What are the major effects of parathyroid hormone?

Verified step by step guidance

Understand that parathyroid hormone (PTH) is secreted by the parathyroid glands and primarily regulates calcium levels in the blood.

Identify that one major effect of PTH is to increase blood calcium levels by stimulating osteoclasts to break down bone matrix, releasing calcium into the bloodstream.

Recognize that PTH also acts on the kidneys to reduce calcium excretion by increasing calcium reabsorption in the renal tubules.

Note that PTH promotes the activation of vitamin D (calcitriol) in the kidneys, which in turn increases calcium absorption from the intestines.

Summarize that the combined effects of PTH on bone, kidneys, and intestines work together to raise and maintain adequate blood calcium levels.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Parathyroid Hormone (PTH) Function

Parathyroid hormone is a key regulator of calcium and phosphate metabolism in the body. It is secreted by the parathyroid glands in response to low blood calcium levels and acts to restore calcium balance by targeting bones, kidneys, and the intestines.

Effects of PTH on Bone

PTH stimulates osteoclast activity indirectly, leading to bone resorption. This process releases calcium and phosphate from the bone matrix into the bloodstream, increasing serum calcium levels to maintain physiological functions.

Renal and Intestinal Actions of PTH

In the kidneys, PTH increases calcium reabsorption and decreases phosphate reabsorption, reducing phosphate levels in the blood. It also promotes activation of vitamin D, which enhances intestinal absorption of calcium, further contributing to elevated blood calcium.

Recommended video:

Guided course