Articulation Notes

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Chapter 8
Articulations and Movement
Articulations or Joints
• Articulation or Joint
– Place where two bones come together
– Freely moveable to limited to no apparent
movement
– Structure correlated with movement
Classes of Joints
• Structural: Based on major connective
tissue type that binds bones
– Fibrous
– Cartilaginous
– Synovial
• Functional: Based on degree of motion
– Synarthrosis: Nonmoveable
– Amphiarthrosis: Slightly moveable
– Diarthrosis: Freely moveable
Fibrous Joints
• Characteristics
– United by fibrous
connective tissue
– Have no joint cavity
– Move little or none
• Types
– Sutures
– Syndesmoses
– Gomphoses
Syndesmoses
• Bones farther apart
than suture and
joined by ligaments
(holds bone to bone)
• Some movement may
occur
Gomphoses
• Specialized joints
• Pegs that fit into
sockets
• Inflammations
– Gingivitis
– Periodontal disease
Cartilaginous Joints
• Unite two bones by
means of cartilage
• Types
– Synchondroses
• Joined by hyaline
• Little or no movement
– Symphyses
• Fibrocartilage uniting
two bones
Concept Check
1.
What is articulation?
-point of contact b/n two bones
2. What type of joint is gomphoses? symphyses?
-Fibrous Joint in jaw (holds teeth); Fibrous Joint
3. What is the difference b/n synarthrosis,
amphiarthrosis, & diarthorsis?
-non-moveable; slightly moveable, and freely moveable
Synovial Joints
• Allow considerable
movement
• Most joints that unite bone
of appendicular skeleton
• Complex
–
–
–
–
Articular cartilage and disks
Joint cavity and capsule
Synovial membrane and fluid
Ligments and menisci
• Bursae
– Pockets of synovial fluid
*reduces friction*
– Bursitis
Types of Synovial Joints
•
•
•
•
•
•
Plane or gliding
Saddle
Hinge
Pivot
Ball-and-socket
Ellipsoid
*See Table 8.2 pg. 247
Types of Synovial Joints
• Uniaxial-movement @ 1 axis & 1 plane
• Biaxial- 2 perpendicular axis & 2
perpendicular planes
• Multiaxial- 3 or more axes & 3 or more
planes
Plane and Pivot Joints
• Plane or Gliding Joints
– Monoaxial/Slight Movement
– Example:
• Articular processes between
vertebrae (intervertebral)
• Sacroiliac
• Pivot Joints
– Monoaxial/Rotation
– Example:
• Articulation between dens of
axis and atlas
• Radius w/ ulna
Saddle and Hinge Joints
• Saddle Joints
– Biaxial/Slight Movement
– Example: Thumb
• Hinge Joints
–
–
–
–
Monoaxial
Example: Elbow, Knee
Multiaxial
Example:
• Ankle-One predominates
Ellipsoid and Ball-and-Socket
Joints
• Ellipsoid
– Modified ball-andsocket
– Biaxial
– Example:
Atlantooccipital Joint
• Ball-and-Socket
– Multiaxial
– Examples: Shoulder
and Hip joints
Types of Movement
• Gliding
• Angular
– Flexion and Extension
• Hyperextension
• Plantar and
Dorsiflexion
• Circular
– Rotation
– Pronation and
Supination
– Circumduction
Flexion and Extension
Anterior/Ventral
Posterior/Dorsal
Dorsiflexion and Plantar Flexion
heel
toes
Abduction and Adduction
“take away”
“bring together”
Rotation and
Pronation and Supination
“face down”
“lying face up”
Circumduction
Combination of
flexion, extension,
abduction, & adduction
Special Movements
• Unique to only one or two joints
– Types
• Elevation and Depression
• Protraction and Retraction
• Inversion and Eversion
Elevation and Depression
superior
inferior
Protraction and Retraction
anterior
posterior
Inversion and Eversion
medial
lateral
Concept Check
• How are joints classified?
– Structural; Degree of movement
• What type of joint makes up most of the
appendicular skeleton?
– Synovial Joints
• What components make up a synovial joint?
– Synovial membrane, joint cavity, joint capsule, articular
cartilage, ligaments, tendons, menisci, bursae
Knee Joint
• Modified hinge joint
• Menisci: Fibrocartilage articular disks
– Pad of cartilage b/n bone of a synovial joint
– Cup-shaped for stability; cushion; guide; shock absorber
• Cruciate ligaments: ACL and PCL
• Collateral ligaments: Fibular and tibial
Parts of the Knee
• Bones: Femur, Patella, Tibia, Fibula
• Muscles: Quadriceps, Hamstrings
• Actions: Flexion, Extension
• Ligaments:
–
–
–
–
Anterior Cruciate: prevents forward movement of tibia (ACL)
Posterior Cruciate: prevents forward movement of femur (PCL)
Lateral Collateral- (Fibula) LCL
Medial Collateral- (Tibia) MCL
• Tendons: Patellar Tendon (Tibia)
• Cartilage (Fibrous Articular Cartilage):
– Medial Meniscus- shock absorber
– Lateral Meniscus- shock absorber
Knee Injuries and Disorders
• Football injuries
• Bursitis
• Chondromalacia
– Softening of cartilage
• Hemarthrosis
– Blood accumulation w/n
joint cavity
– Acute; swollen knee
• “Water on the knee”
– Slower accumulation of
fluid may be caused by
bursitis
Other Knee Disorders
• Osgood Schlatter- patellar tendon pulls away
from tibia causing fracture & new bone
growth
– Associated w/ younger athletes
• Unhappy Triad - MCL, ACL, & Medial
Meniscus
– Caused by posterior, lateral blow or hit
• Dislocated Patella- medial forced w/ slightly
flexed knee
– Patella flips over
• Bucket Handle Tear- meniscus tears & piece
fills in cavity
Knee Repair
• Arthroscopy- using tools & camera to
see inside of joint
– Ligament of cartilage repair, doesn’t need
full open exposure to repair
• Arthroplasty- knee replacement
– Diseased or damaged joint
Sprains/Strains
• Sprain- ligaments
• Strain- muscle tendons
• 1st Degree- stretch
• 2nd Degree- stretch & partial tear
• 3rd Degree- complete tear
Joint Disorders
• Arthritis
– Osteoarthritis: Wear and tear
– Rheumatoid: Caused by transient infection or
autoimmune disease
• Joint infections
– Lyme disease: Bacterial infection; Tick vector
• Gout
– Metabolic disorders of unknown cause
(idiopathic; arising spontaneously - cause
unknown)
Effects of Aging on Joints
• Tissue repair slows
• Production of synovial fluid declines
• Ligaments and tendons become less
flexible
• Decrease in ROM (Range of Motion) 
Concept Check
•
–
•
–
•
–
What is the function of menisci?
Cup shaped to help with stability, cushion, & guide the
knee
What is the difference b/n a ligament & a
tendon?
Ligaments connect bone to bone; Tendons connect
muscle to bone
What is the difference b/n arthroplasty
arthroscopy?
Arthroscopy: using tools/camera to see inside the joint;
Arthoplasty: knee replacement
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