Osteogenesis and Joints Flashcards
(71 cards)
Which of the rolling is not a characteristic of fibrocartilage?
A.) Type II Collagen
B.) not surrounded by perichondrium
C.) Found in intervertebral discs
D.) Increased collagen in the matrix
E.) neither A nor B are characteristics of Fibrocartilage
A.) Fibrocartilage does not have Type II collagen it has Type I
Which of the following is not part of a Haversian system? A.) Periosteum B.) Lacunae C.) Lamellae D.) Volkmann Canals E.) Canalciuli
A.) Periosteum
Parathyroid hormone stimulates osteoblasts to secrete/express which of the following? A.) Osteoprotegerin B.) M-CSF C.) RANKL D.) All of the Above E) Only B and C
E.) only B and C
What signals control the aggregation of mesenchymal cells
Wnt, Hedghog, FGF, TGF-Beta
what is a blastema
Osteoblasts that are trapped by osteoid, which they secreted
Trapped osteoblasts are called what
Osteocytes
Mineralization of cartilage occurs via _______
Calcium ions
Calcification is a form of ___________ but is not a ossification
mineralization
Osteoblasts are derived from what kinds of cells
Mesenchymal cells
In intramembraneous bone formation the primary ossification center becomes a ______
trabecula
Numerous trabeculae fuse together to form what
Spongy bone
In intramembraneous bone formation osteoblasts form an epithelial-like covering over the surface of primary bone tissue and can secrete more _______ on the surface
Osteoid
In intramembranous bone formation osteoid includes ______ and _____ proteins
Collagen I and non-collagen
The initial bone formed in intramembraneous bone formation is _____
Woven bone
In Woven bone the collagen fibers are arranged ______
randomly
As collagen fibers become aligned the bone becomes
Lamellar
What is diploe
Layer of spongy bone that is enclosed by two layers of compact bone
What is it called when Lamellae become symmetrically arranged around a blood vessel forming an osteon
Haversian system
Explain Intramembraneous ossification
- ) Mesenchymal cells aggregate without a cartilage intermediate (controlled by patterning signals form polypeptides of the Wnt, hedgehog, fibroblast growth factor, and transforming growth factor- beta families)
- ) Mesenchymal cells differentiate into osteoblasts. a bone blastema is formed. Osteocytes within the core of the blastema are interconnected by cell processes forming a functional syncytium. Osteoblasts line the surface of the bone blastema
- ) Bone matrix (osteoid)- is deposited by osteoblasts. Later, Ca2+ transported by blood vessels, is sed in the mineralization process and primary bone tissue is formed. Osteoclasts initiate the modeling of the bone tissue.
Why is endochondral bone formation a misnomer
because endochondral means bone formation inside of cartilage and truly cartilage is replaced by bone
Where does the primary ossification center in endochondral bone formation occur
in future diaphysis of cartilage model
Explain endochondral bone formation
chondrocytes become hypertrophic, chondrocytes secrete vascular endothelial growth factors
blood vessels break through perichondrium, bringing in osteoprogenitor cells
hypertrophic cartilage cells undergo apoptosis, leaving behind thin strands of clarified matrix.
Osteoblasts use calcified strands as substrates for deposition of osteoid
Osteoid is calcified
note cartilage is ___________ by bone, it is not _________ into bone
replaced, transformed
the epiphyses and diaphyses are separated initially by _________
epiphyseal plate (growth plate)
