Question

question 40

which of the following does not put women at risk for hypocalcemia?

a lactation
b pregnancy
c removal of theparathyroid glands
d removal of thethyroid gland

Explanation:

Define hypocalcemia and identify physiological demands

Hypocalcemia is a state of abnormally low calcium levels in the blood. Under normal physiological conditions, calcium is tightly regulated. During lactation and pregnancy, maternal calcium is heavily transferred to the fetus and into breast milk, which significantly increases the demand on maternal calcium stores and puts women at risk for hypocalcemia if dietary intake or bone resorption is insufficient.

Analyze the role of the parathyroid glands

Using the Calcium Homeostasis and Parathyroid Hormone knowledge points, we know that parathyroid hormone (PTH) is the primary hormone responsible for raising blood calcium levels when they drop too low. It stimulates osteoclasts to resorb bone, increases renal calcium reabsorption, and promotes active vitamin D synthesis. Therefore, surgical removal of the parathyroid glands (hypoparathyroidism) eliminates the body's primary mechanism for raising blood calcium, directly causing severe hypocalcemia.

Analyze the role of the thyroid gland and calcitonin

The thyroid gland produces thyroid hormones (T3 and T4) and calcitonin (from parafollicular C cells). Calcitonin acts to lower blood calcium levels by inhibiting osteoclasts and promoting renal calcium excretion. If the thyroid gland is removed, the source of calcitonin is lost. A lack of calcitonin would prevent the active lowering of blood calcium, meaning its absence does not cause hypocalcemia (and may instead lead to a mild tendency toward higher calcium levels, though calcium levels are usually maintained normally by PTH). Thus, removing the thyroid gland does not put individuals at risk for hypocalcemia.

Answer:

• (A) Lactation
• (B) Pregnancy
• (C) Removal of the parathyroid glands
• (D) Removal of the thyroid gland (Correct answer)