Summary of Joints Flashcards
Synarthrotic
bony edges close together; may interlock
- extremely strong joints
- immobile
example(s):
- bony fusion
- fibrous
- cartilaginous
Amphiarthrotic
joints with limited mobility; flexible but don’t allow for a great deal of movement
- articulating bones connected by collagen fibers or cartilage
example(s):
- fibrous
- cartilaginous
Diarthrotic
aka synovial joints; most flexible type of joint btwn bones; bones are not physically connected and can move freely in relation to e/o
- widest range of motion
- weakest joints
- typically located at ends of long bones (upper and lower appendages)
- complex joint bound by joint capsule containing synovial fluid
- multiaxial = nonaxial
- monaxial - movement in one plane
- biaxial - movement in two planes
- triaxial - movement in all three planes
bony fusion joints
2 bones fused into 1; immobile
example(s):
- epiphysis and diaphysis w/ epiphyseal line
- ilium, ischium, and pubis forming os coxa
- several bones forming sacrum
- several bones forming coccyx
synarthrotic fibrous joints
fibrous tissue binds bones together; fixed joint where collagenous fibrous connective tissue connects two bones; usually immovable with limited flexibility
- sutures: squamous, sagittal, coronal, lambdoidal
synarthrotic cartilaginous joints
type of joint where the bones are entirely joined by cartilage (hyaline cartilage or fibrocartilage); slightly moveable & lack a joint cavity
- epiphysis and diaphysis with growth plate (epiphyseal plate)
diarthrotic synovial joints
aka moveable joints; freely moving joints that allow for free movement
gliding joints
multiaxial=nonaxial diarthrotic joints
example(s):
- between carpals
- between tarsals
- between manubrium of sternum and sternal end of clavicle
- between auricular surface of sacrum and ilium of os coxa
- between superior articulating processes and inferior articulating processes of adj. vertebrae
hinge joint
monaxial - movement in one plane
example(s):
- between phalanges = interphalangeal
- elbow
- knee
- ankle
pivot joints
monaxial - movement in one plane
example(s):
- between atlas and axis (atlas pviots around ondontoid process of axis)
- radial head pivoting around radial notch of ulna
ellipsoidal joints
biaxial: movement in two planes
example(s):
- between metacarpals and proximal phalanges
- between metatarsals and proximal phalanges
- between radius and carpals
ball-n-socket joints
triaxial - movement in all three planes
example(s):
- shoulder
hip
can you feel pain in synovial joints?
no– there are no pain receptors or nerves within these joints; the pain from dislocation comes from nerves associated with outside the capsule, ligaments, and tendons
articulating cartilage
covers articulating bones
- surfaces are slick and smooth to reduce friction during joint movement
- when pressure is applied, opposing cartilage doesn’t touch
synovial fluid in between minimizes friction and acts like a sponge
what happens when a synovial joint is damaged?
joint is no longer functional
- smooth surface changes to rough, bristly collagen fibers and increased friction at joint - - due to the breakdown of cartilage matrix
synovial fluid
resembles interstitial fluid
- increased proteoglycans
- clear and viscous
total volume: 3ml
what are the functions of synovial fluid?
shock absorber, lubrication, nutrient distribution and water-disposal route
synovial fluid as a shock absorber
cushions shock in joint subj. to compression like in hip, knee, and ankle
increased pressure allows for fluid to distribute evenly across surfaces and outward toward edges of capsules
synovial fluid as lubrication
helps the joints move smoothly and w/o friction
- as cartilage is pressed, fluid squeezes out into space btwn opposing surfaces
synovial fluid in nutrient distribution and waste-disposal route
for chondrocytes of articular cartilage; circulates as joint moves
- nutrients constantly pumped into and out of cartilage matrix
meniscus
accessory structure; fibrocartilage pad between opposing articular surfaces
fat pad
accessory structure; adipose tissue, protects articular cartilage and fills in space as joint moves
ligaments
accessory structure; very strong reinforces joint capsule and connects bone to bone
what happens in a sprain?
the ligament is stretched to the point where some collagen fibers tear
what happens when excessive force happens upon a ligament?
bone breaks before ligament tears
duration for ligament repair
due to no direct blood supply and the fact that the nutrients must diffuse throughout, it takes a long time to repair
tendon
accessory structure; attaches muscle to bone; not a part of articulation; provides mechanical support as it aids in strengthening the joint
MIGHT hinder ROM
bursae
accessory structure; small, fluid-filled pockets in CT lined with synovial membrane and contains synovial fluid
- formed where tendon or ligament rubs against other tissue (similar to calluses and blisters)
- reduces friction and acts as shock absorber
bursitis
inflammation due to friction, pressure, irritation, infection, or trauma
- repetitive motion usually at shoulder
- tennis elbow, housemaid’s knee, student’s elbow
how is a bunion related to bursae?
pressure-related bursitis; usually at base of great toe (1st metatarsal)
is a joint with a greater ROM stronger or weaker?
weaker
quality/structure of collagen fibers of joint capsule and accessory ligaments
increase stability of joints
how does the presence of other bones affect joint stability?
more bones surrounding = greater stability
true or false: the tendons attached to the articulating bones affect joint stability
true
how does the shape of articulating surfaces and menisci affect joint stability?
prevents movement in specific direction
double-jointed joints
weakly stabilized as it permits a greater range of motion people with double-jointed limbs are more likely to suffer partial or complete dislocations
what is a dislocation?
articulating surfaces forced out of position
what can displacement of an articulating surface do?
potentially can damage articular cartilages, tear ligaments, or distort the joint capsule
linear motion
aka gliding; 2 opposing surfaces glide past one another
- between surfaces of articulating carpal bones
- between tarsal bones
- between clavicle and sternum
- movement almost any direction, but amount is slight
flexion
anterior-posterior plane, decrease angle between articulating elements (<180º assuming 180º is anatomical position)
extension
anterior-posterior plane, increase angle between articulating elements back to anatomical position
hyperextension
increase angle between articulating elements past anatomical position
- generally prevented by ligaments & bony processes
abduction
away from longitudinal axis (medial line) in frontal plane or from a central digit (fingers and toes)
adduction
toward longitudinal axis (medial line) in frontal plane or toward central digit
circumduction
moving arm in a loop
- hand moves in a circle, but arm does not rotate
supination
palm is turned anteriorly (anatomical position)
pronation
palm faces posterior
head rotation
right-left
limb rotation
- medial/inward rotation: anterior surface of limb turns toward long axis of trunk
- lateral/outward rotation: anterior surface of limb turns outward away from long axis of trunk
inversion
sole turns inward, elevates medial edge of sole
eversion
sole turns outward, depresses medial edge of sole
dorsiflexion
flexion of ankle, raises sole, dig in heel (as if into the ground)
plantar flexion
extension of ankle, elevates heel (as if on tiptoes)
opposition
thumb toward surface of palm or pads of digits; enables grasp and hold of objects
protraction
anterior movement in horizontal plane (jutting out jaw)
retraction
posterior movement in horizontal plane
depression
movement in inferior direction
elevation
movement in superior direction
lateral flexion
vertebral column bends to the side
rheumatism
general term indicating pain and stiffness of skeletal and/or muscular systems
arthritis
encompasses all rheumatic diseases affecting synovial joints
- always involves damage to articular cartilages
- cause can vary: bacterial, viral, injury, metabolic, severe physical stresses
osteoarthritis
degenerative joint disease (DJD)
- generally affects 60yo+
- due to cumulative wear and tear at joint surfaces
- also due to genetic factors affecting collagen formation
- preventative actions: regular exercise, physical therapy, drugs reducing inflammation (aspirin)
rheumatoid arthritis
inflammatory condition
- affects 0.5-1.0% of adult population
- some cases can be an autoimmune disease
- body attacks its own joint tissue
- possible triggers: allergies, bacteria, viruses, and genetic factors
how can joint quality be affected?
- years of use and abuse
- if not used at all, joints get stiff and there is a lack of synovial circulation
- ^decrease in ability to repair damage
- fractures easier
prevention: exercise to maintain mobility