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27 Cards in this Set
- Front
- Back
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What types of endocrine cells are found in the ovary?
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Theca Cells
Granulosa Cells |
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What do Theca cells produce?
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Androstenedione
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What do Granulosa cells produce?
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Estrogen
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What are the three primary types of estrogen? and what are the differences?
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E1 estrone - predominant in menopause
E2 Estradiol -predominant in non pregnant E3 Estriol -predominant in pregnancy |
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After ovulation what happens to granulosa and theca cells?
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they become luteal cells
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What happens to primary follicles throughout a woman's life?
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Apoptosis
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What are the two components of the menstrual cycle?
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Ovarian -concerned with maturing an oocyte and its ovulation
Endometrial -creating an environment to nurture a fertilised ovum |
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What does pulsatile GnRH from the preoptic area of the hypothalamus cause in the anterior pituitary?
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Secretion of gonadotrophs: LH and FSH.
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What is the effect of FSH in the ovary?
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develops theca and granulosa cells in primary follicle
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Which cells responds predominantly to LH initially?
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Theca cells -produce androstenedione
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Which cells initially responds mostly to FSH?
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granulosa cells -produce estradiol
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_________causes _________cells to produce estradiol which causes the formation of ___________receptors on granulosa cells.
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FSH causes granulosa cells to produce estradiol which causes the formation of LH receptors on granulosa cells.
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What happens to the first follicle that develops LH receptors on the granulosa cells?
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It becomes the Dominant follicle.
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How does the dominant follicle respond to LH?
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Enhanced estrogen secretion.
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What causes the spike of LH.
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A positive feedback of estrogen(occurs at high levels) on ant. pituitary.
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Why don't other follicles develop as well?
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Inhibited by dominant follicle
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What causes the LH surge?
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2 days of elevated estrogen
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What does the LH surge do?
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Trigger ovulation:
-neutralization of action of oocyte maturation inhibitor -induces the enzyme prostoglandin endoperoxidase synthase, which results in prostoglandin, thromboxane and leukotriene production -contraction of follicular wall |
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What are the two parts of the ovarian cycle?
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Follicular and Luteal phases
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What happens hormonally during the luteal phase?
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In response to the high LH Granulosa and Theca cells switch to producing predominantly progesterone
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How long do the luteal cells last?
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If no fertilization occurs they last about 12 days, if fertilization occurs they last about 8 weeks.
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What are the 3 parts of the endometrial cycle?
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Proliferative
Secretory Atretic (menstrual) |
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What happens in proliferative phase?
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Cells lining uterus divide (responding to estradiol) forming a layer of glands and blood vessels.
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What happens in the secretory phase?
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-occurs after ovulation
-cell division halts -progesterone causes blood supply increase and secretion of acid mucin |
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What happens in the menstrual phase?
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Progesterone decreases (in absence of fertilized oocyte) causes loss of the uterine lining for 2-4 days with an increase in FSH....
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During the luteal phase what prevents new follicular maturation and ovulation?
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Progesterone from the luteal cells negatively feedsback to the hypothalamus and Ant. Pit.
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What two things does the drop in progesterone precipitate?
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The removal of inhibition on FSH and LH (and GnRH)
-causes shedding uterine lining |
