chap 3 part 2 Flashcards
Which layer of articular cartilage is primarily densely packed collagen II?
surface layer
Which layer of articular cartilage is a thin crystalline mineral plate that functions in sealing the cartilage from bone?
deep layer (by bone)
Which layer of articular cartilage is composed of chondrocytes arranged in columns?
middle
What is the outer layer (continuous with the periosteum) of the joint capsule composed of?
fibrous dense CT
Which layer of the joint capsule contains a rich blood, lymph, and nerve supply, regenerates if damaged and is not considered an epithelial lining?
synovial layer or synovial membrane
What are the two cell types associated with the synovial layer?
Type A synovocytes and type B synovoctyes
What makes up synovial fluid?
high concentration of hyaluronan and lubricin
What are the 3 types of synovial membranes?
fibrous synovium, areolar synovium, and adipose synovium
Which type of synovial membrane has Type A and B cells and extends into the joint cavity as synovial folds and villi?
areolar synovium
T/F: adipose synovium contains Type A cells.
False; Type B cells
Which is slower and more common, appositional or interstitial cartilage growth?
appositional cartilage growth occurs much slower and is more common
Where does appositional growth originate?
perichondrium
T/F: new chondroblasts can develop from fibroblasts in the fibrous perichondrium?
true
Where does new chondrogenic perichondrium develop from?
the previous fibrous perichondrium
Where does new fibrous perichondrium develop from?
the surrounding CT
What are the 2 main functions of appositional cartilage growth?
enlarging existing cartilage and healing
What type of cartilage has more chondrocytes, less matrix, and elastic fibers?
elastic cartilage
How does elastic cartilage function?
provides more flexibility; not to stretch like a rubber band
What type of cartilage is composed of chondrocytes, fibrocytes, and collagen I fibers?
fibrocartilage
T/F: fibrocartilage has no perichondrium and is avascular.
True (with exception of a few vessels in peripheral knee menisci)
What are the 2 main functions of fibrocartilage?
provides strength (against stretch/tensile forces) and shock absorption (resists compressive forces)
What is the major limitation of fibrocartilage?
no appositional healing because there is no perichondrium
During development of fibrocartilage, tissue is initally more like what?
dense regular CT with fibroblasts
During development of fibrocartilage, the pressure from accumulating molecules changes the fibroblasts into what?
chondrocytes
During development of fibrocartilage, what type of cells/fibers develop following compressive forces?
hyaline matrix (collagen II fibers and GAGs)
If developing fibrocartilage experiences more shearing/pulling forces, what type of cells/fibers develop
collagen I
T/F: no fibroblasts remain as fibrocytes.
False; some do
What type of cartilage is a combination of dense regular CT and hyaline cartilage?
fibrocartilage
What happens to chondrocyte numbers with aging? what happens to matrix with aging? calcification of cartilage?
decrease, decrease, and increase
What type of cartilage tends to resist calcification?
elastic cartilage
When is the effect of hormones and vitamins greatest?
during original cartilage growth and development; including epiphyseal growth plates and the ossification process
What stage of arthritis benefits most from glucosamine and chondroitin supplements?
mild to moderate
T/F: healing of hyaline and elastic cartilage is much better in children than adults and typically ends up producing a lot of scar tissue.
True
When is osteoarthritis considered pathological?
before 65 years old or if its too severely
What are the 3 types of osteoarthritis?
primary, traumatic, and inherited OA
Which type of OA is caused by mutant collagen II fibers and thus not as strong?
Inherited OA
At which age do most people have at least some primary OA?
70
What is the OA cycle?
cartilage decreases leads to osteophytes develop leads to joint irritation which leads to inflammation which leads to losing more cartilage
What are the two parts of the intervertebral disc?
nucleus pulposus and annulus fibrosis
Which part of the intervertebral disc had no (or at least very few) cells after the 20s
nucleus pulposus
Which part of the intervertebral disc is composed mostly of HA (therfore much water) and collagen II? It also functions to resist compressive forces?
nucleus pulposus
What is the annulus fibrosis made of?
fibrocartilage; collagen I with some hyaline matrix; chondrocytes and fibrocytes
What is the function of the annulus fibrosis?
to support the nucleus pulposis
What change in collagen fibers occurs with age-related degenerative changes to IVD?
more collagen II and less collagen I
T/F: With age-related degenerative changes to IVD, fibrocytes produce more proteoglycans.
True
T/f: chondrocytes are able to maintain decreased aggrecans.
true
