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Influence of the degree of stimulation of the pituitary by gonadotropin releasing hormone on the action of inhibin and testosterone to suppress the secretion of the gonadotropins in rams.
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Institution of combined treatment with testosterone and charcoal-extracted porcine follicular fluid immediately after orchidectomy prevents the postcastration hypersecretion of follicle-stimulating hormone in the hypothalamus-lesioned rhesus monkey Macaca mulatta receiving an invariant intravenous gonadotropin-releasing hormone infusion.
Immunoneutralization of circulating inhibin in the hypohysiotropically clamped male rhesus monkey Macaca mulatta results in a selective hypersecretion of follicle-stimulating hormone. Replacement with recombinant human inhibin immediately after orchidectomy in the hypophysiotropically clamped male rhesus monkey Macaca mulatta maintains follicle-stimulating hormone FSH secretion and FSH-beta messenger ribonucleic acid levels at precastration values.
Reconciliation of the paradox that testosterone replacement prevents the postcastration hypersecretion of follicle-stimulating hormone in male rhesus monkeys Macaca mulatta with an intact central nervous system but not in hypothalamic-lesioned, gonadotropin-releasing hormone-replaced animals.
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Biochem Biophys Res Commun ; : — A role for inhibin in the regulation of follicle stimulating hormone in male domestic animals. Domest Anim Endocrinol ; 9 : — Inhibin in the male. When these drop below the ideal value the hypothalamus is signaled to begin secreting thyroid-releasing hormone again. Positive feedback mechanisms control self-perpetuating events, that is, they encourage deviation from the mean. Positive feedback systems are much less common although they do exist.
A key example occurs during childbirth. The hormone oxytocin is produced by the posterior pituitary that stimulates and enhances contractions during labor. During birth, as the baby moves through the birth canal, pressure receptors within the cervix signal the hypothalamus to stimulate the pituitary to secrete oxytocin.
Oxytocin travels to the uterus through the bloodstream, stimulating the muscles in the uterine wall to contract which in turn increases the activation of the pressure receptors and stimulates further release of oxytocin. The strength of muscle contractions intensifies until the baby is born and the stimulation of the pressure receptors is removed, which stops the release of oxytocin.
Privacy Policy. Humoral Stimuli. Hormonal Stimuli. Neural Stimuli. Exercises Hyperthyroidism is a condition in which the thyroid gland is overactive. A rise in blood glucose levels triggers release of insulin from the pancreas. This mechanism of hormone production is stimulated by: humoral stimuli hormonal stimuli neural stimuli negative stimuli Which mechanism of hormonal stimulation would be affected if signaling and hormone release from the hypothalamus was blocked?
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 be suffering from hyperthyroidism. A B Hormone production and release are primarily controlled by negative feedback. In negative feedback systems, a stimulus causes the release of a substance whose effects then inhibit further release.
Increasing levels of these hormones in the blood then 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 blood. Humoral stimuli refer to the control of hormone release in response to changes in extracellular fluids such as blood or the ion concentration in the blood.
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.
For example, the anterior pituitary releases thyroid-stimulating hormone, which stimulates the thyroid gland to produce the hormones T 3 and T 4. As blood concentrations of T 3 and T 4 rise they inhibit both the pituitary and the hypothalamus in a negative feedback loop.
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