Cartilage Bones Joints Flashcards
Most common cartilage?
Hyaline
Where do you find hyaline cartilage?
ribs, articular surfaces, trachea
describe hyaline cartilage
stiff, flexible, compression resistant
Cartilage separated by?
extracellular matrix
hyaline ECM contains4 things:
- collagen II
- aggrecans
- hyaluronic acid
- chondronectin
What is elastic cartilage?
hyaline + more elastin
where is elastic cartilage?
ear, epiglottis, larynx
fibrocartilage what kind of collagen?
type 1
fibrocartilage histology?
dense CT with islands of cartilage
where find fibrocartilage?
meniscus and intervertebral discs
any perichondrium in fibrocartilage?
Nope.
annulus fibrosis made of?
fibrocartilage
nucleus pulposus is collagen type?
II
replaced by fibrocartilage by age 20
where are Haversion systems?
compact bone
trabecular bone made of?
lamellae
continuous spaces
trabecular bone full of? 2 things
marrow and blood vessels
how do osteocytes get their nutrients?
in contact with marrow cavity through their processes (canaliculi)
What is in the medullary cavity?
yellow or red marrow
what is red vs. yellow marrow?
red: haemopoeitic (earlier in life)
yellow: fat cells (later in life)
yellow marrow useless?
Nope. preserves some haemopoietic cells and activate if necessary.
blood vessels in medullary cavity have what instead of capillaries?
sinusoids
bones covered with thin layer of CT inside and out called?
Periosteum
Endosteum
Periosteum contains 2 layers what are in it?
Outer: fibroblasts, vessles, collagen
Inner: osoteoprogenitors
endosteum contains?
osteoprogenitor cells for repair
where on the bone is there no periosteum or endosteum?
tendon or ligament anchors/attachments
what are Sharpey’s fibres?
collagen fibres from tendons and ligaments penetrating bone surface
arteries of bone supply?
discrete points
diaphysis, epiphysis, periosteum separately
which nervous system supplies bone? what do they follow?
sympathetic nervous system, follows blood vessels
joint surface have what? describe
hyaline cartilage
slippery, smooth, compression resistant
joint surface have periochondrium? consequences?
Nope. not supported by nutrients
synovial fluid purpose?
lubrication
nutrients for hyaline cartilage
joints are lined by what?
synovial membrane, NOT epithelium
synovial membrane lacks what 3 things? so what?
- basement membrane
- tight junctions
- desmosomes
therefore leaky
synovial fluid originates?
deep to synovial membrane
bone is inert?
dynamic tissue
what is an osteon?
Haversion system
3 cells that make/maintain bone?
osteoprogenitor
osteoblast
osteocyte
osteoprogenitor shape? where is it? renewed how?
flat
endosteum and periosteum
resting normally, renewed from bone marrow stem cells
osteoblast makes what?
osteoid to allow for hydroxy appetite deposition
osteoid is collagen type?
Type I
measure what in blood to see bone building activity?
alkaline phosphatase
inactive osteoblasts look?
flattened
purpose of osteocyte? where is it?
maintains bones
can destroy local bone to free Ca2+
entombed by bone
Descrobe osteoclasts? purpose?
Giant multinuclear cells
Remodel Bone
osteoclasts secrete?
HCl (bone) and proteases (collagen
what is marker of osteoclast activity?
tartrate-resistant acid phosphatase
osteoclasts origin related to?
granulocytes/macrophages
osteoclasts stick around?
apoptose when not needed
PTH and calcitonin on osteoclasts ?
PTH increases
calcitonin decreases osteoclasts
bone during development laid down as either:
membrane bone
endochondral bone
membrane bone forms how? which structures?
directly from mesenchyme (skull, flat bones, mandible, clavicles)
endochondral bone works how?
cartilage model then it is destroyed and replaced by bone (not calcified cartilage)
how does bone replace cartilage in development?
bone collar around diaphysis
blood vessels invade and bring bone progenitors
growth plate fuse when?
21-22 yr old
5 layers of growth plate?
R esting zone (hyaline) P roliferation (chondrocytes) M aturation (chondrocytes) H ypertrophic (dying chondros) O ssification zone
5 layers of growth plate mnemonic
Real People Make Happy Occasions
what is woven bone?
new bone during repair or development
describe woven bone
cellular
collagen
No Haversian system
woven bone lasts?
remodelled by osteoclasts and blasts
how does remodelling work?
osteoclasts make new cavities, vessels and endosteum invade and new bone!