Lessons 10 - 11 Flashcards
joint (articulation)
any point where two bones meet, whether or not the bones are moveable at the interface
arthrology
science of joint structure, function, and dysfunction
what does joint structure determine? (2)
direction and distance of movement
ROM
range of movement
kinesiology
the study of musculoskeletal movement
how are joint names typically named?
after the bones involved
how are joints classified?
according to the manner in which the bones are bound together, ex. bony, fibrous, cartilaginous, and synovial
functional classifications of joints: synarthrosis
immovable
functional classifications of joints: amphiarthrosis
slightly moveable
functional classifications of joints: diarthrosis
freely moving
bony, synostosis joint
an immobile joint formed when the gap between two bones ossifies, the bones ‘become one’
where can bony/synostosis joints occur?
in either fibrous or cartilaginous joints
fibrous, synarthrosis joints
adjacent bones are bound by collagen fibers that emerge from one bone and penetrate into the other
three types of fibrous joints
- sutures
- gomphoses
- syndemoses
fibrous joints: sutures
immobile, or slightly mobile fibrous joints in which short collagen fibers bind bones of the skull together
serrate suture
interlocking, wavy lines
- coronal, sagittal and lambdoid sutures
lap (squamous) suture
overlapping beveled edges
- temporal and parietal bones
plane (butt) suture
straight, non-overlapping edges
- palatine processes of the maxillae
fibrous joints: gomphosis
attachment of a tooth to its socket, held in place by fibrous periodontal ligament; slightly moveable
fibrous joints: syndesmoses
a fibrous joint at which two bones are bound by long collagen fibers, very mobile
cartilaginous joint/amphiarthrosis
two bones are linked by cartilage
two types of cartilaginous joints
- synchondroses
- symphyses
cartilaginous joints: synchondrosis
bones joined by hyaline cartilage, ex. epiphyseal plate
cartilaginous joints: symphysis
two bones joined by fibrocartilage, ex. interpubic disc, intervertebral discs
synovial joint/diarthrosis
joint in which two bones are separated by a joint cavity
- freely mobile, structurally complex
The more ROM, the _____ the joints. The less ROM, the _____ the joint.
weaker, stronger
What is the most structurally complex joint?
synovial joints
what type of joint is most likely to develop painful dysfunction?
synovial joints
articular cartilage
layer of hyaline cartilage, usually 2-3mm thick; covering the facing surfaces of two bones
joint (articular) cavity
separates articular surfaces
synovial fluid
slippery lubricant in joint cavities
what gives synovial fluid its texture?
albumin and hyaluronic acid
two functions of synovial fluid (besides friction free movement)
nourishes articular cartilage and removes waste
joint (articular) capsule
connective tissue that encloses the cavity and retains the fluid
the _____ _____ _____ of a joint is continuous with the periosteum of adjoining bones
outer fibrous capsule
the _____ _____ of joints is composed mainly of fibroblast-like cells that secrete _____ _____ and macrophages that remove debris from the joint cavity
synovial membrane, synovial fluid
joint capsules and ligaments are well supplied with _____ _____ and other sensory receptors
lamellar corpuscles
proprioception
enable brain to monitor limb movements
in a few synovial joints, _____ grows inward from the joint capsule to form a pad between articulating bones
fibrocartilage
articular disc
pad crosses the entire joint capsule
meniscus
crescent-moon pad,does not cross joint entirely
tendon
collagenous tissue strip, attaches muscles to bone
ligament
collagenous tissue strip, attaches bone to bone
bursa
fibrous sac filled with synovial fluid, located between muscles, where tendons pass over bones, or between bone and skin
bursitis
inflammation bursa, causing pain
synovial sheath
elongated cylindrical bursa wrapped around a tendon; abundant in hands and feet
three main determiners of ROM
- structure of the articular surface
- strength and tautness of ligaments and joint capsules
- action of the muscles and tendons
dislocation/luxation
caused by extreme stress on joints
- articular surfaces are forced out of position
- damages articular cartilage, ligaments, joint capsule
what joint is more prone to luxation? why?
the shoulder joint, due to its high ROM
subluxation
a partial dislocation, aka ‘double jointed’
- weakly stabilized joints that are prone to dislocation
multiaxial joints
more than two degrees of freedom (shoulder joint); ball-and-socket
biaxial joints
have two degrees of freedom; condylar, saddle, plane
monoaxial
only one degree of freedom; hinge, pivot
synovial joints: ball-and-socket
smooth, hemispherical head fits within a cup-like socket
ex. shoulder, hip
synovial joints: condylar (ellipsoid)
oval, convex surface of one bone fits into a complimentary shaped depression on the other
ex. radiocarpal joint, metacarpophalangeal joints
synovial joints: saddle
both bones have an articular surface that is shaped like a saddle, one concave, the other convex
ex. thumb
synovial joints: plane (gliding)
flat articular surfaces, bones slide over each other
ex. between carpal bones, tarsal bones
synovial joints: hinge
one bone with convex surface fits into a concave depression of another
ex. elbow, knee, fingers, toes
synovial joints: pivot
a bone spins on its longitudinal axis
ex. atlas/axis
zero position
when a joint is in its resting state at anatomical position
flexion
movement that decreases the joint angle
extension
movement that straightens a joint and returns a body part to the zero position
hyperextension
extension of a joint beyond the zero position
abduction
movement of a body part in the frontal plane away from the midline of the body
hyperabduction
raise arm to cross over back or front of the head
adduction
movement in the frontal plane back toward the midline
hyperadduction
crossing fingers, crossing ankles
elevation
movement raises a body part vertically in the frontal plane
depression
movement that lowers a body part in the same plane
protraction
the anterior movement of a body part in the transverse plane
retraction
posterior movement
circumduction
one end of an appendage remains stationary while other end makes a circular motion
rotation
movement in which a bone spins on its longitudinal axis
medial (internal) rotation
turns the bone inward
lateral (external) rotation
turns the bone outward
supination
forearm movement that turns the palm to face anteriorly or upward
pronation
forearm movement that turns palm to face either posteriorly or downward
opposition
thumb moves to approach the tip of another finger
reposition
return of thumb to the zero position
dorsiflexion
elevating toes are you do while swinging foot forward
plantar flexion
extending foot so that toes point downward as in standing on toes
inversion
movement in which soles are turned medially
eversion
movement in which the soles are turned laterally
temporomandibular joint
articulation of the condyle of the mandible with the mandibular fossa of the temporal bone
how is the synovial cavity of the TMJ divided?
into superior and inferior chambers by an articular disc
what two ligaments support the TMJ?
lateral ligament and sphenomandibular ligament
TMJ: lateral ligament
prevents posterior displacement of mandible
TMJ: sphenomandibular ligament
on the medial side of the joint
TMJ dysfunction signs and symptoms (3)
- clicking, popping, grating noises
- restricted jaw movement
- pain the intensifies with chewing and yawning
TMJ treatments
pain medication, behavior therapies
glenohumeral (humeroscapular) joint
- aka shoulder joint
hemispherical head of humerus articulates with glenoid cavity of the scapula
glenoid labrum
fibrocartilage ring that deepens glenoid cavity
supporting structures of the shoulder joints (2)
- biceps brachii, long head tendon
- rotator cuff
rotator cuff
tendons of four muscles (supraspinatus, infraspinatus, teres minor, and subscapularis) fuse to form this structure
shoulder: anterior dislocation
anterior displacement of the humerus
anterior dislocation accounts for _____ of cases
95%
shoulder separation
results from a hit to the superior surface forcing the acromion of the scapula inferiorly- dislocates the clavicle from the scapula at the acromioclavicular joint
humeroulnar joint
trochlea of the humerus joins trochlear notch of the ulna
humeroradial joint
capitulum of the humerus meets head of the radius
proximal radioulnar joint
not involved in the hinge, the head of the radius fits into the radial notch of the ulna
annular ligament
holds the proximal radioulnar joint in place by encircling the radial head
coxal joint
head of the femur inserts into acetabulum of the hip bone
- deep socket and fibrocartilage acetabular labrum assits with stability
round ligament (ligamentum teres)
attaches fovea capitis on the head of the femur to the acetabulum of the coxal bone; contains artery that supplies blood to head of femur
tibiofemoral (knee) joint
hinge joint between femur and tibia; largest and most complex diarthrosis of the body
patellofemoral joint
where the patella and patellar ligament articulate with the femur
lateral and medial menisci
two shock-absorbing cartilages in the knee joint cavity, jointed by the transverse ligament
posterior popliteal region is supported by… (2)
extracapsular ligaments and intracapsular ligaments
extracapsular ligaments
fibular (lateral) and tibial (medial) collateral ligaments; prevent knee rotating when extended
intracapular ligaments
anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL); ACL prevents hyperextension, PCL prevents posterior displacement
what are the most common injuries to the knee?
to the menisci and the ACL
why do knee injuires heal so slowly?
low or no blood supply
arthritis
a broad term for pain and inflammation of the joints
what is the most common crippling disease in the United States?
arthritis
rheumatologists
physicians who treat arthritis and other joint disorders
osteoarthritis (OA)
‘wear and tear’ arthritis, results from years of joint wear; articular cartilage softens and degenerates, bone spurs develop
gouty arthritis
crystal arthritis; occurs when uric acid or calcium salt crystals form within synovial fluid
who is gouty arthritis more common in?
women
what are some causes of gouty arthritis?
family history, increased age, alcohol consumption, food rich in purines, high fructose corn syrup
rheumatoid arthritis (RA)
autoimmune attack against the joint tissues
arthroplasty
replacement of diseased joint with artificial device called prosthesis
