Question 1

Parathyroid hormone ______ plasma calcium levels by ______ calcium resorption from bone.&#10;A) increases; increasing&#10;B) increases; decreasing&#10;C) decreases; decreasing&#10;D) decreases; decreasing.&#10;E) none of the above are true

Accepted Answer

Parathyroid hormone increases plasma calcium levels by increasing calcium resorption from bone.

Question 2

All of the following symptoms are associated with hyperthyroidism EXCEPT&#10;A) weight loss&#10;B) bradycardia&#10;C) insomnia&#10;D) heat intolerance&#10;E) muscle wasting

Accepted Answer

Hyperthyroidism is characterized by an overactive thyroid gland, which leads to an excess amount of thyroid hormone in the body. Symptoms typically include weight loss, insomnia, heat intolerance, and muscle wasting. However, bradycardia (a slow heart rate) is not typically associated with hyperthyroidism. In fact, hyperthyroidism is more commonly associated with tachycardia (a fast heart rate) due to the increased metabolic activity in the body.

Question 3

Treatment of hypothyroidism typically consists of&#10;A) beta blockers&#10;B) radioactive iodine&#10;C) large doses of iodide&#10;D) antithyroid agents such as propylthiouracil (Propyl-Thyracil) and methimazole (Tapazole)&#10;E) none of the above are true

Accepted Answer

Treatment of hypothyroidism typically involves hormone replacement therapy, not the options listed. Beta blockers, radioactive iodine, large doses of iodide, and antithyroid agents are more commonly used for hyperthyroidism or other thyroid conditions, not hypothyroidism.

Question 4

Prolonged,large doses of parathyroid hormone ______ bone breakdown,and small,intermittent amounts of parathyroid hormone ______ bone synthesis and remodeling.&#10;A) decrease; decrease&#10;B) decrease; increase&#10;C) increase; decrease&#10;D) increase; increase&#10;E) none of the above are true

Accepted Answer

Prolonged, large doses of parathyroid hormone increase bone breakdown, while small, intermittent amounts of parathyroid hormone increase bone synthesis and remodeling. This dual effect is due to the hormone's different actions depending on its concentration and exposure time.

Question 5

All of the following drug strategies can be used as part of a comprehensive plan to increase bone mineral density in postmenopausal women EXCEPT&#10;A) estrogen replacement&#10;B) bisphosphonates&#10;C) Vitamin C&#10;D) calcium supplements&#10;E) calcitonin

Accepted Answer

While Vitamin C is important for bone health, it is not a direct drug strategy for increasing bone mineral density. The other choices, estrogen replacement, bisphosphonates, calcium supplements, and calcitonin, are all drug strategies commonly used to increase bone mineral density in postmenopausal women.

Question 6

Calcimimetics like cinacalcet (Sensipar)that mimic the effects of endogenous calcium can help ____ parathyroid hormone (PTH)release,thus helping to ____ excessive bone breakdown in people with parathyroid tumors or other conditions that cause parathyroid hyperactivity.

A) increase; increase
B) increase; decrease
C) decrease; decrease
D) decrease; increase
E) none of the above; calcium and calcimimetic drugs do not affect the release or effects of PTH

Accepted Answer

Calcimimetics like cinacalcet mimic the effects of calcium on the parathyroid gland, leading to a decrease in parathyroid hormone (PTH) release. This, in turn, helps to decrease excessive bone breakdown associated with conditions of parathyroid hyperactivity.

Question 7

Bisphosphonates such as alendronate (Fosamax)and pamidronate (Aredia)reduce bone resorption in osteoporosis and similar conditions by&#10;A) inhibiting osteoclast activity&#10;B) increasing calcium absorption for the GI tract&#10;C) decreasing calcium excretion by the kidneys&#10;D) providing a dietary source of calcium&#10;E) all the above are true

Accepted Answer

Bisphosphonates work by inhibiting osteoclast activity, which reduces bone resorption in conditions such as osteoporosis. They do not affect calcium absorption or excretion, and they do not provide a dietary source of calcium. Therefore, the correct choice is A.

Question 8

Small amounts of _____ must be ingested in the diet so that the thyroid gland can synthesize thyroid hormones.&#10;A) riboflavin&#10;B) selenium&#10;C) iodine&#10;D) manganese&#10;E) magnesium

Accepted Answer

The thyroid gland requires iodine to synthesize thyroid hormones, specifically thyroxine (T4) and triiodothyronine (T3). Without sufficient iodine in the diet, the thyroid gland cannot produce enough hormones, which can lead to hypothyroidism.

Question 9

Vitamin D and several related metabolites enhance bone formation by _____ intestinal absorption of calcium and phosphate,and _____ renal excretion of calcium and phosphate.&#10;A) increasing; increasing&#10;B) increasing; decreasing&#10;C) decreasing; increasing&#10;D) decreasing; decreasing&#10;E) none of the above are true

Accepted Answer

Vitamin D and its metabolites increase intestinal absorption of calcium and phosphate by stimulating the expression of genes involved in these processes. At the same time, they decrease renal excretion of calcium and phosphate by reducing their filtration at the glomerulus and enhancing their reabsorption in the tubules. Together, these actions lead to higher levels of calcium and phosphate in the blood, which can then be used for bone formation.

Deck 31: Thyroid and Parathyroid Drugs: Agents Affecting Bone Mineralization