FSH

Examples of FSH in the following topics:

• Hormonal Regulation of the Male Reproductive System

  • If the pituitary gland is removed, spermatogenesis can still be initiated by follicle-stimulating hormone (FSH) and testosterone.
  • There it stimulates the synthesis and secretion of the gonadotropins, FSH and luteinizing hormone (LH).
  • Follicle-stimulating hormone (FSH)  is released by the anterior pituitary gland.
  • Increasing the levels of FSH increases the production of spermatozoa by preventing the apoptosis of type A spermatogonia.
  • Inhibin is secreted by the Sertoli cells and acts to decrease the levels of FSH.

• Hormonal Regulation of the Female Reproductive Cycle

  • Levels of FSH peak during the first week of the follicular phase.
  • The rise in FSH recruits tertiary-stage ovarian follicles (antral follicles) for entry into the menstrual cycle.
  • Under the influence of FSH, granulosa cells begin estrogen secretion.
  • Ovulation is triggered by a spike in the amount of FSH and LH released from the pituitary gland.
  • Increased levels of FSH start recruiting follicles for the next cycle.

• Ovarian Cycle

  • During the follicular phase, follicle-stimulating hormone (FSH) is secreted by the anterior pituitary gland.
  • FSH levels begin to rise in the last few days of the previous menstrual cycle and peak during the first week of the follicular phase.
  • After ovulation, the pituitary hormones FSH and LH cause the remaining parts of the dominant follicle to transform into the corpus luteum.
  • The hormones produced by the corpus luteum suppress production of the FSH and LH, causing the corpus luteum will atrophy.
  • This in turn causes increased levels of FSH, leading to recruitment of follicles for the next cycle.

• Hormonal Methods

  • Progesterone negative feedback decreases the frequency of gonadotropin-releasing hormone (GnRH) released by the hypothalamus, which decreases the release of follicle-stimulating hormone (FSH), and greatly decreases the release of luteinizing hormone (LH) by the anterior pituitary.
  • Decreased levels of FSH inhibit follicular development, preventing an increase in estrogenl levels.
  • Estrogen negative feedback on the anterior pituitary greatly decreases the release of FSH, which inhibits follicular development and helps prevent ovulation.

• Puberty

  • GnRH signals from the hypothalamus induce pulsed secretion of LH (and to a lesser degree, FSH) at roughly one to two hour intervals.
  • Smaller increases of FSH induce an increase in the aromatase activity of these granulosa cells, which converts most of the testosterone to estradiol for secretion into the circulation.
  • Hormones include: 1 Follicle-stimulating hormone - FSH. 2 Luteinizing hormone - LH. 3 Progesterone. 4 Estrogen. 5 Hypothalamus. 6 Pituitary gland. 7 Ovary. 8 Pregnancy - hCG (Human chorionic gonadotropin). 9 Testosterone. 10 Testicle. 11 Incentives. 12 Prolactin - PRL.

• Oogenesis

  • At the start of the menstrual cycle, some 12-20 primary follicles begin to develop under the influence of elevated levels of follicle-stimulating hormone (FSH) to form secondary follicles.

• Pituitary Gland Disorders

  • In response to the releasing hormone rate, the anterior pituitary produces its hormones (TSH, ACTH, LH, FSH, GH) that stimulate effector hormone glands in the body, although prolactin acts directly on the breast gland.
  • Measurement of ACTH and growth hormone usually requires dynamic testing, whereas the other hormones (LH/FSH, prolactin, TSH) can typically be tested with basal levels.

• Testes

  • The presence of both testosterone and follicle-stimulating hormone (FSH) is needed to support spermatogenesis.

• Infertility

  • In this case synthetic FSH by injection or Clomid (Clomiphene citrate) via a pill can be given to stimulate follicles to mature in the ovaries.