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تسجيل

Examples of Biochemical Aids to Clinical Diagnosis: Hypothalamus–Pituitary–Gonad Axis

المؤلف:  Wilson, K., Hofmann, A., Walker, J. M., & Clokie, S. (Eds.)

المصدر:  Wilson and Walkers Principles and Techniques of Biochemistry and Molecular Biology

الجزء والصفحة:  8th E , P372

2026-06-09

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In both sexes, the hypothalamus produces gonadotropin-releasing hormone (GRH) that stimulates the pituitary to release luteinising hormone (LH) and follicle-stimulating hormone (FSH). In males, the release of LH and FSH is fairly constant, whereas in females the release is cyclical. In males, LH stimulates Leydig cells in the testes to produce testosterone, which together with FSH stimulates the production of sperm. The testosterone has a negative feedback effect on both the hypothalamus and the pituitary, thereby controlling the release of GRH. The testosterone acts on various body tissues to give male characteristics. In females, FSH acts on the ovaries to produce both oestradiol and the development of the follicle. The oestradiol and LH then act to stimulate ovulation. Oestradiol has a negative feedback effect on the hypothalamus and the pituitary and acts on body tissues to produce female characteristics.