Zoology - Chemical Coordination and Integration Question with Solution | TestHub

The fall in blood ${\mathrm{Ca}}^{+2}$ levels is the condition which will stimulate parathyroid gland to release parathyroid hormone. This hormone exerts its effects on bones and kidneys. When calcium levels are low, parathyroid hormone is released by the parathyroid glands into the blood and causes the bones to release calcium and increase levels in the bloodstream.