Which Process In The Body Is Primarily Controlled By Testosterone?

Affiliate xviii. The Endocrine Organization

eighteen.4 Regulation of Hormone Production

Learning Objectives

By the terminate of this section, you will be able to:

Explain how hormone production is regulated
Discuss the different stimuli that control hormone levels in the trunk

Hormone production and release are primarily controlled by negative feedback. In negative feedback systems, a stimulus elicits the release of a substance; one time the substance reaches a certain level, it sends a signal that stops farther release of the substance. In this style, 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 18.14. At that place are three mechanisms by which endocrine glands are stimulated to synthesize and release hormones: humoral stimuli, hormonal stimuli, and neural stimuli.

Figure 37.14. The anterior pituitary stimulates the thyroid gland to release thyroid hormones T3 and T4. Increasing levels of these hormones in the blood results in feedback to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland. (credit: modification of work by Mikael Häggström) — Figure 18.14.
The anterior pituitary stimulates the thyroid gland to release thyroid hormones T3 and T4. Increasing levels of these hormones in the blood results in feedback to the hypothalamus and inductive pituitary to inhibit farther signaling to the thyroid gland. (credit: modification of work past Mikael Häggström)

Hyperthyroidism is a condition in which the thyroid gland is overactive. Hypothyroidism is a status in which the thyroid gland is underactive. Which of the conditions are the following 2 patients most likely to have?

Patient A has symptoms including weight gain, cold sensitivity, low eye rate and fatigue.

Patient B has symptoms including weight loss, profuse sweating, increased heart rate and difficulty sleeping.

Humoral Stimuli

The term "humoral" is derived from the term "sense of humour," which refers to bodily fluids such equally 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 claret glucose levels triggers the pancreatic release of insulin. Insulin causes claret glucose levels to drop, which signals the pancreas to finish producing insulin in a negative feedback loop.

Hormonal Stimuli

Hormonal stimuli refers to the release of a hormone in response to some other 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 inductive pituitary in turn releases hormones that regulate hormone product by other endocrine glands. The anterior pituitary releases the thyroid-stimulating hormone, which then stimulates the thyroid gland to produce the hormones T₃ and T_four. Equally blood concentrations of T₃ and T₄ rise, they inhibit both the pituitary and the hypothalamus in a negative feedback loop.

Neural Stimuli

In some cases, the nervous organisation directly stimulates endocrine glands to release hormones, which is referred to as neural stimuli. Recall that in a brusque-term stress response, the hormones epinephrine and norepinephrine are important for providing the bursts of energy required for the torso to answer. Here, neuronal signaling from the sympathetic nervous system straight stimulates the adrenal medulla to release the hormones epinephrine and norepinephrine in response to stress.

Summary

Hormone levels are primarily controlled through negative feedback, in which rising levels of a hormone inhibit its farther release. The three mechanisms of hormonal release are humoral stimuli, hormonal stimuli, and neural stimuli. Humoral stimuli refers to the control of hormonal release in response to changes in extracellular fluid levels or ion levels. Hormonal stimuli refers to the release of hormones in response to hormones released by other endocrine glands. Neural stimuli refers to the release of hormones in response to neural stimulation.

Exercises

Hyperthyroidism is a condition in which the thyroid gland is overactive. Hypothyroidism is a condition in which the thyroid gland is underactive. Which of the atmospheric condition are the following ii patients most probable to have?
1. Patient A has symptoms including weight gain, cold sensitivity, low heart charge per unit and fatigue.
2. Patient B has symptoms including weight loss, profuse sweating, increased heart charge per unit and difficulty sleeping.
A ascent in blood glucose levels triggers release of insulin from the pancreas. This mechanism of hormone production is stimulated by:
1. humoral stimuli
2. hormonal stimuli
3. neural stimuli
4. negative stimuli
Which mechanism of hormonal stimulation would be affected if signaling and hormone release from the hypothalamus was blocked?
1. humoral and hormonal stimuli
2. hormonal and neural stimuli
3. neural and humoral stimuli
4. hormonal and negative stimuli
How is hormone product and release primarily controlled?
Compare and contrast hormonal and humoral stimuli.

Answers

Patient A has symptoms associated with decreased metabolism, and may be suffering from hypothyroidism. Patient B has symptoms associated with increased metabolism, and may exist suffering from hyperthyroidism.
A
B
Hormone production and release are primarily controlled past negative feedback. In negative feedback systems, a stimulus causes the release of a substance whose effects and so inhibit further release. In this way, the concentration of hormones in blood is maintained inside a narrow range. For example, the anterior pituitary signals the thyroid to release thyroid hormones. Increasing levels of these hormones in the blood and so feed back to the hypothalamus and anterior pituitary to inhibit further signaling to the thyroid gland.
The term humoral is derived from the term humor, which refers to bodily fluids such as claret. Humoral stimuli refer to the control of hormone release in response to changes in extracellular fluids such every bit blood or the ion concentration in the claret. 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 end producing insulin in a negative feedback loop. Hormonal stimuli refer 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 organs. For example, the hypothalamus produces hormones that stimulate the anterior pituitary. The inductive pituitary in plow releases hormones that regulate hormone production past other endocrine glands. For case, the anterior pituitary releases thyroid-stimulating hormone, which 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.

Glossary

hormonal stimuli: release of a hormone in response to another hormone
humoral stimuli: command of hormone release in response to changes in extracellular fluids such equally blood or the ion concentration in the blood
neural stimuli: stimulation of endocrine glands past the nervous system