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PowerPoint® Lecture Slides prepared by Vince Austin, University of Kentucky
Joints
Human Anatomy & Physiology, Sixth Edition
Elaine N. Marieb
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
8
Joints (Articulations)
Weakest parts of the skeleton
Articulation – site where two or more bones meet
Functions of joints:
 Give the skeleton mobility
 Hold the skeleton together
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Classification by Function
A. synarthroses - immoveable (sutures in cranium)
B. amphiarthroses - slightly moveable (tibia-fibula)
C. diarthroses - freely moveable (shoulder joint)
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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:
 A. Fibrous
 B. Cartilaginous
 C. Synovial
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A. Fibrous Structural Joints
 The bones are joined by fibrous tissues
 There is no joint cavity
 Most are immovable
There are three types
a. sutures
b. syndesmoses
c. gomphoses
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Three Types of Fibrous Joints
a. Sutures
1. between cranial bones
2. very tight, thin layer of connective tissue
3. synostoses - bone replaces connective in adult
b. Syndesmoses
1. very little freedom for movement
2. interosseous membrane/ligament present
c. Gomphoses
1. one part fit tightly into the other
2. periodontal tissue holds parts firmly together
3. example: teeth in the mandible and maxillae
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-- Sutures
 Occur between the bones of the skull
 Comprised of interlocking junctions completely
filled with connective tissue fibers
 Bind bones tightly together, but allow for growth
during youth
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Figure 8.1a
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-- 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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Figure 8.1b
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-- Gomphoses
 The peg-in-socket fibrous joint between a tooth and
its alveolar socket
 The fibrous connection is the periodontal ligament
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B. Cartilaginous Joints
 Articulating bones are united by cartilage
 Lack a joint cavity
 Two types – synchondroses and symphyses
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Two Types of Cartilaginous Joints
a. Synchondrosis
1. hyaline cartilage --> bone over time
2. example: area between epiphysis & diaphysis of bone
3. example: joint between ribs and sternum
b. Symphysis
1. bones connected by disc of fibrocartilage
2. allows for slight movement (amphiarthrotic)
3. example: pubic symphysis, intervertebral discs
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-- 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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Figure 8.2a, b
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-- 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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Figure 8.2c
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C. 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
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Synovial Joints: General Structure
Figure 8.3a, b
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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: Movement
 The two muscle attachments across a joint are:
 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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Types of Synovial Joints
Plane joints
 Articular surfaces
are essentially flat
 Allow only
slipping or gliding
movements
 Only examples of
nonaxial joints
 Examples:
between carpals of
the wrist
Figure 8.7a
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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
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Figure 8.7b
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Pivot Joints
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
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Figure 8.7c
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Condyloid (Ellipsoidal) Joints
Condyloid (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
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Figure 8.7d
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Saddle Joints
Saddle joints
 Similar to condyloid joints but allow greater movement
 Each articular surface has both a concave and a convex
surface
 Example: carpometacarpal joint of the thumb
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Figure 8.7e
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Ball-and-Socket Joints
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
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Figure 8.7f
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Movements of Joints
 It is VERY important that you learn the terminology
for movements of joints. Muscles act mainly to
cause movement or fixation of a joint!!!!!!!
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Gliding Movements
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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Gliding Movement
Figure 8.5a
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Angular Movement
 Flexion — bending movement that decreases the angle of
the joint
 Extension — reverse of flexion; joint angle is increased
 Dorsiflexion and plantar flexion — up and down
movement of the foot
 Abduction — movement away from the midline
 Adduction — movement toward the midline
 Circumduction — movement describes a cone in space
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Angular Movement
Figure 8.5b
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Angular Movement
Figure 8.5c, d
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Angular Movement
Figure 8.5e, f
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Rotation
 The turning of a
bone around its own
long axis
 Examples
 Between first two
vertebrae
 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
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Special Movements
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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Knee
Largest and most complex joint of the body
Allows 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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Knee Ligaments and Tendons – Anterior View
 Tendon of the
quadriceps femoris
muscle
 Lateral and medial
patellar retinacula
 Fibular and tibial
collateral ligaments
 Patellar ligament
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Figure 8.8c
Knee – Other Supporting Structures
 Anterior cruciate ligament
 Posterior cruciate ligament
 Medial meniscus (semilunar cartilage)
 Lateral meniscus
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







Figure 8.8b
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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) that encircles the
shoulder joint and blends with the articular capsule
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Synovial Joints: Shoulder Stability
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
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Figure 8.10a
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Shoulder Stability

Figure 8.10b
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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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Hip Stability
 Acetabular labrum
 Iliofemoral
ligament
 Pubofemoral
ligament
 Ischiofemoral
ligament
 Ligamentum teres
Figure 8.11a
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Synovial Joints: Hip Stability
Figure 8.11c, d
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Sprains
The ligaments reinforcing a joint are stretched or torn
 Partially torn ligaments slowly repair themselves
 Completely torn ligaments require prompt surgical
repair
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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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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 “wear-andtear” 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
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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 chemicals are inappropriately released
 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 Enbrel (made by Amgen in Thousand Oaks) a
biological response modifier, neutralizes the harmful
properties of inflammatory chemicals
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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 anti-inflammatory
(NSAID’s) drugs, and glucocorticoids
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