Transcript Synovial Joints

Human Anatomy & Physiology
FIFTH EDITION
Elaine N. Marieb
Chapter 8
Joints
Part A
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Joints (Articulations)
• Weakest parts of the skeleton
• Articulation – site where two or more bones meet
• Functions
• Give the skeleton mobility
• Hold the skeleton together
2
Classification of Joints: Structural
• Structural classification focuses on the material
binding bones together and whether or not a joint
cavity is present
• The three structural classifications are:
• Fibrous
• Cartilaginous
• Synovial
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Classification of Joints: Functional
• Functional classification is based on the amount of
movement allowed by the joint
• The three functional class of joints are:
• Synarthroses – immovable
• Amphiarthroses – slightly movable
• Diarthroses – freely movable
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Table
A Structural Classification of Articulations
Structure
Bony fusion
Fibrous joint
Type
Functional
Category
Example
Synostosis
Synarthrosis
Frontal, Coxa
Suture
Synarthrosis
Temporofrontal
Gomphosis
Synarthrosis
Teeth
Syndesmosis
Amphiarthrosis
Synchondrosis
Synarthrosis
Symphysis
Amphiarthrosis
Tibia-fibula
True ribs-sternum
Cartilaginous joint
Monaxial
Synovial joint
Biaxial
Triaxial
Pubis
Hinge, pivot,
Diarthroses
ellipsoidal, saddle
ball & socket
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Fibrous Structural Joints
• The bones are jointed by fibrous tissues
• There is no joint cavity
• Most are immovable
• There are three
types – sutures,
syndesmoses,
and gomphoses
Figure 8.1a
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Fibrous Joints
Figure 8.3
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Fibrous Structural Joints: Sutures
• Occur between the bones of the skull
• Comprised of interlocking junctions completely filled
with dense irregular CT fibers
• Bind bones tightly together, but allow for growth
during youth
• In middle age, skull bones fuse and are called
synostoses
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Fibrous Structural Joints: Syndesmoses
• Bones are connected by a fibrous tissue ligament
• Movement varies from immovable to slightly variable
• Examples include the connection between the tibia and
fibula, and the radius and ulna
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Fibrous Structural Joints
Figure 8.1b
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Fibrous Structural Joints: Gomphoses
gomph- = wedge-shaped bolt
• The peg-in-socket fibrous joint between a tooth and its
alveolar socket
• The fibrous connection is the periodontal ligament
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Fibrous Joints
• Gomphosis
• teeth anchored to the
jaw with a periodontal
ligament
• Cone shaped socket
• synarthrotic joint
• The peg-in-socket fibrous
joint between a tooth and
its alveolar socket
• The fibrous connection is
the periodontal ligament
Figure 8.4
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Cartilaginous Joints
• Articulating
bones are
united by
cartilage
• Lack a joint
cavity
• Two types –
synchondroses
and symphyses
Figure 8.2a
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Cartilaginous Joints
Figure 8.2b
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Cartilaginous Joints
Figure 8.2c
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Cartilaginous Joints: Synchondroses
• A bar or plate of hyaline cartilage unites the bones
• All synchondroses are synarthrotic
• Examples include:
• Epiphyseal plates of children
• Joint between the costal cartilage of the first rib and
the sternum
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Cartilaginous Joints: Symphyses
• Hyaline cartilage covers the articulating surface of the
bone and is fused to an intervening pad of
fibrocartilage
• Amphiarthrotic joints designed for strength and
flexibility
• Examples include intervertebral joints and the pubic
symphysis of the pelvis
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Synovial Joints
• Those joints in which the articulating bones are separated
by a fluid-containing joint cavity
• All are freely movable diarthroses
• Examples – all limb joints, and most joints of the body
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Synovial Joints:
General Structure
• Synovial joints all
have the following:
• Articular cartilage
• Joint (synovial)
cavity
• Articular capsule
• Synovial fluid
• Reinforcing
ligaments
Figure 8.3a
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Human Anatomy & Physiology
FIFTH EDITION
Elaine N. Marieb
Illust - Knee Joint
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
23
Synovial Joints: Friction-Reducing Structures
• Bursae – flattened, fibrous sacs lined with synovial
membranes and containing synovial fluid
• Common where ligaments, muscles, skin, tendons, or
bones rub together
• Tendon sheath – elongated bursa that wraps
completely around a tendon
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Synovial Joints: Friction-Reducing Structures
Figure 8.4a, b
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Synovial Joints: Stability
• Stability is determined by:
• Articular surfaces – shape determines what
movements are possible
• Ligaments – unite bones and prevent excessive or
undesirable motion
• Muscles
• Muscle tendons across joints are the most important
stabilizing factor
• Tendons are kept tight at all times by muscle tone
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Synovial Joints: Movement
• Muscle attachment across a joint
• Origin – attachment to the immovable bone
• Insertion – attachment to the movable bone
• Described as movement along transverse, frontal, or
sagittal planes
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Synovial Joints: Range of Motion
• Nonaxial – slipping movements only
• Uniaxial – movement in one plane
• Biaxial – movement in two planes
• Multiaxial – movement in or around all three planes
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Gliding Movements
• One flat bone surface glides or slips over another similar
surface
• Examples – intercarpal and intertarsal joints, and between
the flat articular processes of the vertebrae
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Human Anatomy & Physiology
FIFTH EDITION
Elaine N. Marieb
Chapter 8
Movements
Part B
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Angular Movement
• Flexion
• Extension
• Dorsiflexion and
plantar flexion of
the foot
• Abduction
• Adduction
• Circumduction
Figure 8.5a31
Angular Movement
Figure 8.5b
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Angular Movement
Figure 8.5c, d33
Angular Movement
Figure 8.5e,34
f
Rotation
• The turning of a bone
around its own long
axis
• Examples:
• Between first two
vertebrae (C1 & C2)
• Hip and shoulder
joints
Figure 8.5g
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Special Movements
• Supination
and pronation
• Inversion and
eversion
• Protraction
and retraction
• Elevation and
depression
• Opposition
Figure 8.6a
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Special Movements
Figure 8.6b
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Special Movements
Figure 8.6c
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Special Movements
Figure 8.6d
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Special Movements
Figure 8.6e
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Human Anatomy & Physiology
FIFTH EDITION
Elaine N. Marieb
Chapter 8
Types of Synovial Joints
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
42
Types of Synovial Joints
• Plane joints
• Articular surfaces
are essentially
flat
• Allow only
slipping or
gliding
movements
• Only examples of
nonaxial joints
Figure 8.7a
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Types of Synovial
Joints
• Hinge joints
• Cylindrical projections
of one bone fits into a
trough-shaped surface
on another
• Motion is along a
single plane
• Uniaxial joints permit
flexion and extension
only
• Examples: elbow and
interphalangeal joints
Figure 8.7b
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Pivot Joints
• Rounded end of one
bone protrudes into a
“sleeve,” or ring,
composed of bone (and
possibly ligaments) of
another
• Only uniaxial movement
allowed
• Examples: joint between
the axis and the dens,
and the proximal
radioulnar joint
Figure 8.7c
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Condyloid, or Ellipsoidal, Joints
• Oval articular surface
of one bone fits into a
complementary
depression in another
• Both articular surfaces
are oval
• Biaxial joints permit
all angular motions
• Examples: radiocarpal
(wrist) joints, and
metacarpophalangeal
(knuckle) joints
Figure 8.7d
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Saddle Joints
• Similar to
condyloid joints but
with greater
movement
• Each articular
surface has both a
concave and a
convex surface
• Example:
carpometacarpal
joint of the thumb
Figure 8.7e
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Ball-and-Socket Joints
• A spherical or
hemispherical head
of one bone
articulates with a
cuplike socket of
another
• Multiaxial joints
permit the most
freely moving
synovial joints
• Examples:
shoulder and hip
joints
Figure 8.7f
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Synovial Joints: Shoulder (Glenohumeral)
• Ball-and-socket joint in which stability is sacrificed to
obtain greater freedom of movement
• Head of humerus articulates with the glenoid fossa of the
scapula
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Synovial Joints: Shoulder Stability
• Weak stability is maintained by:
• Thin, loose joint capsule
• Four ligaments – coracohumeral, and three
glenohumeral
• Tendon of the long head of biceps, which travels
through the intertubercular groove and secures the
humerus to the glenoid cavity
• Rotator cuff (four tendons) encircles the shoulder
joint and blends with the articular capsule
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Synovial Joints: Shoulder Stability
Figure 8.8a
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Synovial Joints: Shoulder Stability
Figure 8.8b
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Synovial Joints: Hip 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 and
strong ligaments
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Synovial Joints: Hip Stability
• Acetabular
labrum
• Iliofemoral
ligament
• Pubofemoral
ligament
• Ischiofemoral
ligament
• Ligamentum
teres
Figure 8.9a
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Synovial Joints: Hip Stability
Figure 8.9c, d
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Synovial Joints: Elbow
• Hinge joint that
allows flexion and
extension only
• Radius and ulna
articulate with the
humerus
Stability:
• Annular ligament
• Ulnar collateral
ligament
• Radial collateral
ligament
Figure 8.10a
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Synovial Joints: Elbow Stability
Figure 8.10b, d
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Synovial Joints: Knee
• Largest and most complex joint of the body
• Allow flexion, extension, and some rotation
• Three joints in one surrounded by a single joint cavity
• Femoropatellar
• Lateral and medial tibiofemoral joints
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Synovial Joints: Major Ligaments and Tendons –
Anterior View
• Tendon of the
quadriceps femoris
muscle
• Lateral and medial
patellar retinacula
• Fibular collateral
ligament
• Tibial collateral
ligament
• Patellar ligament
Figure 8.11c
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Synovial Joints: Knee –
Other Supporting Structures
• Anterior cruciate
ligament
• Posterior cruciate
ligament
• Medial meniscus
(semilunar cartilage)
• Lateral meniscus
Figure 8.11b
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Synovial Joints: Knee – Posterior Superficial View
• Adductor magnus
tendon
• Articular capsule
• Oblique popliteal
ligament
• Arcuate popliteal
ligament
• Semimembranosus
tendon
Figure 8.11e
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Human Anatomy & Physiology
FIFTH EDITION
Elaine N. Marieb
Chapter 8
Pathology
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Sprains
• The ligaments reinforcing a joint are stretched or torn
• Partially torn ligaments slowly repair themselves
• Completely torn ligaments require prompt surgical repair
Cartilage Injuries
• The snap and pop of overstressed cartilage
• Common aerobics injury
• Repaired with arthroscopic surgery
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Dislocations
• Occur when bones are forced out of alignment
• Usually accompanied by sprains, inflammation, and
joint immobilization
• Caused by serious falls and are common sports
injuries
• Subluxation – partial dislocation of a joint
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Inflammatory and Degenerative Conditions
• Bursitis
• An inflammation of a bursa, usually caused by a
blow or friction
• Symptoms are pain and swelling
• Treated with anti-inflammatory drugs; excessive
fluid may be aspirated
• Tendonitis
• Inflammation of tendon sheaths typically caused by
overuse
• Symptoms and treatment are similar to bursitis
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Disc Herniation
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Arthritis
• More than 100 different types of inflammatory or
degenerative diseases that damage the joints
• Most widespread crippling disease in the U.S.
• Symptoms – pain, stiffness, and swelling of a joint
• Acute forms are caused by bacteria and are treated
with antibiotics
• Chronic forms include osteoarthritis, rheumatoid
arthritis, and gouty arthritis
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Osteoarthritis (OA)
• Most common chronic arthritis; often called “wearand-tear” arthritis
• Affects women more than men
• 85% of all Americans develop OA
• More prevalent in the aged, and is probably related to
the normal aging process
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Osteoarthritis: Course
• OA reflects the years of abrasion and compression
causing increased production of metalloproteinase
enzymes that break down cartilage
• As one ages, cartilage is destroyed more quickly than
it is replaced
• The exposed bone ends thicken, enlarge, form bone
spurs, and restrict movement
• Joints most affected are the cervical and lumbar spine,
fingers, knuckles, knees, and hips
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Osteoarthritis: Treatments
• OA is slow and irreversible
• Treatments include:
• Mild pain relievers, along with moderate activity
• Magnetic therapy
• Glucosamine sulfate decreases pain and
inflammation
• SAM-e (s-adenosylmethionine) builds up cartilage
matrix and regenerates tissue
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Rheumatoid Arthritis (RA)
• Chronic, inflammatory, autoimmune disease of
unknown cause, with an insidious onset
• Usually arises between the ages of 40 to 50, but may
occur at any age
• Signs and symptoms include joint tenderness, anemia,
osteoporosis, muscle atrophy, and cardiovascular
problems
• The course of RA is marked with exacerbations and
remissions
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Rheumatoid Arthritis: Course
• RA begins with synovitis of the affected joint
• Inflammatory blood cells migrate to the joint, causing
swelling
• Inflamed synovial membrane thickens into a pannus
• Pannus erodes cartilage, scar tissue forms, articulating
bone ends connect
• The end result, ankylosis, produces bent, deformed
fingers
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Rheumatoid Arthritis: Treatment
• Conservative therapy – aspirin, long-term use of
antibiotics, and physical therapy
• Progressive treatment – anti-inflammatory drugs or
immunosuppressants
• The drug Embrel, a biological response modifier,
removes cells that promote inflammation
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Gouty Arthritis
• Deposition of uric acid crystals in joints and soft
tissues, followed by an inflammation response
• Typically, gouty arthritis affects the joint at the base
of the great toe
• In untreated gouty arthritis, the bone ends fuse and
immobilize the joint
• Treatment – colchicine, nonsteroidal antiinflammatory drugs, and glucocorticoids
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Developmental Aspects of Joints
• By embryonic week 8, synovial joints resemble adult
joints
• Few problems occur until late middle age
• Advancing years take their toll on joints including:
• Ligaments and tendons shorten and weaken
• Intervertebral discs become more likely to herniate
• OA is inevitable, and all people of 70 have some
degree of OA
• Prudent exercise (especially swimming) that coaxes
joints through their full range of motion is key to
postponing joint problems
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Rheumatoid arthritis
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1.
2.
3.
4.
5.
6.
7.
o
f
a
t
l
a
s
5.P
o
s
t
e
r
Dens
i
Foramen transversarium
or transverse foramen
Spinous process or ospine
r
Anterior arch of atlas
a
Posterior arch of atlas
Transverse process r
c of skull
Articular facet for base
95
Human Anatomy & Physiology
FIFTH EDITION
Elaine N. Marieb
Pathologies
Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings
Osteoarthritis
• Progressive, degenerative
• 85% of adults
• “wear & tear” caused by
deterioration of articular surfaces
due to constant use
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Osteoarthritis
• Can be painful, debilitating
• Treated w/ NSAIDs,
corticosteroids,
glucosamine/chondroitin
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Rheumatoid Arthritis
• Autoimmune disorder
• Inflammation of synovial membrane causing erosion of
articular surfaces and bone.
• Scar tissue ossifies and fuses bones
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Gout (gouty arthritis)
• Inflammation of synovial joint due to the deposition of
uric acid crystals.
• Usually affects the metatarso-phalangeal joint of the
hallux of males.
100
Gout (gouty arthritis)
• Can cause articular surface to erode and the bone ends to
fuse if untreated.
• Drugs, NSAIDs, & diet modification can lessen severity
or prevent attacks.
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Tendonitis
• Inflammation of tendon sheath due to repetitive use (RSI)
• “Tennis elbow”, “GameBoy Thumb”, Carpal Tunnel
Syndrome
102
Bursitis
• Inflammation of bursa due to constant pressure, friction,
or impact.
• “water on the knee” , bunions
• Drainage, NSAIDs
103
Dislocation
• Called luxation, when articular surfaces are forced out of
alignment.
• Requires reduction and immobilization so that articular
capsule can be repaired.
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Sprain
• Stretch/tear of ligaments of articular capsule.
• If ligaments are torn, replacement is necessary
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Normal
Hip
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Bad Hip
107
Bad Hip
108
Abnorm
al Hip
109
Femur
cut
110
Prep of
femur
111
Insert in
femur
112
Porous
hip
113
Cemente
d Hip
114
Prep of
Acet
115
Acetabul
um
replacem
ent
116
Assembl
y of
acetabul
um
117
Joint
assembly
118
Ball
Insertion
119
Repaired
Hip
120
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Reasons for Procedure
Knee replacement becomes an option for treating
a damaged knee when pain and stiffness limit
normal activities and are not relieved by other
measures, such as rest, medications, or
physical therapy. The procedure is most often
performed to:
•Alleviate knee pain and disability due to
osteoarthritis, rheumatoid arthritis, or
previous severe knee injury
•Correct a knee deformity (knee bows in or
out)
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