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
What is adduction?
Movement toward the body
What is Biaxial Joints?
- Has 2 angles but one must be Transverse axis
- Three types of axis:
a. Transverse: Flexion/Extension
b. Sagittal: Abduction/Adduction
c. Vertical: Rotation
What are 3 types of Biaxial joints?
- Condyloid
- Sellar (saddle)
- Ellipsoid
What is Condyloid joint?
- A biaxial joint
- Articular surface resembles knuckles
- Ex: Knee joint (femoral condyle); temporal mandibular joint
What is Sellar joint?
- A biaxial joint known as saddle joint
- Articular surface has a convex and concave cavity
- Ex: Carpals and metacarpals joint
*Contains Transverse (Flexion/Extension) and Sagittal (Abduction/Adduction) Axis
What is Ellipsoid Joint?
- A biaxial joint
- Articular surface has an oval convex and elliptical concave
- Contains Transverse and Sagittal axis
*Example: Junction of the radius (wrist)
What is Circumduction?
- When 2 axis are present (Using flexion/extention and abduction/adduction)
- Not the same as rotation
What is multiaxial joints?
- Articular surface has a spheroidal and socket/cup shape (ball and socket)
- 3 types of axis (transverse, sagittal, and vertical)
What is flexion?
- Decrease in the angle of the articulation bones
What is Extension?
- Increase in the angle of the articulating bones
What is Eversion?
- To move the SOLE of the foot away from the median plane
What is Inversion?
To move the SOLE of the foot toward the median plane
What is Protraction?
Forward movement
What is Retraction?
Backward movement
What is Elevation?
To move a part upward
What is Depression?
To move a part downward
What is Hilton’s law?
Nerves that supply a given joint also supply the muscles that are part of that given joint (skin also receives its blood supply)
