Answer:
The way calcitonin and parathyroid hormone maintain homeostasis in the body is calcitonin stimulates the kidneys to excrete calcium when calcium levels are too high, while parathyroid hormone stimulates the kidneys to absorb calcium when calcium levels are too low (option A).
Explanation:
Calcitonin and parathyroid hormone have a role in maintaining the balance of calcium and phosphorus concentrations, but their effects are opposite.
The reduction of calcium levels promoted by calcitonin is based on:
- Inhibition of intestinal absorption of calcium and bone resorption or decalcification.
- Increases the excretion of Calcium by the kidneys.
On the other hand, parathyroid hormone increases calcium levels by performing the opposite effect of calcitonin:
- It stimulates intestinal absorption and bone resorption.
- It increases renal calcium reabsorption.
Both mechanisms contribute to maintain the levels of calcium, when it is high or low in the organism, collaborating with the maintenance of the homeostasis.
The other options are not acceptable because they do not describe the correct function of calcitonin and parathyroid hormone.
