Flashcards in Lect. 4 - prep for preg and ovulation Deck (22):
When does ovulation occur in the ovarian cycle?
day 14 of and average 28 day cycle
What roles do FSH and LF play in ovulation?
a rise in FSH and LH (sharp rise) stimulate ovulation ( they also contribute to the overall control of the menstrual cycle)
What is the source of estradiol during the folliclular phase?
granulosa cells of the developing follicle
What is estradiol responsible for in the folliclular phase?
The proliferation phase of the endometrium
What is the source of progesterone in the ovarian cycle?
Thecal cells that make up the outer part of the Graafian follicle remaining after ovulation.
What components of the Graafian follicle make up the corpus luteum?
residual theca and granulosa cells
What is the fate of the corpus luteum in the absence of fertilization?
It regresses, decreasing levels of progesterone and estradiol, resulting in the beginning of the next menstrual phase
What role does inhibin play in the menstrual cycle?
Inhibits secretion of gonadotropins, especially FSH, resulting in the regression of the corpus luteum.
3 phases of the endometrial cycle and their durations.
Menstrual phase (days 1-4 or 5)
Proliferation phase (days 4-14)
Secretory phase (days 15-28)
The menstrual phase of the endometrial cycle
Endometrial build-up from the previous cycle sloughs off (=menstrual flow).
What is the role of the spiral arteries in the menstrual phase of the endometrial cycle?
Menstruaton begins w/ vasoconstriction of the spiral arteries that have been supplying the endometrium, followed by local ischemia
What factors contribute to the vasoconstriction of the spiral arteries?
Proliferation phase of the endometrial cycle
Endometrial growth increases the endometrial thickness from 1-2mm to 8-10 by day 14.
Factor responsible for the proliferation phase of the endometrial cycle
increase levels of estradiol - secreted by the granulosa cells of the developing ovarian follicle
Secretory phase of the endometrial cycle
Endometrial growth stops, mucous glands develop more and begin secretion. Area becomes more vascularized.
Factor responsible for the secretory phase of the endometrial cycle
rising levels of progesterone, secreted by granulosa and thecal cells of the ovarian follicle
What is the major factor that leads to menopause in females?
no follicles left to produce estradiol and progesterone
What are the characteristic of the Graafian follicle immediately prior to ovulation?
oocyte arrested in diplotene of prophase 1; follicle expands; completion of meiosis I; second arrest at metaphase II; formation of stigma
What factors are involved in the process of ovulation
LH surge; increased blood flow; thickening of outer follicle layers; release of - edema, prostaglandins, histamine, vasopressin, plasminogen activator; production of metalloproteinases; secretion of HA; inflammatory action
What is ovulated?
Ovum at metaphase II; 1st polar body; zona pellucida; corona radiata; expanded cumulus oophorus
Fertilization Age system
Date age of embryo from time of fertilization