Achondroplasia is an autosomal _____ (dominant/recessive) genetic trait.
In achondroplasia, the short limbs are a result of the failure of what type of bone growth?
Longitudinal bone growth (this type of bone growth accounts for the growth of the long bones in the limbs)
In achondroplasia, _____ (endochondral/membranous) bone growth is not affected.
Membranous (this type of bone growth accounts for the formation of the skull, the facial bones, and the axial skeleton)
In achondroplasia, the limbs are shorter than normal, but the _____ and _____ are normal.
Achondroplasia represents a failure of cartilage maturation resulting from a mutation in what receptor?
Fibroblast growth factor receptor
Individuals with achondroplasia have _____ (normal/decreased) life span and fertility.
True or False? Achondroplasia is associated with advanced paternal age.
A reduction in bone mass despite normal bone mineralization is a description of what disease?
What is type I osteoporosis?
Increased bone resorption as a result of decreased estrogen levels
Which therapy for osteoporosis is considered controversial due to risk of serious side effects?
Estrogen replacement therapy
What is type II osteoporosis?
Senile osteoporosis; affects men and women older than 70 years of age
Which upper extremity fracture is commonly seen in patients with osteoporosis?
Colles fracture of the distal radius
A known osteoporotic patient presents with acute back pain, loss of height and kyphosis. From what is she suffering?
Vertebral crush fractures
Name four treatments for osteoporosis.
Estrogen, calcitonin, bisphosphonates, and pulsatile parathyroid hormone
Name two methods of osteoporosis prophylaxis.
Exercise and calcium supplementation before age 30 years
A failure of normal bone resorption that leads to thickened, dense bones is a description of which disorder?
Osteopetrosis is a bone defect caused by the abnormal function of which cell type?
In patients with osteopetrosis, is the serum calcium level high, normal, or low?
In patients with osteopetrosis, is the serum phosphate level high, normal, or low?
In patients with osteopetrosis, is the alkaline phosphatase level high, normal, or low?
A genetic deficiency in carbonic anhydrase II leads to what disease?
Name three complications of osteopetrosis due to decreased space for bone marrow.
Anemia, thrombocytopenia, and infection
What neurologic lesions may result from osteopetrosis?
Cranial nerve palsies due to narrowed foramina in the skull
What is the classic x-ray finding in osteopetrosis?
Erlenmeyer flask bones that flare out
What is the disorder in which the defective mineralization of osteoid leads to soft bones?
Vitamin D deficiency in adults leads to decreased levels of what important element of bone formation?
A decreased level of calcium leads to increased levels of what hormone?
In osteomalacia/rickets, phosphate levels are _____ (increased/decreased).
Decreased (due to secondary hyperparathyroidism induced by low calcium levels)
Vitamin D deficiency in childhood causes what disorder?
What condition causes osteitis fibrosa cystica?