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Follicles - Anatomy & Physiology (view source)
Revision as of 13:04, 9 September 2008
, 13:04, 9 September 2008→Follicular Development
*All of the other follicles undergo degeneration.
*All of the other follicles undergo degeneration.
*Ovulation of the Dominant follicles Oocyte occurs in response to an LH surge.
*Ovulation of the Dominant follicles Oocyte occurs in response to an LH surge.
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=== Atretic Follicles ===
==Function==
==Function==
*Follicular cells produce hormones important for the progression of the oestrus cycle. Theca cells produce Androstienedione which is converted to [[Endocrine_System_-_Ovaries_-_Anatomy_%26_Physiology|17β-Oestrodiol ]](E2) by the Granulosa cell enzyme Aromatase. At low levels E2 acts to negatively feedback to the hypothalamus and pituitary gland, inhibiting production of Gonadotrophin releasing Hormone (GnRH) and LH + FSH respectively. When the E2 level increases above the level of threshold it acts to stimulate gonadotrophin release. This results in the LH surge responsible for Ovulation.
*Follicular cells produce hormones important for the progression of the oestrus cycle. Theca cells produce Androstienedione which is converted to [[Endocrine_System_-_Ovaries_-_Anatomy_%26_Physiology|17β-Oestrodiol ]](E2) by the Granulosa cell enzyme Aromatase. At low levels E2 acts to negatively feedback to the hypothalamus and pituitary gland, inhibiting production of Gonadotrophin releasing Hormone (GnRH) and LH + FSH respectively. When the E2 level increases above the level of threshold it acts to stimulate gonadotrophin release. This results in the LH surge responsible for Ovulation.
*The positive feedback action of E2 leading to a surge in LH only and not FSH is due to the selective action of [[Endocrine_System_-_Ovaries_-_Anatomy_%26_Physiology|Inhibin]]. [[Endocrine_System_-_Ovaries_-_Anatomy_%26_Physiology|Inhibin]] is a hormone produced by granulosa cells that selectively inhibits FSH production by the pituitary gland.
*The positive feedback action of E2 leading to a surge in LH only and not FSH is due to the selective action of [[Endocrine_System_-_Ovaries_-_Anatomy_%26_Physiology|Inhibin]]. [[Endocrine_System_-_Ovaries_-_Anatomy_%26_Physiology|Inhibin]] is a hormone produced by granulosa cells that selectively inhibits FSH production by the pituitary gland.