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9 Cards in this Set
- Front
- Back
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Describe FSH, LH and their relation to HcG and TSH
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Both have alpha and beta sub-units. Alpha subunit is IDENTICAL in all 4.
LH is very SIMILAR to HcG. LH has a shorter half-life. Pulsatile. |
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What is the role of progesterone?
How long does corpus luteum persist? |
Prepares endometrium for implantation.
Changes endometrium from proliferative to secretory. Corpus Luteum persists up to 14 days if fertilization DOES NOT occur. Will survive longer is hCG is present (fertilization!) |
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The proliferative stage of menstrual cycle is caused how?
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Unopposed estrogen. GROWTH GROWTH GROWTH!
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What type of a peptide is GnRH?
What releases it? Where does it go? How does it travel? |
GnRH is a decapeptide. Pulsatile release
GnRH released by hypothalamus. Travels via PORTAL circulation to Anterior Pituitary. Stimulates gonadotrophs (LH and FSH). |
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TRUE/FALSE.
Estradiol stimulates LH release. |
TRUE.
Estradiol steadily increases (unopposed) during proliferative stage. Estradiol then stimulates LH, which surges (start of ovulation) |
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TRUE/FALSE
Estradiol stimulates FSH release. |
FALSE!
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What do theca cells do?
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They are external to granulosa cells. Two types of theca cells: Interna and Externa.
Theca INTERNA has LH-receptors that when triggered help stimulate the conversion of C-27 to C-19 androgen (androstenedione). Theca EXTERNA is more supportive. Theca cells are SITE OF STEROID SYNTHESIS. |
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What do granulosa cells do?
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They are stimulated by FSH (which increases aromatase enzyme levels), to aromatize C19 androgen to C18 estradiol.
Granulosa cells are responsible for follicular growth. Granulosa cells can become corpus oophorous (attached to ovum) |
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Where does GnRH come from?
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Arcuate nucleus of hypothalamus
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