cartilage and bone Flashcards
characteristics of connective tissue
large amounts of ECM
cells are not attached to each other
what is ECM made of
fibrous proteins and ground substance (composed of proteoglycans and multiadhesive glycoproteins)
characteristics of cartilage
solid, firm, pliable
lots of ECM
no blood vessels or nerves
rapid growth
types of cartilage cells
chondrocytes, chondroblasts
where are chondrocytes found
lacunae
where are chondroblasts found
in perichondrium
what is the function of chondrocytes
maintain and produce ECM
chondrocyte appearance
lots of rough ER
large golgi
multiple mitochondria
what is in the cartilage ECM
cartilage specific type 2 collagens
proteoglycan aggregates
water
what are the 3 types of cartilage
hyaline
elastic
fibrocartilage
what fiber does hyaline cartilage have
type 2 collagen
what fiber does elastic cartilage have
elastic fiber
what type of fiber does fibrocartilage have
both type 1 and type 2 collagen
what are some characteristics of hyaline cartilage
-on articular surfaces of bone (help with cushioning)
-found in resp such as larynx trachea bronchi for structural support
-found in fetal skeletal tissue to help in development
-found in epiphyseal plates for bone growth
what are characteristics of elastic cartilage
-dense network of branching and anastomosing fibers
what are some characteristics of fibrocartilage
made up of chondrocytes and matrix and dense connective tissue
collagen 1 and 2
where is fibrocartilage located
intervertebral discs, menisci of stifle, symphysis pubis
where is elastic cartilage found
-found in pinna of ear, epiglottis, external acoustic meatus
types of cartilage growth
appositional and interstitial
what is appositional growth
new cartilage is formed at the surface of an existing cartilage
what is interstitial growth
the chondrocytes divide within the lacunae and the newly divided chondrocytes are in isogenous groups
what is appositional growth
chondroblasts in the inner layer of the perichondrium deposit new cartilage
outer surface of bone is covered with….
periosteum
inner surfaces of bone is covered with—
endosteum
what is the internal bone structure?
cortex= compact/dense bone
spongy bone- sponge like network called trabeculae
bone tissue contains a _______ matrix
mineralized
bone matrix consists of ____-
collagen type 1 fibrils
osteoblast function
secrete bone matrix and initiate mineralization
osteocytes are _____
mature bone cells encased in the bone matrix
osteocyte lacunae is within a network of______
canaliculi
what are functions of osteocytes
regulate movement of ca and P in and out of bone
what are bone lining cells derived from
osteoblasts
what do bone lining cells/inactive osteoblasts do?
cover bone that is not remodeling
what are osteoclasts do?
bone resorption
major classes of molecules in hyaline cartilage
collagen fibers, proteoglycans, and multiadhesive glycoproteins
hyaline cartilage is surrounded by _____ which is what type of connective tissue
perichondrium which is dense irregular
perichondrium serves as a source of _______
new cartilage cells
what is the process of cartilage development called
chondrogenesis
chondrogenesis process
- aggregation of chondroprogenitor mesenchymal cells form chondrogenic nodule
- mesenchymal tissue surrounding nodule gives rise to perichondrium
- chondroprogenitor cells differentiate to chondroblasts
- chondroblasts secrete matrix
- once matrix completely surrounds chondroblasts, it becomes chondrocyte
which bone cell is not of mesenchymal origin
osteoclasts
development stages to osteocytes
mesenchymal stem cells –> osteoprogenitor cells –> osteoblasts –> osteocytes/bone lining cells
osteoclasts are derived from
hemopoietic progenitor cells
function of osteoclast
resorb bone
osteoblast function
secrete bone matrix or osteoid
also responsible for calcification of bone matrix
histologically, newly deposited matrix is not immediate calcified so it stains
lightly
histologically, actively secreting osteoblasts are:
basophilic cytoplasm with a clear golgi apparatus
osteocytes have long cytoplasmic processes that are enclosed by_____
canaliculi
osteocytes communicate with each other and _____ via ________
osteoblasts
cytoplasmic process gap junctions
bone lining cells are derived from
osteoblasts
external surface bone lining cells
periosteal cells
internal surface bone lining cells
endosteal cells
bone lining cell function
maintenance and nutrional support of osteocytes and regulate Ca dn P movement
what is the shallow depression formed by osteoclasts as it degrades the bone matrix called?
resorption bay
inside of bone contains sponge like mesh of anastomosing spicules of bone called
trabeculae
types of bones
long, short, flat, irregular
shaft of long bones
diaphysis
expanded ends of long bones
epiphysis
flared portion between diaphysis and epiphysis
metaphysis
what is the large medullary cavity filled with
marrow
outer surface of bone is covered by _____ which is what type of tissue
periosteum
dense fibrous CT containing osteoprogenitor cells
red bone marrow consists of
blood cells in diff stages of development
yellow marrow consists of ____ and found mainly in_____
fat
adults
mature bone is composed of
osteons
osteons consist of ____ which surrounds ______
concentric lamellae surrounding osteonal (haversian) canal
how is blood supplied to the bone
nutrient arteries pass through compact bone via nutrient foramina
most of the compact bone receives blood supply
from small branches of periosteal arteries that penetrate via perforating canals which also have veins and nerves
types of joints
synovial
fibrous
cartilaginous
synovial joints allow what movement
excessive
how are articulating bones of synovial joints united
by a joint capsule that encloses a joint cavity
what is the joint capsule composed of
outer fibrous layer which is lined by synovial membrane (synovium)
what is in the joint cavity
synovial fluid secreted by synovial membrane
articulating surfaces of bone is covered by
hyaline cartilage
is articular cartilage covered by perichondrium
no
articular cartilage has how many zones and what are they
4 zones
superficial zone
intermediate zone
deep zone
calcified zone
superficial zone has
chondrocytes surrounded by type 2 collagen fibrils
intermediate zone has
chondrocytes randomly distributed in matrix
collagen fibrils are less organized
deep zone has
chondrocytes in short columns perpendicular to the surface of cartilage
calcified zone
calcified with small round chondrocytes
tidemark
line of separation between calcified zone and deep zone
what happens above the tidemark
proliferation of chondrocytes within lacunae to make new cells for interstitial growth
articular cartilage receives nourishment from
synovial fluid and underlying bone
how are articulating bones held together in fibrous joints
fibrous tissue
example of fibrous joint
sutures of cranium
what are the articulating structures of primary cartilaginous joints held by
hyaline cartilage
