Chapter 8 Flashcards
Articulation
Where two bones meet
Functions of Joints
Mobility
Stability
Two Classifications
Functional
Structural
Functional Classification
Based on
-Amount of movement joint allows
3 Functional Classification
Arthro-Joint
- Synarthroses- Syn- Doesn’t Move
- Amphiarthroses- Amph- Little Movement
- Diathroses- Di- Freely Moveable
Structural Classification
Based on
- Material binding bones together
- Presence/absence of joint cavity
- -Joint Cavity- Space between joint
3 Structural Classifications
Fibrous Joint
Cartilaginous Joint
Synovial Joint
Fibrous Joints
Bones joined by dense fibrous connective tissue
No joint cavity
Most movable
-Depends on length of connective tissue fibers
3 Types of Fibrous Joints
Sutures
Syndesmoses
Gomphoses
Fibrous Joints: Sutures
- Rigid, interlocking joints
- Immovable joints for protection of brain
- Contain short connective tissues fibers
- Allow for growth during youth
- In middle age, sutures ossify and fuse
Fibrous Joints: Syndesmoses
Bones connected by ligaments
Fiber length varies so movement varies
-Little to no movement at inferior tibiofibular joint
-Large amount of movement at interosseous membrane connecting radius and ulna
Fibrous Joints: Gomphoses
- Peg-in-socket joints of teeth in alveolar sockets
- Fibrous connections
- No movement at all
Cartilaginous Joints
Bones united by cartilage
No joint cavity
Very little movable
2 Types of Cartilaginous Joints
Synchondroses
Symphyses
Cartilaginous Joints: Synchondroses
Bar/Plate of hyaline cartilage unites bones
- Temporary epiphyseal plate joints
- Cartilage of 1st rib with manubrium
Cartilaginous Joints: Symphyses
Fibrocartilage unites bone
-Hyaline cartilage present as articular cartilage
Strong flexible amphiarthroses
Synovial Joints
Bones are separated by fluid-filled joint cavity All are diarthrotic -Lots of movement Includes: -All limb joints -Most joints of body
Synovial Joints: 6 Distinguishing Features
- Articular Cartilage: Hyaline Cartilage
- Joint (synovial) Cavity
- Articular (joint) Capsule
- Synovial Fluid
- Different Types of Reinforcing Ligaments
- Nerves and Blood Vessels
Articular (Joint) Capsule
Two layers
- External Fibrous Layer
- -Dense irregular connective tissue
- Inner Synovial Membrane
- -Loose connective tissue
- -Makes synovial fluid
Synovial Fluid
- Viscous, slippery filtrate of plasma and hyaluronic acid
- Lubricates and nourishes articular cartilage
- Contains phagocytic cells to remove microbes and debris
Different Types of Reinforcing Ligaments
Capsular -Thickest Extracapsular -Outside Intracapsular -Deep
Nerves and Blood Vessels
Nerve Fibers
-Detect pain
-Monitor joint position + stretch
Capillary beds supply filtrate for synovial fluid
Other Features of Some Synovial Joints (2)
Fatty Pads Articular Discs (Menisci)
Fatty Pads
For cushioning between fibrous layer and synovial membrane or bone
Articular Discs (Menisci)
Fibrocartilage separates articular surfaces to improve “fit” of bone ends, stabilize joint, and reduce wear and tear
Structures Associated with Synovial Joints (2)
Bursae
Tendon Sheaths
Bursae
Sacs lined with synovial membrane
-Contains synovial fluid
Reduce friction
Tendon Sheaths
Elongated bursa wrapped completely around tendon subjected to friction
3 Stabilizing Factors at Synovial Joints
- Shapes of articular surfaces
- Ligament number and location
- Muscle tendons that cross joint
Synovial Joints: Movements Allowed
All muscles attach to bone or connective tissue at no fewer than two points
-Origin- Beginning
-Insertion- Ending
-Muscle contraction causes insertion to move toward origin
Movement occur along transverse, frontal, or sagittal planes
Synovial Joints: Range of Motion (3)
Uniaxial
Biaxial
Multiaxial
Uniaxial
Movement in one plane
Biaxial
Movement in two planes
Multiaxial
Movement in or around all three planes
3 Types of Movement of Synovial Joints
Gliding
Angular Movements
Rotation
Gliding Movements
One flat bone surface glides or slips over another similar surface
- Intercarpal joints
- Intertarsal joints
- Between articular processes of vertebrae
Angular Movements
Increase or decrease angle between two bones
Sagittal or Frontal Plane
Sagittal Angular Movement
Flexion -Decreases the angle of the joint Extension -Increases the angle of the joint Hyperextension -Movement beyond the anatomical position
Frontal Angular Movement
Abduction
-Movement away from the midline
Adduction
-Movement toward the midline
Rotation
Turning of bone around its own long axis -Toward the midline or away from it -Medial and lateral rotation Examples -Between C1 and C2 vertebrae -Rotation of humerus and femur
Types of Synovial Joints (6)
- Plane
- Hinge
- Pivot
- Condylar
- Saddle
- Ball-and-Socket
Knee Joint
Largest, most complex joint of body
3 Joints surrounded by a single joint cavity
-Femoropatellar Joint
-Lateral and Medial Tibiofemoral Joints
Femoropatellar Joint
Plane joint
Allows gliding motion during knee flexion
Lateral and Medial Tibiofemoral Joints
Femoral condyles with lateral and medial menisci of tibia
Allow flexion, extension, and some rotation
Knee Joint
Capsule is reinforced by muscle tendons
-Quadriceps and Semimembranosus tendons
Joint capsule is thin
Capsular and Extracapsular Ligaments
- Help prevent hyperextension of knee
- Fibular and Tibial Collateral Ligaments
Intracapsular Ligaments
-Prevent anterior-posterior displacement
-Reside outside synovial cavity
Two Types
-Anterior Cruciate Ligament
-Posterior Cruciate Ligament
Anterior Cruciate Ligament
Attaches to anterior tibia
Posterior Cruciate Ligament
Attaches to posterior tibia
Knee Joint Injuries
Absorbs great vertical force
Vulnerable to horizontal blows, especially laterally blows to extended knee
3 C’s of Knee Injuries
Collateral Ligaments
Cruciate Ligaments
Cartilages
Shoulder (Glenohumeral) Joint
Ball-and-Socket Joint
-Head of humerus with glenoid cavity of scapula
Most freely moving joint in body
-Stability sacrificed
Reinforcing Ligaments of Shoulder Joint
Primarily on anterior aspect
3 Glenohumeral Ligaments
-Weak and sometimes absent
Reinforcing Muscle Tendons of Shoulder Joint
4 Rotator Cuff Tendons encircle shoulder joint
- Subscapularis
- Infrapinatus
- Teres minor
- Supraspinatus
Elbow Joint
Articulation of radius and ulna with humerus
Hinge Joint
-Notch of Ulna with trochlea of humerus
-Flexion and extension only
Elbow Joint Ligaments
Anular Ligament -Surrounds head of radius Two Capsular ligaments restrict side-to-side movement -Ulnar Collateral Ligament -Radial Collateral Ligament
Hip (Coxal) Joint
Ball-and-socket Joint
-Head of femur articulates with acetabulum
Good range of motion
Rib of fibrocartilage- Acetabular Labrum
-Enhances depth of socket so hip dislocations are rare
Temporomandibular Joint (TMJ)
Mandibular condyle articulates with temporal bone
Two Types of movement
-Hinge- depression and elevation of mandible
-Gliding- side-to-side
Most easily dislocated joint in the body
Common Joint Injuries (4)
Cartilage Tears
Sprains
Dislocations
Subluxation
Cartilage Tears
- Due to compression and shear stress
- Fragments may cause joint to lock or bind
- Cartilage rarely repairs itself
Sprains
-Reinforcing ligaments stretched or torn
-Partial tears slowly repair heal
–Poor vascularization
3 options
-Ends sown together
-Replaced with grafts
-Time and immobilization
Dislocation (Luxation)
- Bones forced out of alignment
- Accompanied by sprains, inflammation, and difficultly moving joint
- Caused by serious falls or contact sports
- Must be reduced to treat (low swelling)
Subluxation
Partial dislocation of a joint
Inflammatory and Degenerative Conditions
Bursitis
Tendonitis
Bursitis
- Inflammation of bursa, usually caused by blow or friction
- Treated with rest and ice, anti-inflammatory drug
Tendonitis
- Inflammation of tendon sheaths typically caused by overuse
- Symptoms and treatment similar to bursitis
Arthritis
-More than 100 types of inflammatory or degenerative diseases that damage joints Symptoms -pain -stiffness -swelling of joint Chronic Forms -Osteoarthritis -Rheumatoid Arthritis -Gouty Arthritis
