Parathyroid Hormone

Question 1

Factors promoting bone growth:

Answer 1

Exercise; anabolic steroids; anti-resorptive drugs (estrogen, etc)

Question 2

Factors promoting bone resorption:

Answer 2

• weightlessness; immobility; decrease in sexual hormones/steroid deficiency

Question 3

Calcium homeostasis is maintained by the:

Answer 3

• Kidneys (excretion)
• intestines (absorption)
• bones (storage)

Question 4

Calcium homeostasis is dependent on these 2 hormones

Answer 4

Vitamin D and PTH

Question 5

MOA of PTH:

Answer 5

—> overall get/keep calcium in the blood stream!!!!

• stimulates kidney to hold onto calcium and secrete phosphate
• stimulates bones to release calcium via osteoclasts; inhibits bone formation via osteoblasts
• Long term PTH: stimulates the kidney to make more Vitamin D—> which stimulates increased GI reuptake of Calcium

Question 6

Sources of Vitamin D:

Answer 6

• fat soluble vitamin; inert until activated in the body via 2 hydroxylations
• Fatty fish
• added to milk
• supplements
• produced endogenously when UV rays from sunlight strike the skin and trigger vitamin D synthesis

Question 7

First hydroxylation of vitamin D forms ____________ and occurs in the _____________

Answer 7

Calcidiol (25-hydroxy-vitamin D)

Liver

Question 8

Second hydroxylation of vitamin D forms ____________ and occurs in the _____________

Answer 8

Calcitriol (1, 25-dihydroxy Vitamin D)—> active form

Kidney

Question 9

Best indicator for Vitamin D status

Answer 9

Serum Calcidiol

Question 10

Overproduction of calcitriol can lead to

Answer 10

• sarcoidosis
• granulomatous diseases
• lymphomas

Question 11

Vitamin D forms in food and supplements:

Answer 11

D2 (ergocalciferol)

D3 (cholecalciferol)

Question 12

Bone health density can be assessed via

Answer 12

DEXA scan

Question 13

MC cause of an abnormal calcium level

Answer 13

Increased/decreased albumin binding proteins

Question 14

Case in which you do not have to correct serum calcium levels:

Answer 14

If measurements of ionized calcium (active)

Question 15

Drugs that worsen hyperglycemia:

Answer 15

Lithium; thiazides

Question 16

Cancers MC to cause hypercalcemia of malignancy:

Answer 16

BLT and a Pickle: Breast, lung, thyroid, kidney and prostate

Question 17

Trousseau sign:

Answer 17

Carpopedal spasm (thumb adducted and phalanges extended) w/ BP cuff monitoring

Question 18

Chovotsky’s Sign:

Answer 18

Tapping on face causes facial nerve to twitch