Complete each sentence describing the hormonal control of calcium homeostasis. Labels can be used more than once. When levels of blood calcium _____
a) decrease, parathyroid hormone (PTH) is released from the parathyroid glands.
b) increase, calcitonin is released from the thyroid gland.
c) decrease, calcitonin is released from the thyroid gland.
d) increase, parathyroid hormone (PTH) is released from the adrenal glands.