Chapter 8: Joints Flashcards
Joint
places where bone articulate
-any area in your body where 2 bones come together
Classifying joints
- Based on the degree of movement allowed
- synarthrosis - immovable joint
- amphiarthrosis- slightly movable joint
- diarthrosis- freely movable joint - based on material found at articulation point
- fibrous- contain collagen fibers
- cartilaginous- contain cartilage
- synovial- fluid-filled synovial joint cavity separates articulating bones
Classifying Joints: Synarthrosis
immovable joint
Classifying Joints: Amphiarthrosis
slightly movable joint (if you used enough pressure)
Classifying Joints: Diarthrosis
freely movable joint
Movements allowed at joints
- Gliding
- Angular
- flexion
- extension
- hyperextension
Movement allowed at joints: Gliding
flat surfaces of 2 bone sliding back + forth across one another
Movement allowed at joints: Angular
involve changing the angle of 2 bases
(change in angle between 2 bones)
-flexion, extension, hyperextension, abduction, adduction, circumduction, rotation
Movement allowed at joints: Flexion
angle between 2 bones decreases
ex: flexion at the neck (points head downward)
Movement allowed at joints: Extension
increases angle between 2 bones
ex: straightening out the elbow or bringing you head back up
Movement allowed at joints: hyperextension
extending beyond 180 degrees (which is a straight line)
Abduction
moving away from the body, moving a bone away from the midline
ex: spread your fingers
Adduction
moving the bone toward the midline (bringing It back)
Circumduction
keeping the proximal part of a bone fixed and move the distal end in a circle
Rotation
bone spins in place along its longitudinal axis (bone spins in place)
Supination
moving hands palms up (take thumbs and turn them laterally)
Pronation
take thumbs and move them medially (palms down)
Plantar Flexion
move the foot like you’re pressing the gas (pointing toe)
Dorsiflexion
point heel (ease off gas)
Inversion
move the sole of your food medially
Eversion
moving the sole of your foot laterally
Protraction
sticking jaw out, moving a bone anteriorly along a transverse plane (protecting mandible)
Retraction
moving the bone posteriorly along a transverse plane (bringing bone back, bring jaw back)
Depression
moving a bone inferiorly
ex: open mouth; depressing mandible
Elevation
moving a bone superiorly
ex: close your mouth; elevate mandible
Opposition
touching thumb to any of the fingers
Fibrous Joints
bones joined by fibrous tissue; no joint cavity; most are synarhrotic
- sutures: skull only
- syndesmoses: bones connected by cord or sheet of fibrous tissue
- gomphoses: teeth only
Fibrous Joints: Sutures
skull only
- no movement
- protection
- dense fibrous connective tissue fills space
- penetrates bones
- ossifies in adulthood to form synostoses
Fibrous Joints: Syndesmoses
bones connected by cord (ligaments) or sheet (interosseous membrane) of fibrous tissue.
-Length of fibers determines degree of movement.
Fibrous Joints: Gomphoses
teeth only; “peg in socket” arrangement; periodontal ligaments
Cartilaginous Joints
bones united by cartilage; no joint cavity
- synchondroses
- sympheses
Cartilaginous Joints: Synchondroses
contain hyaline cartilage
- some are synarthrotic
- others amphiarthrotic; examples: epiphyseal plate; costal cartilages; many ossify and become bony joints called synostoses (which are synarthrotic) in adulthood
Cartilaginous Joints: Sympheses
contain fibrocartilage and are typically amphiarthrotic
ex: intervertebral discs; pubic symphysis
Synovial Joints
bones separated by fluid filled joint cavity; most common; diarthrotic; all limbs; most joints in body
- plane joints
- hinge joints
- pivot joints
- condyloid
- saddle joints
- ball and socket
Synovial Joints: Pane Joints
artic surfaces flat: gliding movement; intercarp/tars; nonaxial
-allow gliding
Synovial Joints: Hinge Joints
convex bone in trough; one plane- flex/extension, elbow, interphalangeal joints
-allow flexion and extension
Synovial Joints: Pivot Joints
rounded bone fits in ring on 2nd bone; unaxial; radioulnar, head
-allow rotation
Synovial Joints: Condyloid
both surfaces oval, all angular movements; wrist, “knuckles”
-allow flexion, extension, abduction, adduction, circumduction
Synovial Joints: Saddle Joints
like condyloid; thumb (where proximal phalange meets first metacarpal)
-allow flexion, extension, abduction, adduction, circumduction (but with freer movement)
Synovial Joints: Ball and Socket
spherical head, cup socket; greatest movement; hip, shoulder.
-allow all movements of condyloid plus rotation
Synovial Joints 5 Characteristics in Common
- Articular cartilage
- Articular Capsule
- Joint (articular) Cavity
- Synovial Fluid
- Ligaments
Synovial Characteristics in Common: Articular Cartilage
covers opposing bone surfaces, protection
Synovial Characteristics in Common: Articular Capsule
double-layered capsule that encloses cavity.
- Outer layer is fibrous and continuous with periostea
- inner layer is synovial membrane that produces the synovial fluid
Synovial Characteristics in Common: Joint (articular) Cavity
created by capsule; filled with synovial fluid
Synovial Characteristics in Common: Synovial Fluid
filtrate from blood and hyaluronic acid from fibroblasts from viscous synovial fluid; reduces friction; “weeping lubrication” moves fluid into and out of articular cartilages when joint is compressed/ relieved- nourishes cartilage cells
Synovial Characteristics in Common: Ligaments
strengthen/ stabilize joint
Sprain
ligaments are stretched or torn
-surgical repair often necessary
Cartilage injuries
tearing meniscus of knee; articular cartilage; epiphyseal plate.
-avascular- cannot repair itself
Dislocations
bones forced out of normal position at joint.
-repeats will occur
Inflammation
include:
bursitis (direct hit injury)
tendonitis (overuse injury)
-treat with anti-inflammatory drugs
Arthritis
100s of types; pain, stiffness, swelling
- osteoarthritis- most common, degenerative diseases; 85% of people will develop
- rheumatoid arthritis- chronic inflammatory disease; autoimmune
