TAILIEUCHUNG - Chapter 051. Menstrual Disorders and Pelvic Pain (Part 2)

Role of the hypothalamic-pituitary-gonadal axis in the etiology of amenorrhea. Gonadotropin-releasing hormone (GnRH) secretion from the hypothalamus stimulates follicle-stimulating hormone (FSH) and luteinizing hormone (LH) secretion from the pituitary to induce ovarian folliculogenesis and steroidogenesis. Ovarian secretion of estradiol and progesterone controls the shedding of the endometrium, resulting in menses and, in combination with the inhibins, provides feedback regulation of the hypothalamus and pituitary to control secretion of FSH and LH. The prevalence of amenorrhea resulting from abnormalities at each level of the reproductive system (hypothalamus, pituitary, ovary, uterus, and outflow tract) varies depending on whether amenorrhea is primary. | Chapter 051. Menstrual Disorders and Pelvic Pain Part 2 Figure 51-1 Role of the hypothalamic-pituitary-gonadal axis in the etiology of amenorrhea. Gonadotropin-releasing hormone GnRH secretion from the hypothalamus stimulates follicle-stimulating hormone FSH and luteinizing hormone LH secretion from the pituitary to induce ovarian folliculogenesis and steroidogenesis. Ovarian secretion of estradiol and progesterone controls the shedding of the endometrium resulting in menses and in combination with the inhibins provides feedback regulation of the hypothalamus and pituitary to control secretion of FSH and LH. The prevalence of amenorrhea resulting from abnormalities at each level of the reproductive system hypothalamus pituitary ovary uterus and outflow tract varies depending on whether amenorrhea is primary or secondary. PCOS polycystic ovarian syndrome. Disorders of menstrual function can be thought of in two main categories disorders of the uterus and outflow tract and disorders of ovulation. Many of the conditions that cause primary amenorrhea are congenital but go unrecognized until the time of normal puberty . genetic chromosomal and anatomic abnormalities . All causes of secondary amenorrhea can also cause primary amenorrhea. Disorders of the Uterus or Outflow Tract Abnormalities of the uterus and outflow tract typically present as primary amenorrhea. In patients with normal pubertal development and a blind vagina the differential diagnosis includes obstruction by a transverse vaginal septum or imperforate hymen mullerian agenesis Mayer-Rokitansky-Kuster-Hauser syndrome which has been associated with mutations in the WNT4 gene and androgen insensitivity syndrome AIS which is an X-linked recessive disorder that accounts for 10 of all cases of primary amenorrhea Chap. 340 . Patients with AIS have a 46 XY karyotype but because of the lack of androgen receptor responsiveness they have severe underandrogenization and female external genitalia. The absence of .

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