The endocrine system 8: kidneys, heart and skin

Abstract The endocrine system comprises glands and tissues that produce hormones to regulate and coordinate vital bodily functions. This article - the last in an eight-part series - discusses the secondary endocrine function of the kidneys, heart and skin.

This article has been double-blind peer reviewed

In this article…

• Endocrine functions of the heart and kidneys

• The skin as an endocrine organ

• Role of the kidneys in activating vitamin D

Key points

The kidneys, heart and skin have secondary endocrine functions

A key hormone secreted by the kidneys is erythropoietin, which counters hypoxia

Hormones produced by the heart act principally on the kidneys, helping to regulate blood-sodium, extracellular volume and blood pressure

The steroid hormone calcitriol helps maintain bone structure and is produced by the kidneys through the activation of vitamin D

The skin is often overlooked as an endocrine organ, but regulates and produces various hormones, along with the prohormone vitamin D₃