Articular System Flashcards
what is the purpose of a joint
connects 2 bones
functions of the joint (4)
- allow motion (pivot point)
- bare weight
- provide stability
- contains synovial fluid
define synovial joint
has no direct contact between bone ends. it is a cavity filled with synovial fluid within a sleeve-like capsule
define the stratum fibrosum
outer layer of capsule - supports and protects the joint
define the stratum synovium structure
inner layer of capsule - lined with synovial membrane made up of thick, vascular tissue
what is the main function of the stratum synovium
secret synovial fluid
articular surface for the stratum synovium
very smooth and covered with hyaline cartilage or articular cartilage
what is another name for the nonaxial joint
plane joint
what is the movement of the nonaxial joint
linear
how are the joint surface that glide over one another in the nonaxial joint
flat
when can movement not occur in the nonaxial joint
alone, it occurs secondary to other motions
example of nonaxial joint
carpals
what type of motion occurs in the uniaxial joint
angular motion occurring in one plane around one axis
3 examples of uniaxial joint
hinge joint - elbow, knee, phalanges
example of pivotal joint
radial-ulnar; proximal/distal - forearm only does supination & pronation
when does motion occur in biaxial joint
motion occurs in two different directions
3 examples and motions of biaxial joints
wrist: flexion/extension, deviation
MCP/MTP joints: flexion/extension, abduction/adduction
where does motion occur in triaxial joints
all three axes (ball and socket joint)
2 examples of triaxial joints
shoulder & hip: flexion/extension, abduction/adduction, internal/external rotation
uniaxial degree of freedom
1
biaxial degree of freedom
2
triaxial degree of freedom
3
what are the fibrous bands of ligaments made of
connective tissue
what do ligaments do
connect bone to bone
what do ligaments provide attachment for
- cartilage
- fascia
- muscles
ligaments are not elastic, they are ______
flexible/bendy
flexibility is needed to allow ligaments to ______ ______
joint motion
non-elasticity is needed to keep ______ close and provide ______ to the joint
bones, approximation
what are 4 other jobs of the ligaments
- high tensile strength
- minimal blood supply
- prolonged immobilization leads to weakness in ligaments
- define a capsular ligament: surrounds a joint
what does a capsule do to the joint
surrounds and encases
what does the capsule do to the articular surfaces of the bones
protects
the synovial membrane lines the ______ layer of the joint capsule
inner
does the synovial membrane have a blood supply?
yes
the synovial membrane secretes ______ ______
synovial fluid
characteristics of synovial fluid
thick, clear fluid
four functions of synovial fluid
- lubricates articular cartilage
- reduces friction
- shock absorption
- source of nutrition
all of this is how cartilage stays healthy
what other name is hyaline cartilage known as?
articular cartilage
where is hyaline cartilage located?
in all synovial joints
what does hyaline cartilage cover?
ends of opposing bones
does hyaline cartilage have a blood or nerve supply?
no
what is hyaline cartilage nourished by?
synovial fluid
what happens to hyaline cartilage if it is damaged?
it cannot repair itself
how is nutrition enhanced in hyaline cartilage?
enhanced by joint motion
what are two other names for fibrocartilage?
menisci or discs
what are the functions of fibrocartilage?
acts as a shock absorber, has poor blood supply
the labrum acts as fibrocartilage to which part of the body?
shoulder
what is the function of the labrum?
deepen the glenoid fossa
what are two functions of fat pads and where are they located?
- thickens the joint capsule
- takes up space in the joint
- located between the capsule and the synovial membrane
what is an example of fat pads?
knee
