Final answer:
PTH stimulates osteoclast activity and promotes calcium reabsorption by the kidney tubules, increasing blood Ca2+ levels. PTH also triggers the formation of calcitriol, which increases absorption of dietary calcium in the intestines.
Step-by-step explanation:
PTH stimulates osteoclast proliferation and activity. As a result, calcium is released from the bones into the circulation, thus increasing the calcium ion concentration in the blood. PTH also promotes the reabsorption of calcium by the kidney tubules, which can affect calcium homeostasis. PTH triggers the formation of calcitriol, an active form of vitamin D, which acts on the intestines to increase absorption of dietary calcium.