Flashcards in Osteoporosis and Other Metabolic Bone Disorders Deck (33):
What happens first in bone remodeling?
The osteoclasts secrete enzymes and acids that degrade bone. They then secrete messenger molecules that activate osteoblasts.
Osteoblasts secrete _______________.
Where do osteocytes come from?
Osteoclasts are activated by the ligand ____________.
Osteoblasts are activated by the __________ pathway.
Osteoporosis predisposes people to fragility fractures. What are those?
Fractures due to minor trauma
Osteoporosis is more severe than _____________.
In wedge fractures of the vertebra, the __________ side is narrower.
anterior (leading to kyphosis)
Once you've had one fragility fracture, your risk of having another is ______________.
What is the most common critical period for bone resorption?
What formula needs to be satisfied to mineralize bone?
[Ca] x [PO4] must be greater than 24
95% of all genetic rickets is _____________.
congenital hypophosphatemic rickets (resistant to vitamin D)
The pathognomonic radiologic finding for osteomalacia is _________________.
pseudofractures – lines of demineralization where arteries press against bone
What two things are thought to cause Paget's disease?
- Genetic predisposition
- Paramyxovirus infection
________________ is usually the gene implicated in familial Paget's.
______________ ownership has been linked to Paget's disease.
What symptoms are typical of Paget's?
Paget's can cause ___________ by two ways.
deafness (the ways being ossification of the foramen through which the cochlear nerve exits and ossification of the ossicles)
Alkaline phosphatase is secreted by osteo-_________.
What are the radiologic signs of Paget's disease?
"Blade of grass" lesions in long bones and punched-out lesions in flat bones
On pathologic slides, the bone of someone with Paget's will display _______________.
disorganized trabeculae and expanded cortex
How might you hear osteoclasts histologically described?
Multinucleated giant cells
_______________ function as the mechanoreceptors in bone, increasing deposition of minerals when stress increases.
Binding to ____________ stimulates bone resorption.
What densitometry scores correspond to osteopenia and osteoporosis?
Osteopenia: less than 1.0 SD below average
Osteoporosis: less than 2.5 SD below average
What doses of calcium and vitamin D are recommended in those with osteoporosis?
1,500 mg of calcium and 1,000 units of vitamin D
Bisphosphonates and SERMs are classified as ______________ agents.
What causes vitamin D-dependent Rickets types 1 and 2?
Type 1: defect of 1-alpha hydroxylase (type 1 = 1-alpha)
Type 2: defect of vitamin D receptor
Hypophosphatemic Rickets is also called _______________.
vitamin D resistant Rickets
What are the three phases of Paget's disease?
- Osteoclast predominance (5 years; high N-telopeptides)
- Osteoblast predominance (10 years; alk phos elevated)
- Osteoclast predominance ( indefinite; high N-telopeptides)
The most frequent kind of osteoporosis fracture is __________.
The incidence of Paget's disease went down, perhaps due to the introduction of the _________ vaccine.