True or False: A paracrine action occurs when a hormone acts on the cells that produced it.

The correct answer is that a paracrine action does not occur when a hormone acts on the cells that produced it. Paracrine signaling refers to the process where a signaling molecule, often a hormone or similar substance, is released by cells and acts on nearby target cells to elicit a response. In this case, the action is local, affecting neighboring cells rather than the cells from which it was released.

In contrast, when a hormone acts on the same cells that produced it, this is referred to as autocrine signaling. Autocrine signaling involves feedback mechanisms where cells regulate their own activity through the substances they release. Recognizing the difference between paracrine and autocrine actions is essential in understanding the various means of intercellular communication in physiology.