ANSC 23000 Lecture Notes - Lecture 14: Corpus Luteum, Anterior Pituitary, Luteinizing Hormone
27 Nov 2018
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Day 0: one large pre-ovulatory follicle secreting estradiol. No corpus luteum producing progesterone at this time. High estradiol and low progesterone allow for a surge of luteinizing hormone (lh) and follicle. Stimulating hormone (fsh) from the anterior pituitary gland. Takes 28 hours from onset of lh surge to ovulation. Fsh remains elevated due to lack of inhibition that will eventually come from inhibin and estrogen of the growing follicle feeding back on the anterior pituitary gland. Fsh remains elevated but is slowing being reduced by inhibition by inhibin and estrogen. Corpus luteum grows in size and continues to secrete progesterone. Approximately 60-70% of new cl in lactating dairy cattle develop fluid filled cavity. Day 3: many follicles are now atretic and no longer detectable by ultrasound. Day 4: first day where largest follicle deviates from next largest follicle by acquiring more lh receptors on its granulosa cells than the subordinate follicles that go into atresia.
