Lecture 3: Mammalian Joint Morphology Flashcards
2 regional divisions of skeletal system
axial
appendicular
components of axial skeleton (4)
skull/cranium
vertebral column
ribs
sternum
components of appendicular skeleton
limb bones
joints definition
articulations that either firmly unite bones or allow specific movements between bones
what does skeletal muscle exploit to generate movement
leverage
what provides/prevents movement of body components
muscular contraction
what kind of joints are most of the limb joints
synovial
what surrounds every bone layer of synovial joint
periosteum
2 components of joint capsule
fibrous capsule
synovial membrane
synovial membrane: 2 functions
allow movement without friction
produce synovial fluid
location of synovial fluid
joint cavity
3 areas occupied by synovial fluid
synovial joints
bursae
tendon sheaths
function of articular cartilage
absorb stress
composition of synovial fluid
viscous and elastic
transudate of blood plasma
function of synovial fluid
allow articular cartilage to glide
3 types/classifications of synovial joints
simple
compound
complex
simple synovial joint: definition and examples
joint composed of only 2 bones
2 articulation surfaces separated by synovial membrane
shoulder
compound synovial joint: definition and examples
multiple elements moving but share synovial fluid in joint space
joint containing more than 2 bones
humoral/ulnar/radial
complex synovial joint: definition and example
a joint with 3 or more elements/2 joints acting as one
2 joint capsules with their own synovial fluid
usually have meniscus/disc
stifle
where does synovial fluid come from
transudate (blood plasma)
3 types of fibrous joints
suture
syndesmosis
gomphosis
suture: definition, functions, characteristics
narrow, rigid fibrous joint
allow growth but not much movement
eventually fuse with age
unites most bones of skull
syndesmosis: definition, functions, characteristics
fibrous joint with some flexibility
found between parallel bones (tibia and fibula, ulna and radius)
contain interosseous membrane to prevent bones from being pulled apart
gomphosis aka
dento alveolar joint
gomphosis: definition, functions
hold teeth in jaw
root of tooth is anchored across gap by peridontal ligaments
ruffini endings: definition, location, function
receptors found in dermis/skin
respond to skin stretch and register the speed and direction of movement
golgi tendon organs: definition, location, function
proprioceptors that mediate position sense
mediate TENSION in large muscles
located in tendon –> near junction of tendon and muscle
simple/free nerve endings: definition, location, function
located at attachments of capsules and ligaments
terminals of unmyelinated and thinly myelinated nociceptive axons
senses PAIN
8 types of neuroreceptors in periosteum and ligaments
free nerve ending
cylindrical/bulbous end bulb
pacinian corpuscle
merkel’s disk
golgi tendon organ
ruffini corpuscle
hair follicle receptor
muscle spindle
pacinian corpuscle: definition, function, location
sensory receptors for rapid/deep vibration
most numerous in skin of hands and feet
muscle spindle: definition, location, function
stretch receptors inside capsule
sense muscle length and velocity
stretched when muscle lengthens
hair follicle: definition, function, location
located on skin
directional movement –> cause changes in tension of skin
cylindrical/bulbous end bulb: location, function, definition
thermoreception
found in mucous membranes
detect cold/flutter
role of inhibitory neurons in joints/tendons
stop motor signals/muscle contraction
what is periosteum
membrane of blood vessels and nerves that wrap around bone (delivers blood supply and sensory info)
agonist definition
contracting muscle needed to generate movement
1st participant
antagonist definition and function
muscle that relaxes during contraction of an agonist muscle
fires to slow down limb segment in order to complete a movement
what is a lever as it relates to limb joints
length of bone
3 parts of a lever
fulcrum
load
force
what is a fulcrum
usually a joint
what allows bone/lever to pivot
1st class lever: definition, type of motion generated (Example)
pivot/fulcrum lies between force and load
force and load are balance
nodding your head
2nd class lever: definition, type of motion generated (Example)
load is between the pivot/fulcrum and force
force is less than the load = mechanical advantage
standing on tip toes
3rd class lever: definition, type of motion generated (example)
load is further away from force and pivot/fulcrum
force is greater that the load, but produces large movement
bent arm (contraction of biceps to move forearm)
short vs long levers: advantage/disadvantage
short lever = faster, less force
long lever = slower, more force
physics of long lever (relationship of perpendicular distance and center of rotation)
LARGE perpendicular distance between muscle’s line of action and center of rotation of joint
where is force initially developed
skeletal muscle
how is force transferred
skeletal muscle –> tendons, aponeuroses and fascia –> bones
ligaments function
prevent excessive separation of adjacent bones
what comprises the following structures: tendons, aponeuroses, fascia, ligaments
type 1 collagen (dense CT)
what ligament holds the femoral head in place
ligament of femoral head
ball and socket joint: definition, function
rounded head fits in a concavity, permitting movement on several axes
example of ball and socket joint
coxofemoral joint (hip)
acetabulum of hip (socket) + head of femur (ball)
ligament of femoral head is a continuation of what ligament
transverse acetabular ligament
what kind of joint is coxofemoral joint (2 things)
ball and socket
synovial
5 movements of coxofemoral joint
flexion
extension
abduction (of limb)
adduction (of limb)
rotation (of limb)
hip dysplasia: definition/cause
abnormal development of coxofemoral joint
muscle mass doesn’t increase rapidly enough to account for rapid bone growth
hip dysplasia: characteristics (2)
joint laxity or instability
degenerative joint changes = acetabular bone sclerosis, thickened femoral neck, joint capsule fibrosis, subluxation/luxation of femoral head
hip dysplasia: non surgical treatments (4)
weight reduction
exercise restriction
controlled PT
NSAIDs
hip dysplasia: surgical treatment
total hip replacement
