Final answer:
Hormone production and release are primarily controlled by negative feedback, which stops further release of a substance once it reaches a certain level.
Step-by-step explanation:
Hormone production and release are primarily controlled by negative feedback. In negative feedback systems, a stimulus elicits the release of a substance; once the substance reaches a certain level, it sends a signal that stops further release of the substance. This mechanism helps maintain the concentration of hormones in the blood within a narrow range.
For example, the anterior pituitary signals the thyroid to release thyroid hormones. Increasing levels of these hormones in the blood then give feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. In contrast, positive feedback loops reinforce the release of hormones, but they are less common in the regulation of hormone production and release.