Which organ's activity is largely influenced by hormones secreted by the parathyroid gland?

The activity of the kidney is largely influenced by hormones secreted by the parathyroid gland, particularly parathyroid hormone (PTH). PTH plays a critical role in regulating calcium and phosphate levels in the blood, and one of its significant effects occurs in the kidneys. When PTH is released, it promotes the reabsorption of calcium in the renal tubules, which helps to increase serum calcium levels. Additionally, PTH facilitates the excretion of phosphate by the kidneys, further contributing to the regulation of these critical minerals in the body.

This hormonal influence is crucial because the kidneys are responsible for maintaining homeostasis of calcium and phosphate levels, which are important for bone health and various metabolic processes. The actions of parathyroid hormone on the kidneys exemplify the interconnectedness of endocrine signaling and renal function in maintaining mineral balance.