Regulation of Hormone Production Quiz

PDF page 1239: Hormone production and release are often controlled by negative feedback or positive feedback, although regulation by negative feedback is more common. In negative feedback, a stimulus elicits the release of a hormone that produces a response, and once the response reaches a certain level, it sends a signal that stops additional release of the hormone. In this way, the concentration of hormones in blood is maintained within a narrow range. For example, the anterior pituitary stimulates the thyroid gland to release thyroid hormones T3 and T4. Increased levels of these hormones result in feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. Some hormones are regulated by positive feedback in which the response is amplified; an example of hormone regulation by positive feedback is the production of oxytocin during labor and childbirth as uterine contractions cause the production and release of more oxytocin. Disruptions in the mechanisms of feedback often result in deleterious consequences, such as diabetes mellitus resulting in decreased insulin production.

PDF page 1239: 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. In this way, the concentration of hormones in blood is maintained 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, as illustrated in Figure

PDF page 1239: Hormone production and release are often controlled by negative feedback or positive feedback, although regulation by negative feedback is more common. In negative feedback, a stimulus elicits the release of a hormone that produces a response, and once the response reaches a certain level, it sends a signal that stops additional release of the hormone. In this way, the concentration of hormones in blood is maintained within a narrow range. For example, the anterior pituitary stimulates the thyroid gland to release thyroid hormones T3 and T4. Increased levels of these hormones result in feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. Some hormones are regulated by positive feedback in which the response is amplified; an example of hormone regulation by positive feedback is the production of oxytocin during labor and childbirth as uterine contractions cause the production and release of more oxytocin. Disruptions in the mechanisms of feedback often result in deleterious consequences, such as diabetes mellitus resulting in decreased insulin production.

PDF page 1239: Hormone production and release are often controlled by negative feedback or positive feedback, although regulation by negative feedback is more common. In negative feedback, a stimulus elicits the release of a hormone that produces a response, and once the response reaches a certain level, it sends a signal that stops additional release of the hormone. In this way, the concentration of hormones in blood is maintained within a narrow range. For example, the anterior pituitary stimulates the thyroid gland to release thyroid hormones T3 and T4. Increased levels of these hormones result in feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. Some hormones are regulated by positive feedback in which the response is amplified; an example of hormone regulation by positive feedback is the production of oxytocin during labor and childbirth as uterine contractions cause the production and release of more oxytocin. Disruptions in the mechanisms of feedback often result in deleterious consequences, such as diabetes mellitus resulting in decreased insulin production.

PDF page 1239: Hormone production and release are often controlled by negative feedback or positive feedback, although regulation by negative feedback is more common. In negative feedback, a stimulus elicits the release of a hormone that produces a response, and once the response reaches a certain level, it sends a signal that stops additional release of the hormone. In this way, the concentration of hormones in blood is maintained within a narrow range. For example, the anterior pituitary stimulates the thyroid gland to release thyroid hormones T3 and T4. Increased levels of these hormones result in feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. Some hormones are regulated by positive feedback in which the response is amplified; an example of hormone regulation by positive feedback is the production of oxytocin during labor and childbirth as uterine contractions cause the production and release of more oxytocin. Disruptions in the mechanisms of feedback often result in deleterious consequences, such as diabetes mellitus resulting in decreased insulin production.

PDF page 1239: stimuli, hormonal stimuli, and neural stimuli.

PDF page 1240: The term “humoral” is derived from the term “humor,” which refers to bodily fluids such as blood. A humoral stimulus refers to the control of hormone release in response to changes in extracellular fluids such as blood or the ion concentration in the blood. For example, a rise in blood glucose levels triggers the pancreatic release of insulin. Insulin causes blood glucose levels to drop, which signals the pancreas to stop producing insulin in a negative feedback loop.

PDF page 1240: The term “humoral” is derived from the term “humor,” which refers to bodily fluids such as blood. A humoral stimulus refers to the control of hormone release in response to changes in extracellular fluids such as blood or the ion concentration in the blood. For example, a rise in blood glucose levels triggers the pancreatic release of insulin. Insulin causes blood glucose levels to drop, which signals the pancreas to stop producing insulin in a negative feedback loop.

PDF page 1240: The term “humoral” is derived from the term “humor,” which refers to bodily fluids such as blood. A humoral stimulus refers to the control of hormone release in response to changes in extracellular fluids such as blood or the ion concentration in the blood. For example, a rise in blood glucose levels triggers the pancreatic release of insulin. Insulin causes blood glucose levels to drop, which signals the pancreas to stop producing insulin in a negative feedback loop.

PDF page 1241: Hormonal stimuli refers to the release of a hormone in response to another hormone. A number of endocrine glands release hormones when stimulated by hormones released by other endocrine glands. For example, the hypothalamus produces hormones that stimulate the anterior portion of the pituitary gland. The anterior pituitary in turn releases hormones that regulate hormone production by other endocrine glands. The anterior pituitary releases the thyroid-stimulating hormone, which then stimulates the thyroid gland to produce the hormones T3 and T4. As blood concentrations of T3 and T4 rise, they inhibit both the pituitary and the hypothalamus in a negative feedback loop.

PDF page 1241: Hormonal stimuli refers to the release of a hormone in response to another hormone. A number of endocrine glands release hormones when stimulated by hormones released by other endocrine glands. For example, the hypothalamus produces hormones that stimulate the anterior portion of the pituitary gland. The anterior pituitary in turn releases hormones that regulate hormone production by other endocrine glands. The anterior pituitary releases the thyroid-stimulating hormone, which then stimulates the thyroid gland to produce the hormones T3 and T4. As blood concentrations of T3 and T4 rise, they inhibit both the pituitary and the hypothalamus in a negative feedback loop.

PDF page 1239: Hormone production and release are often controlled by negative feedback or positive feedback, although regulation by negative feedback is more common. In negative feedback, a stimulus elicits the release of a hormone that produces a response, and once the response reaches a certain level, it sends a signal that stops additional release of the hormone. In this way, the concentration of hormones in blood is maintained within a narrow range. For example, the anterior pituitary stimulates the thyroid gland to release thyroid hormones T3 and T4. Increased levels of these hormones result in feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. Some hormones are regulated by positive feedback in which the response is amplified; an example of hormone regulation by positive feedback is the production of oxytocin during labor and childbirth as uterine contractions cause the production and release of more oxytocin. Disruptions in the mechanisms of feedback often result in deleterious consequences, such as diabetes mellitus resulting in decreased insulin production.

PDF page 1241: In some cases, the nervous system directly stimulates endocrine glands to release hormones, which is referred to as neural stimuli. Recall that in a short-term stress response, the hormones epinephrine and norepinephrine are important for providing the bursts of energy required for the body to respond. Here, neuronal signaling from the sympathetic nervous system directly stimulates the adrenal medulla to release the hormones epinephrine and norepinephrine in response to stress.

PDF page 1241: In some cases, the nervous system directly stimulates endocrine glands to release hormones, which is referred to as neural stimuli. Recall that in a short-term stress response, the hormones epinephrine and norepinephrine are important for providing the bursts of energy required for the body to respond. Here, neuronal signaling from the sympathetic nervous system directly stimulates the adrenal medulla to release the hormones epinephrine and norepinephrine in response to stress.