I've been reading my textbook and two terms have appeared that, after a bit of looking, I still can't seem to be able to distinguish. Here's what the textbook says (McGraw Hill Bio 12, 2011):
After receiving signals from various sensors in the body, the hypothalamus secretes what are referred to as releasing hormones, which often travel to the pituitary gland. The releasing hormones stimulate the pituitary gland to secrete hormones that act on other endocrine glands. Hormones that stimulate endocrine glands to release other hormones are called tropic hormones. (pg. 394)
From the work I've done, it all seems to indicate that releasing hormones regulate the secretion of other hormones, and that tropic hormones target and stimulate other endocrine glands (to release hormones). And yet my textbook appears to use the terms separately later on as if they're related rather than identical (e.g.: "the pituitary gland is controlled by the hypothalamus via releasing hormones and it secretes tropic hormones" (pg. 396)). So are they identical? And if not, what distinguishes between them?