Joints & Movement Flashcards
major structural classifications of joints
fibrous
cartilaginous
synovial
joints classified by motion
synarthrosis - nonmovable
amphiarthrosis - slightly moveable
diarthrosis - freely moveable
fibrous joints
bones united by fibrous CT - no joint cavity - no movement: or v small amt -- a fib bc they don't move 3 types: sutures syndesmosis interossrus membrane
sutures
seams joined by dense irregular collagenous CT
irregularly locking bony edges
fontanels: newborns - membrane formed b/w these areas & allows for flexibility and rapid growth of the brain
- harden b/w 1-24 months
where are the main sutures of the skull located
coronal suture - b/w frontal & parietal bones
sagittal suture - b/w parietal bones
lambdoid suture - b/w parietal & occipital bones
syndesmosis
bones further apart than in a suture, joined by ligaments
- dense irregular CT
- some movement (most are amphiarthritic)
ex. anterior tibiofibular ligament allows for slight movement of bones at distal end
syndesmosis example
gomphoses
- peg & socket joint
- bundles of irregular collagenous (periodontal ligaments)
- joints b/w teeth and alveolar processes (sockets)
interosseus membrane
sheet of dense irregular CT
- binds neighbouring long bones and allows for amphiarthrosis
cartilaginous joints
bones united by hyaline or fibrocartilage
2 types:
synchondrosis
symphysis
synchondrosis
- joined by hyaline cartilage
- no movement (synarthrosis)
- often temporary joints and end up ossifying
ex. epiphyseal growth plates
symphysis
- bones united w fibrocartilage
- somewhat flexible bc of the fibrocartilage
ex. coxal bones w pubic symphysis, intervertebral disks
synovial joints
- contain synovial fluid: a serum filtrate that contains proteins, fats, cells , carbs (hyaluronic acid)
- allow for a great deal of motion
hyaluronic acid
decreases wear on joints, allows them to be freely moveable
articular joint capsule
continuous w outer layer of periosteum
2 parts:
fibrous membrane/capsule (outer)
synovial membrane
fibrous membrane/ capsule
contains blood vessels and nerves but doesn’t penetrate synovial membrane
thus - nutrients either diffuse through synovial membrane or are received from bone
synovial membrane
lines all bone (incl on fibrous membrane) except where articular cartilage is
articular cartilage
found on bone where bone would be touching one another
bursae
sac-like structure filled w synovial fluid
cushions movement of one body part over another
- an extension on the synovial cavity which contains synovial fluid, helping to reduce friction
tendon sheaths
tube like bursae that wrap around tendons subject to a lot of friction
menisci
crescent shaped pads of fibrocartilage found within the joint capsule b/w bones
types of synovial joints
plane hinge pivot ellipsoid/ condyloid saddle ball & socket
mnemonic for remembering types of synovial joints
place hannah's phys ed shoes back
movements of synovial joints
uniaxial
biaxial
multiaxial/triaxial
uniaxial
movement in one plane
biaxial
movement in 2 planes
multiaxial (triaxial)
movement in a variety of directions
- usually occurs at symmetrically shaped joints
plane joint
aka gliding joints 2 flat surfaces that come in contact w one another held tightly together by ligaments - biaxial or multiaxial ex tarsals
hinge joint
concave body surface articulates w convex bony surface
- uniaxial
- can flex or extend joint
ex. elbow, ankle, knee joint
pivot joint
cylindrical process rotating in a ring held in place by ligaments
- uniaxial
- allows rotation in a single axis, pronation, supination
ex. radial notch and head of radius or atlandoaxial joint b/w C1 and C2 vertebrae
ellipsoid joint
oval concave surface articulates w oval convex surface
- can’t undergo rotation bc one side is longer than the other
- biaxial
ex athlantoccipital joints, knuckle joints
saddle joint
2 saddle shaped surfaces at right angles to each other
- biaxial
ex. trapezium and metacarpal of thumb
ball and socket joint
most moveable - multiaxial
- spherical surface articulates w a concave depression
- degree of movement dependent upon deepness of socket and how spherical the ball is
large ROM but unstable
ex. hip and shoulder joints
allows for circumduction, rotation movements
types of movements at synovial joints
gliding
angular
rotation
special movements
gliding movements
usually at plane joints
- movement can be in many planes but is often limited by CT and body structures surrounding it
ex. vertebrae and carpals
angular movements
flexion / extension / hyperextension
abduction / adduction
circumduction
flexion/extension
flex- bend/decrease angle or movement in anterior direction
extension- straighten/ increase angle or movement in posterior direction
hyperextension
extends beyond anatomical position
abduction/adduction
abduct: movement away from the midline
adduct: move towards midline
radial deviation
abduction of the wrist
ulnar deviation
adduction of the wrist
circumduction
can occur at any joint that can undergo all of adduction, abduction, flexion and extension
rotation
turning a structure around its long axis
special movements
movements that are specific to only 1 or 2 joints
elevation/depression
scapula, mandible
elevation: moves a structure superiorly
depression: moves a structure inferiorly
protraction/retraction
scapula, clavicle, mandible
protraction: anterior movement in transverse plane (forward)
retraction: posterior movement in transverse plane (backwards)
inversion/eversion
intertarsal
inversion: plantar surface faces medially (think INwards)
eversion: plantar surfaces faces laterally
plantar flexion/dorsiflexion
ankle
plantar flexion: movement toward the plantar surface of foot (think PLANTing your foot)
dorsiflexion: movement away from the plantar surface
pronation/supination
rotation of forearm
pronation: palm posterior (PPP)
supination: palm anterior (hold soup)
opposition/reposition
- allows us to have manual dexterity
opposition: when the thumb and little finger are brought together - can occur w other fingers too, just req’s some flexion on their part
reposition: return of hand/fingers to normal
