SKELETAL SYSTEM JOINTS Flashcards
What are joints involved in?
- Movement
- Differential growth (stages of life)
- Transmission of force (tensile, compressive, torsion)
What are the 3 classification of joints?
- Fibrous
- Cartilaginous
- Synovial
What are 3 classes of fibrous joints?
- Sutures
- Syndesmosis
- Gomphosis
What is Cartilaginous joint?
- Articulate bone
2. Two types: Synchondroses (primary cartilginous) and Symphyses (secondary cartilginous)
What are the three classes of Synovial joint?
- Uniaxial (Hinge, pivot, and plane joint)
- Biaxial (condyloid, ellipsoid, and saddle joint)
- Multiaxial (Spheroidal joint: ball and socket)
What is fibrous joint?
- Split into three groups depending on the length of the fibers (Suture, syndesmosis, and gomphosis)
What is Sutures in fibrous joint?
- Bones-connected by dense connective tissue (skull)
2. Non-movable joint in adults (joints are extremely short)
What is Syndesmosis in fibrous joint?
- Fibrous tissues bind bones
2. Limited movement
What is Gomphosis in fibrous joint?
- Fibrous tissue anchors a tooth and bone in alveolus
2. Non-movable joint
What is Synchondroses in cartilaginous joint?
- Bones bound together by hyaline cartilage (gradually fuse together preventing movement)
- Centers of ossification appear with cartilage
- Temporal joints permit bones to grow
- Slight bending which is why toddler fall without breaking anything
- Hip
What is Symphyses in cartilaginous joint?
- Bones articular surfaces are covered by hyaline cartilage
- United by fibrocartilage
- Slightly movable
- Provide strength, absorption, and flexibility
*ribs
What does Synovial Joints contain?
- Contains Articular surface, articular capsule, and joint cavity
* elbow
What is articular surfaces in synovial joints?
- Lined by articular cartilage
2. Not continuous because a cavity is in the way
What is articular capsule in synovial joints?
- Fibrous capsule is dense collagenous fibrous tissue
- Blends with periosteum
- Inside is lined by synovial membrane ()
What is synovial membrane in synovial joints?
- Vascularized
- Smooth and Villous CT present
- CT contains elastic fibers, capillaries, nerves, and adipose tissue
*Villous CT-covered by a layer of synovial epithelium that lacks basement membrane
What are the 2 cell types of synovial epithelium in Synovial Joints?
- Type A- Phagocytic cells; more prominent in the reactive synovium
- Type B- Fibroblast like cells secrete hyaluronic acid; Predominate under normal conditions
*Reactive synovium- Falling causes swelling that causes damage to the synovium joint
What is synovial membrane in Synovial Joints?
- Lines intrarticular ligaments
- Does not line intrarticular discs
- Secretes and absorbs synovial fluid
What is synovial fluid in synovial joints?
- An ultrafiltrate from synovial capillaries
- Highly polymerized hyaluronic acid
- Glycoprotein from type B synovial cells
What is the function of synovial fluid?
- Lubrication
- Reduce friction
- Prevent erosion
- Nourishment of articular cartilage through diffusion
What occurs when there is irritation in the joints?
- Causes a reactive change of the synovium (synovial epithelial hyperplasia and neovascularization)
* Increase in white blood cells in synovial fluid indicate joint disease
What is Rheumatoid arthritis?
- Hyperactive/hyperplastic synovial membrane transformed into pannus tissue
- Invades cartilage and bone
- Symmetrical/ polyarticular joint involvement
- Systemic symptoms (fever, fatigue, weight loss, and rash)
- Advance stages causes destruction in the joint and tendons
*Starts in synovial fluid, not joint
What does stability of synovial joint depend on?
- Shape of articular surfaces
- Number
- Position
- Strength of the ligaments
What is Uniaxial joint?
- Three types:
a. Hinge (Flexion-Extension) “ginglymi”
b. Pivot (Vertical axis rotation) “Trochoid”
c. Plane (Gliding/sliding) “tight articular capsule”
What is abduction?
Movement away from the body
- Abduction of toes: To spread digits apart
- Adduction of toes: To move digits toward median plane
