Overview of Bone Diseases Flashcards
(22 cards)
The human skeleton is about ____% of body weight
12%
Bone matrix is composed of an organic component known as osteoid ____% and a mineral component ____%
35% osteoid
65% mineral component
Osteoid is made up of predominantly ___________ (type I collagen/type X collagen) with smaller amounts of glycosaminoglycans and other proteins
type I collagen
Osteopontin, a protein of osteoid, is made by _____________ (osteocytes/osteoclasts/osteoblasts)
osteoblasts
Osteopontin is also called ______________
Osteocalcin
What is the function of osteopontin?
a. It is a glycoprotein that binds to calcium in bone.
b. It is involved in bone formation and mineralization and in calcium homeostasis
It is involved in bone formation and mineralization and in calcium homeostasis
What is the function of osteonectin?
It is a glycoprotein that binds to calcium in bone
_____________ is measurable in the serum and serves as a sensitive and specific marker for osteoblast activity.
Osteocalcin
What is the formula of hydroxyapatite?
[Ca10(PO4)6(OH)2]
Hydroxyapatite serves as a repository for ___% of the body’s calcium and ___% of its phosphorus
99% calcium
85% phosphorus
The bone matrix is synthesized in one of two histologic forms that are _________ or __________
woven or lamellar
Woven bone is produced _________ (rapidly/gradually)
rapidly
The _____________ (haphazard/parallel) arrangement of collagen fibers in woven bone imparts less structural integrity.
haphazard
When is woven bone produced?
During fetal development
Fracture repair
The parallel arrangement of collagen fibers in _______ (woven/lamellar) bone imparts more structural integrity.
lamellar
Lamellar bone is produced _________ (rapidly/slowly)
slowly
In an adult, the presence of woven bone is ________ (normal/abnormal)
abnormal
Where are osteoblasts located?
On the surface of the matrix
Over time, osteoblasts may become inactive, indicated by a decrease in the ___________
cytoplasm
What is the fate of inactive osteoblasts?
They may remain on the surface of trabeculae or they might embed in the matrix become osteocytes
Osteocytes are interconnected by an intricate network
of dendritic cytoplasmic processes through tunnels
known as __________
canaliculi
What are the functions of osteoblasts?
They synthesize, transport, and assemble the matrix and regulate its mineralization
