Chapter 9 Flashcards
joint (articulation)
place of contact between bones, bone and cartilage, or bones and teeth
three structural categories of joints (classifications)
fibrous, cartilaginous, synovial
fibrous joints
has no joint cavity, occurs where bones are held together by dense regular connective tissue
cartilaginous joint
has no joint cavity, occurs where bones are joined by cartilage
synovial joint
has a joint cavity - separates articulating surfaces of bones; articulating surfaces are enclosed within connective tissue capsule and bones are attached to each other by various ligaments
functional classification of joints
synarthrosis, amphiarthrosis, diarthrosis
synarthrosis
immobile joint
amphiarthrosis
slightly mobile joint
diarthrosis
freely mobile joint
structural categories of fibrous joints (3)
gomphosis, suture, syndesmosis
gomphosis
“peg in socket”; fibrous articulations of the roots of individual teeth and alveolar processes of mandible and maxillae
periodontal membranes
synarthrosis; holds teeth firmly in place
sutures
fibrous synarthroses; irregular edges that increase stability and decrease fractures in articulations
what happens to sutures in the older adult?
dense regular connective tissue in suture ossifies, fusing skull bones together
syndesmoses
fibrous amphiarthrosis; articulating bones joined only by long strands of dense regular CT
where are syndesmoses found?
between radius and ulna, and tibia and fibula
interosseous membrane
broad, ligamentous sheet that provides pivot where radius and ulna/tibia and fibula can move relative to one another
structural categories of cartilaginous joints (2)
synchondrosis, symphysis
synchondroses
bones are joined by hyaline cartilage; functionally all synchondroses are immobile (synarthroses)
costochondral joint
joint between each bony rib and its respective costal cartilage (synchondrosis)
symphyses
pad of fibrocartilage between articulating bones; all are functionally amphiarthroses
examples of synchondroses
epiphyseal plate, costochondral joints
examples of symphyses
pubic symphysis, intervertebral disc
what is the functional classification of synovial joints?
most synovial joints are diarthrosis
examples of synovial joints
glenohumeral (shoulder) joint, temporomandibular joint, elbow/knee joint
the bones in a synovial joint are separated by a space called a:
joint cavity
common basic features of a synovial joint (4)
- has articular capsule and joint cavity
- contains synovial fluid
- articular cartilage
- ligaments, nerves, and blood vessels
articular capsule
synovial joint component that is double layered; outer fibrous layer and inner synovial membrane
outer fibrous layer of articular capsule
- made of dense connective tissue
- strengthens the joint
- prevents bones from separating
inner synovial membrane of articular capsule
- made of areolar connective tissue
- covers internal joint surfaces not covered by cartilage
- produces synovial fluid
functions of articular cartilage in synovial joints?
reduces friction, cushions, absorbs compression, prevents damage to articulating ends of bones
what does articular cartilage not have?
a perichondrium
is articular cartilage vascular or avascular?
avascular
joint cavity within synovial joint
space between articulating bones lined by synovial membrane
functions of synovial membrane within joint cavity
- secretes synovial fluid that lubricates surfaces, nourishes chondrocytes, and absorbs shock
ligaments of synovial joints
- made of dense regular connective tissue
- connects bone to bone to stabilize the joint
- extrinsic and intrinsic ligaments
extrinsic vs. intrinsic ligaments
extrinsic - physically separate from the articular capsule
intrinsic - thickening of the articular capsule; can be outside/within capsule
nerves and vessels within synovial joint
numerous within the joint; receptors for pain as well as for movement and stretch
- vascular
tendons
- made of dense regular connective tissue
- not part of synovial joint, but are around the joint
- connects muscle to bone
bursae
fibrous sac with synovial fluid that alleviates friction; found where ligaments, muscles, skin, or tendons rub together
- near/in synovial joints
tendon sheaths
elongated bursa that wraps around a tendon in areas of excess friction; more common in wrist and ankle
fat pads
protective packing material
synovial joint movements are all:
diarthrosis
different degrees of motion (3)
uniaxial - movement in one plane/axis
biaxial - two plane movement
multiaxial - multiple plane movement
synovial joint subtypes (6)
- planar
- hinge
- pivot
- condylar
- saddle
- ball-and-socket
planar
least mobile; flat surfaces
- uniaxial; “gliding”
