Topic 4 - Arthrology Flashcards
Name the 3 “degree of movement” classifications
Synarthrosis, amphiarthrosis, diarthrosis
Synarthrosis
Immovable
Amphiarthrosis
Slightly movable
Diarthrosis
Freely movable
Classifications of joints
Degree of movement & Structure
Subcategories of structure
Fibrous, cartilaginous, synovial
Fibrous structure
Bones fastened together by thin layers of fibrous (dense) connective tissue
Classifications within fibrous structure
Syndesmosis, suture, gomphosis,
Syndesmosis
Bones joined by a fibrous band which forms an ‘interosseous ligament’ / membrane
Syndesmosis movement classification
Amphiarthrosis
Suture
Only between some bones of the skull
Bones are joined by a very __________ __________ _________ which forms a ‘sutural ligament’
Short fibrous band
Suture movement classification
Synarthrosis
Gomphosis
Articulations between tooth root and alveolus (bony socket); consists of a very short fibrous band which forms a ‘periodontal ligament’
Gomphosis movement classification
Synarthrosis
Cartilaginous structure of classification
Connection consists of hyaline cartilage or fibrocartilage
Types of cartilaginous classification
Synchondrosis & symphysis
Synchondorosis
Bones are united by a plate of hyaline cartilage
Is there both temporary and permanent synchondroses?
Yes
Synchrondosis movement classification
Synarthrosis
Examples of synchondrosis
1st rib & sternum (the rest are synovial)
Symphysis
Articular surfaces are covered by a thin layer of hyaline cartilage, which in turn is attached to a pad of fibrocartilage
Symphysis movement classification
Amphiarthrosis
Symphysis examples
Pubic symphysis, intervertebral disks
Synovial definition
Space between articulating bones filled with synovial fluid
Synovial movement classification
Diarthrosis
Synovial; freely moveable?
Yes
Structure of synovial joint
- Articular surfaces are covered with a thin layer of hyaline cartilage (articular cartilage)
- joint is encased in a joint (articular) capsule
- synovial cavity
- associated structures
What makes up the joint (articular) capsule?
- fibrous membrane/layer (capsular ligament
- synovial membrane
Fibrous membrane/layer (capsular ligament) definition
Thick, fibrous outer layer contiguous with periosteum of bones
Synovial membrane
Thin inner membrane covering all non-cartilaginous surfaces
What makes up the synovial membrane?
- fibrous layer
- cellular layer
Fibrous layer definition
Superficial (next to the fibrous membrane); collagen fibers and fibroblasts
Cellular layer def:
Deep (next to the synovial cavity); synoviocytes, blood vessels, and scattering of collagen fibers
cellular level is made up of:
- fibroblastic synovial (TypeB/fibroblast-like cells
- macrophage-like synovial (Type A) cells
Fibroblastic synovial (Type B/fibroblast-like) cells:
Next to the fibrous layer of the synovial membrane; produce hyaluronic acid component of synovial fluid
Macrophage-like synovial (Type A) cells:
Immediately next to synovial cavity; phagocytic
Synovial cavity (joint/articular cavity/space):
Interior of the joint filled with synovial fluid
Synovial fluid
Viscous, gel-like fluid composed primarily of hyaluronic acid and blood plasma
Fxns of synovial fluid
- lubrication
- cushioning/protection
- nourishment of articular cartilage
Associated structures of synovial joint:
- articular disk (meniscus)
- bursa
- other ligaments . . .
Articular disk (meniscus):
Fibrocartilage pad located between articular surfaces
Bursa:
Synovial membrane sac filled with synovial fluid (may be continuous with the synovial cavity
Other ligaments . . .
In addition to the fibrous membrane/layer of the joint capsule
Types of synovial joints
- ball-and-socket (spheroidal)
- condyloid (ellipsoidal)
- saddle
- gliding
- hinge
- pivot
How do ball-and-socket (spheroidal) synovial joints work?
- Globular/spheroidal surface of one bone articulates with a cup-shaped surface of another bone
- multiaxial
Condyloid (ellipsoidal) synovial joint
- convex oval-shaped surface of one bone articulates with a concave elliptical surface of another bone
- biaxial
Saddle (sellar) synovial joint
- each articulating surface has both concave and convex regions; surface of one bone fits the complementary surface of another
- biaxial
Gliding (arthrodial/planar/sliding) synovial joint
- articulating surfaces are nearly flat
- nonaxial
Hinge (ginglymoidal) synovial joint
- convex cylindrical surface of one bone articulates with concave cylindrical surface of another
- uniaxial
Pivot (trochoidal) synovial joint
- cylindrical pin of one bone rotates within a ring formed f bone and ligament
- uniaxial
Synovial joint movement classifications
- angular
- circular
- special movements
Angular synovial joint movement
Movements within a sagittal plane of the body
Angular movement examples
Flexion - leave anatomical position
Extension - generally return back to anatomical position
Hyperextension - extension beyond anatomical position
Dorsiflexion & plantar flexion - only at the tall rural joint of the ankle region
Types of circular synovial joint movement
- rotation
- circumduction
Circular movement: rotation
Movement of bud part around its own long axis
Circular movement: circumduction
Movement in which the distal end of the segment moves in a circle while the proximal end remains relatively fixed
Synovial joint movements: special movements (& examples of each)
Inversion & eversion - movement of the sole of the foot medially or laterally
Elevation and depression - movement of a body part upwards or downwards
Protraction and retraction - movement of a body part fwd or backward, parallel to the horiozontal surface
Arthrology clinical considerations:
- dislocation
- sprains
- bursitis
- arthritis
Dislocation def:
Displacement of a bone within a joint; partial (subluxation) or total (luxation)
Dislocation in children:
Rupture of n epiphyseal plate may occur instead of joint dislocation
What may rupture in children in a dislocation instead of joint dislocation?
Epiphyseal plate may rupture
Dislocation in elderly:
Bone fracture may occur instead of joint dislocation
Sprain def:
Over-stretching or tearing of ligamentous tissue
Strain def:
Muscle tissue damage
Bursitis
Inflammation of a bursa
What can cause bursitis?
- infection
- trauma
- continual irritation, d/t chronic motor fxn
- chronic abuse of a joint - may need modification like ergonomic furniture, etc.
Arthritis - types
- rheumatoid arthritis (RA)
- osteoarthritis (OA)
What causes rheumatoid arthritis?
Autoimmune disease involving synovial joints
How is RA characterized?
Inflammation of the synovial membrane, resulting in production of abnormal secretions (fibrous & granular) and eventual joint fusion
Fibrous secretions
Can lead to joint fusion
Granular secretions:
Can lead to destruction of articular cartilage
Rheumatoid arthritis: Bilateral? Large joints? Joints it affects: Typical age of onset? Genetic or usage dependent?
Typically yes.
No, small joints of hands and feet.
Early age of onset (middle-aged) 40-60
Genetic in nature
Osteoarthritis
Progressive degeneration of joints through ‘wear & tear’
What joints does OA typically affect?
Large weight-bearing joints, high-use joints, or joints previously involved in acute trauma
OA age of onset
Relatively late (60+)
What is OA often associated with (growing)
Development of accessory bone at periphery of joint surfaces
