1.2 Physiology of Menstruation and Decidua Flashcards
What are the 4 predominant hormones in the menstrual cycle
GnRH, FSH, LH, estrogen
It stimulates the release of LH and FSH from the anterior pituitary
GnRH
True or False. High levels of estrogen exerts a negative feedback on LH and FSh secretion
False
At what phase of the ovarian cycle is FSH secretion highest and most critical?
1st week of follicular phase
What are the 2 cycles involved in menstrual cycle?
Ovarian Cycle
Endometrial Cycle
What are the phases of the ovarian cycle
Follicular/ Preovulatory
Ovulation
Luteal
Pre-menstrual
What are the phases of the endometrial cycle
Proliferative
Secretory
Menstrual
What cells secrete FSH
granulosa cells
What cells secrete LH
theca cells
It is the most potent and abundant form of estrogen
Estradiol
Which of the ff is not an action of estradiol?
a. nitric acid production
b. proliferation of endometrial glands
c. further induction of proliferation of estrogen-converting granulosa cells
d. induction of FSH and LH receptors on granulosa cells
e. proliferation of stromal and epithelial cells
f. none of the above
None of the above. Action nya yan lahat
Which is more sensitive to changes in GnRH? LH or FSH
LH
What triggers ovulation?
LH surge
What is the predominant hormone during the Follicular phase?
Estradiol
What is the predominant hormone during the luteal phase?
Progesterone
True or False. High levels of FSH exert a negative feedback on GnRH secretion
True
What hormone induces estrogen and progesterone at the level of the ovary by activating aromatase and p450
FSH
What hormones is required for the induction of LH receptors on granulosa cells
FSH
LH
Estradiol
What cells produces progesterone?
Corpus luteum
At what phase of the ovarian cycle is estrogen highest?
end of the follicular phase (directly preovulation)
At what phase of the ovarian cycle is progesterone highest?
5-7 days post ovulation
What are the 2 circulating forms of progesterone?
progesterone
17-hydroxy-progesterone
Which of the following is not a function of prgesterone?
a. stimulate prostaglandin secretion in follicular tissues
b. induction of migration of blood vessel into follicle wall
c. stimulate the release of proteolytic enzymes from thecal cells
d. development of antrum and maturation of graafian follicle
e. none of the above
D. –> estrogen
What are the 2 types of progesterone receptors?
PR-A
PR-B
It acts as an inhibitor of PR-B gene regulation
PR-A
At what phases of the ovarian cycle is PR-A expressed?
Whole ovarian cycle
At what phases of the ovarian cycle is PR-B expressed?
only up to midluteal phase
It is a vasoconstrictor that initiates menstruation
Prostaglandin
What degrades endothelins? In what cells is it localized?
Enkephalinase; endometrial stromal cells
Its activity is in parallel with blood levels of progesterone
Enkephalinase
So it is highest during the midluteal phase and declines when progesterone levels decline
In the absence of fertilization, the corpus luteum becomes what?
corpus albicans
How many days will a corpus luteum last in the absence of fertilization
14 days
What inhibits FSH secretion?
Inhibin B
At what phase/s is estrogen increasing in level?
a. preovulatory phase
b. early luteal phase
c. midluteal phase
d. end of luteal phase
e. A and C
E. A and C
At what phase of the ovarian cycle is LH highest?
10-12 hrs after ovulation
It is the process of development of a graafian follicle into corpus luteum
luteinization
What hormone will be highest in level in implantation occurs?
hCG
What produces hCG?
blastocyst
What happens during day 5 of proliferative phase?
revascularization and epithelial restoration
What events span the proliferative phase of endometrial cycle
follicular phase (from end of menstruation to ovulation)
What events span the secretory phase of endometrial cycle
luteal phase (from ovulation until menstrual phase of next cycle)
Which does NOT happen during proliferative phase
a. proliferation of vascular epithelial, stromal and glandulara stromal cells
b. elongation of endometrial and glands and spiral arteries
c. induction of endometrial glands to secrete glycogen due to progesterone
d. microvilli in epithelial cells
e. C and D
C. happens during secretory phase
It is essential for establishing the changes in blood flow that permit either menstruation or implantation
Spiral artery
This phase of endometrial cycle is highlighted by the growth and dev’t of endometrial spiral artery which arises from the arcuate artery
Secretory Phase
Cytokine that recruits neutrophils to the endometrium prior to onset of menstruation
IL-8
Phase of endometrial cycle where there is infiltration of neutrophils
menstrual phase
Infiltration of neutrophils causes breakdown of what layer
functionalis layer
Phase of endometrial cycle responds to rising levels of progesterone?
secretory phase
inititates matrix degradation
metalloproteinases
Events during menstrual cycle
infiltration of neutrophils metalloproteinases severe coiling of spiral artery resistance to blood flow --> hypoxia, ischemia and degradation of endometrium vasoconstriction
mucosal lining of uterine cavity w/c is shed during menstruation
endometrium
specialized endometrium of pregnancy
Decidua
What is the stimuli for formation of decidua
implanting blastocyst
specialized structure that nourishes the developing fetus
decidua
anatomical site of blatocyst apposition, implantation and placental dev’t
endometrium
a function of hemochorial placentation
decidua
3 parts of decidua
decidua basalis
decidua capsularis
decidua parietalis
3 layers of decidua parietalis + decidua basalis
zona basalis
zona spongiosa
zona compacta
zona spongiosa + zona compacta =
zona functionalis
portion of decidua directly beneath the site of blastocyst implantation
decidua basalis
portion of decidua overlying the enlarging blastocyst
decidua capsularis
found at the periphery and lines the remainder of the uterus
decidua parietalis
avascular, extraembryonic fetal membrane internally connected to decidua capsularis
chorion levae
decidua capsularis + decidua parietalis =
decidua vera
remains after delivery and gives rise to new endometrium
zona basalis
month of pregnancy during which decidua capsularis is most prominent
2nd month
what happens to blood supply of decidua capsularis as the embryo grows
lost
what happens to blood supply of decidua parietalis as the embryo grows
persists (spiral arteries)
what happens to blood supply of decidua basalis as the embryo grows
unresponsive (there is cytotrophoblast invasion which destroys the smooth muscle walls of the spiral arteries and arterioles)
