicin creams, glucosamine and
chondroitin sulfate
Slide 100
Homeostatic Imbalances Rheumatoid Arthritis (RA) Chronic,
inflammatory, autoimmune disease of unknown cause Usually arises
between age 40 and 50, but may occur at any age; affects 3 times as
many women as men Signs and symptoms include joint pain and
swelling (usually bilateral), anemia, osteoporosis, muscle
weakness, and cardiovascular problems
Slide 101
Homeostatic Imbalances Rheumatoid Arthritis (RA) cont RA begins
with synovitis of the affected joint Inflammatory blood cells
migrate to the joint, release inflammatory chemicals Inflamed
synovial membrane thickens into a pannus Pannus erodes cartilage,
scar tissue forms, articulating bone ends connect (ankylosis)
Slide 102
Figure 8.15
Slide 103
Homeostatic Imbalances Rheumatoid Arthritis (RA) Treatment -
Conservative therapy: aspirin, long-term use of antibiotics, and
physical therapy Progressive treatment: anti-inflammatory drugs or
immunosuppressants New biological response modifier drugs
neutralize inflammatory chemicals
Slide 104
Homeostatic Imbalances Gouty Arthritis Deposition of uric acid
crystals in joints and soft tissues, followed by inflammation More
common in men Typically affects the joint at the base of the great
toe In untreated gouty arthritis, the bone ends fuse and immobilize
the joint Treatment: drugs, plenty of water, avoidance of
alcohol
Slide 105
Homeostatic Imbalances Lyme Disease Caused by bacteria
transmitted by the bites of ticks Symptoms: skin rash, flu-like
symptoms, and foggy thinking May lead to joint pain and arthritis
Treatment: antibiotics
Slide 106
Developmental Aspects By embryonic week 8, synovial joints
resemble adult joints A joints size, shape, and flexibility are
modified by use Advancing years take their toll on joints:
Ligaments and tendons shorten and weaken Intervertebral discs
become more likely to herniate Most people in their 70s have some
degree of OA Exercise that coaxes joints through their full range
of motion is key to postponing joint problems