Bone Biology and Paget's Disease

Question 1

function of osteoblasts and osteoclasts

Answer 1

osteoBlasts - Build new bone

osteoclasts - breakdown bone

Question 2

what molecule released by osteoblasts stimulates osteoclasts

Answer 2

RANKL

Question 3

how is vitamin D important in maintaining Ca2+ levels

Answer 3

Vit D is activated in calcitriol by UV light and PTH. Calcitriol increases serum Ca2+ conc by increasing absorption in gut, reducing kidney excretion and through bone resorption

Question 4

Pathopysiology of paget’s disease

Answer 4

localised disorder of increased bone turnover due to overactive osteoclasts

Question 5

problems with bone in paget’s disease

Answer 5

less compact, disoreded and more vascular –> susceptible to deformity and fracture

Question 6

age range of paget’s disease

Answer 6

> 40 y/o

Question 7

causes of paget’s

Answer 7

genetic in 15-30% of cases + environmental

Question 8

possible environmental trigger of paget’s

Answer 8

chronic viral infection within osteoclast

Question 9

presentation of paget’s disease

Answer 9

bone pain
bone deformity
heat over bone
hearing loss

Question 10

what blood test is useful in paget’s disease

Answer 10

serum alkaline phosphatase

Question 11

treatment for paget’s disease

Answer 11

one off IV bisphosponate therapy (zoledronic acid)

Question 12

true/false - immediate treatment is necessary if paget’s disease is asymptomatic in skull

Answer 12

false - don’t treat

Question 13

what other things raise alkaline phosphatase

Answer 13

being pregant (placenta)
liver disease affecting the bile ducts