Final answer:
The statement in question is false. Calcitonin is produced by the thyroid gland and acts to lower blood calcium levels, while parathyroid hormone (PTH) from the parathyroid glands acts to raise them; the parathyroid glands do not regulate calcitonin.
Step-by-step explanation:
The statement that calcitonin is secreted by the thyroid gland but is regulated by the parathyroid gland to ensure an adequate supply of calcium for neuromuscular and endocrine function is false.
Calcitonin is produced by the parafollicular cells of the thyroid gland and is released in response to elevated blood calcium levels. It functions to lower blood calcium levels by inhibiting osteoclast activity in the bones and stimulating the kidneys to excrete more calcium. On the other hand, parathyroid hormone (PTH), which is secreted by the parathyroid glands, has the opposite effect of calcitonin. PTH raises blood calcium levels when they are low. Although calcitonin and PTH both play roles in calcium homeostasis, calcitonin is not regulated by the parathyroid gland.