ovarian and uterine cycle Flashcards
Why is the ovary considered an endocrine gland?
A. It produces oocytes and maintains the uterine lining
B. It secretes estrogen and progesterone directly into ducts
C. It releases hormones that regulate secondary sex characteristics and the menstrual cycle
D. It controls uterine contractions via oxytocin
The ovary is an endocrine gland because it secretes hormones (estrogen and progesterone) directly into the bloodstream, which regulate secondary sexual characteristics and the menstrual cycle, not via ducts like exocrine glands
. Option B is incorrect because endocrine secretion is into blood, not ducts.
Which of the following best describes a similarity between oogenesis and spermatogenesis?
A. Both processes are continuous throughout life
B. Both processes begin at puberty
C. Both produce four functional gametes from each precursor cell
D. Both involve meiosis and hormonal regulation
Both oogenesis and spermatogenesis involve meiosis and hormonal control, such as FSH and LH. However, oogenesis begins before birth and completes later, while spermatogenesis starts at puberty and continues through life, making D the only universally true statement
What is the key hormonal event that triggers ovulation?
A. Steady increase in FSH during early follicular phase
B. Sudden drop in progesterone in late luteal phase
C. Estrogen-mediated positive feedback causing LH surge
D. Gradual rise in inhibin leading to follicular rupture
A sustained high level of estrogen during the late follicular phase causes a positive feedback loop on the hypothalamus and anterior pituitary, resulting in the LH surge, which is the immediate trigger for ovulation
. This is a reversal from the usual negative feedback effect of estrogen.
Know that estrogen stimulates LH secretion
Which of the following best defines the LH surge and its timing?
A. A sudden rise in LH after ovulation due to falling estrogen
B. A brief peak in LH triggered by progesterone mid-luteal phase
C. A spike in LH on day 14 due to positive feedback by estrogen
D. A sustained LH elevation during the secretory phase
A spike in LH on day 14 due to positive feedback by estrogen
This surge induces ovulation
. The other options misstate the cause or timing.
Which statement accurately describes the menstrual cycle in relation to hormone levels and uterine changes?
A. Progesterone peaks during the proliferative phase, causing thickening of endometrium
B. Menstruation begins when estrogen and progesterone levels rise
C. Estrogen promotes endometrial growth in the follicular phase; progesterone maintains it in the luteal phase
D. LH and FSH are highest during the secretory phase to support uterine receptivity
: During the follicular (proliferative) phase, estrogen stimulates endometrial growth; in the luteal (secretory) phase, progesterone (along with estrogen) maintains and modifies the lining for potential implantation
. Menstruation occurs when both hormone levels drop.
c
Which best describes the levels of estrogen and progesterone around Day 14 and Day 28 of the menstrual cycle?
A. Estrogen and progesterone are both low at Day 14 and rise sharply by Day 28
B. Estrogen peaks near Day 14, while progesterone peaks after ovulation and drops near Day 28 if no pregnancy occurs
C. Progesterone is highest at Day 14, initiating the LH surge, and estrogen remains low until menstruation
D. Both hormones are highest at Day 28 to maintain endometrial stability and suppress FSH/LH
Around Day 14, estrogen peaks, triggering the LH surge and ovulation. After ovulation, the corpus luteum forms, secreting high progesterone during the luteal phase (peaking around Day 21). If there’s no pregnancy, both hormones drop sharply near Day 28, triggering menstruation
. Option D is incorrect because hormone levels fall at Day 28, not rise.
positive feedback of estrogen around day 14, causes more LH anf FSH
What is the correct pattern of FSH and LH secretion near Day 14 and Day 28 of the menstrual cycle?
A. Both LH and FSH surge at Day 14 due to high progesterone, and stay elevated through Day 28
B. FSH and LH are low at Day 14 due to negative feedback from estrogen, and rise again near Day 28
C. LH surges sharply at Day 14 due to high estrogen, while FSH has a minor rise; both are suppressed by Day 28 due to progesterone
D. LH and FSH show twin peaks at Day 28 to stimulate follicular growth for the next cycle
High estrogen near Day 14 causes a positive feedback loop leading to a large LH surge and a smaller FSH increase, which trigger ovulation. By Day 28, progesterone from the corpus luteum exerts negative feedback on the hypothalamus, suppressing FSH and LH levels. If no pregnancy occurs, the hormone levels drop, initiating the next cycle
FSH and LH starts to slowly rise up again on day 28
. Option D is incorrect; LH and FSH only rise after hormone levels fall and menstruation begins—not at Day 28.
Why do estrogen levels decrease after Day 14 of the menstrual cycle, only to rise again during the luteal phase?
A. The dominant follicle ruptures at ovulation, halting its estrogen production; estrogen then rises again due to LH-induced granulosa cell proliferation
B. Estrogen levels fall after ovulation because inhibin suppresses estrogen production; they rise again from increased GnRH secretion
C. Estrogen is no longer needed after Day 14, but small amounts continue to be secreted by the corpus luteum to stimulate FSH
D. Estrogen declines after the LH surge but increases again as the corpus luteum begins secreting estrogen and progesterone
Estrogen levels drop immediately after ovulation (Day 14) because the dominant follicle ruptures, ending its estrogen output. However, the newly formed corpus luteum then starts producing both progesterone and some estrogen, causing a secondary rise in estrogen during the luteal phase
. Option A is partly right but doesn’t mention the corpus luteum, which is crucial. Option B misattributes the fall to inhibin, which mainly regulates FSH, not estrogen.
What is the effect of inhibin on FSH secretion during the follicular phase?
A. Inhibin promotes FSH release by sensitizing granulosa cells
B. Inhibin blocks LH secretion to prevent early ovulation
C. Inhibin suppresses FSH secretion via negative feedback from the dominant follicle
D. Inhibin triggers the LH surge through its action on GnRH neurons
Inhibin is secreted by granulosa cells of the dominant follicle and acts via negative feedback on the anterior pituitary to suppress FSH secretion. This helps ensure that only one dominant follicle continues to develop, while others undergo atresia
. It has no direct effect on LH or GnRH.
What does a rise in LH and FSH around Day 28 of the cycle typically indicate?
A. Ovulation is about to occur
B. Corpus luteum is strengthening to support implantation
C. Hormonal feedback has ceased due to corpus luteum degeneration, signaling the start of a new cycle
D. Estrogen levels are peaking again, preparing for a second LH surge
By Day 28, the corpus luteum degenerates if no pregnancy has occurred, causing a drop in estrogen and progesterone. This removes the negative feedback, leading to a rise in LH and FSH, which marks the end of the current cycle and the beginning of a new one
. Option A is incorrect—ovulation occurred two weeks earlier.
Why is there a small increase in progesterone around Day 14 of the menstrual cycle?
A. The ruptured follicle begins forming the corpus luteum, which starts secreting progesterone
B. The LH surge directly stimulates progesterone secretion by the uterine lining
C. Progesterone is released by the dominant follicle to trigger the LH surge
D. Estrogen levels fall, so the anterior pituitary compensates by releasing progesterone
Just after ovulation (around Day 14), the ruptured follicle transforms into the corpus luteum, which begins secreting small amounts of progesterone. This modest increase marks the early luteal phase and prepares the uterus for potential implantation
. The full rise in progesterone follows shortly after. Option C is incorrect—estrogen, not progesterone, triggers the LH surge.
_____ is dominant during day-day14 of the menstrual cycle, while ______ is dominant during day 14-28
estrogen, progesteronew
why is the LH surge on day 14 so important?
it allows the release of the mature oocyte into the ovary
how does the estrogen cause positive or negative feedback after the menstraul cycle, before ovulation, and when estrogen increases during the luteal phase
after mentrual cycle: low estrogen causes negative feedback of LH and FSH, keeping their levels constant prior to ovulation
near ovulation: estrogen peak causes positive feedbakc of LH and FSH
estrogen increase during the luteal phase causes negative feedback, lowering FSH and LH
During the proliferative phase of the menstrual cycle, which of the following best describes the effect of estrogen on the uterus and cervix?
A. Estrogen causes endometrial shedding and stimulates secretion of thick, sticky cervical mucus to block sperm
B. Estrogen promotes endometrial regeneration and induces cervical glands to secrete thin, watery, sperm-friendly mucus
C. Estrogen inhibits endometrial growth while increasing progesterone levels and forming a cervical mucus plug
D. Estrogen suppresses uterine blood flow and causes cervical glands to become inactive
Estrogen promotes endometrial regeneration and induces cervical glands to secrete thin, watery, sperm-friendly mucus
Which of the following best describes what occurs during the secretory phase of the menstrual cycle?
A. Estrogen triggers rapid endometrial shedding and cervical plug formation
B. LH and FSH stimulate uterine contractions and thin mucus secretion
C. Progesterone maintains the endometrial lining, promotes glandular secretions, and thickens cervical mucus to form a plug
D. The corpus luteum degenerates, leading to immediate menstruation and ovulation
The secretory phase occurs after ovulation and is driven primarily by progesterone, which:
Maintains and modifies the endometrial lining, making it receptive to implantation
Stimulates glandular secretions rich in glycogen (nutrients for potential embryo)
Causes cervical mucus to become thick and sticky, forming a plug that prevents further sperm entry
All of these are classic features of the luteal phase/secretory phase, as described on Slide 34
.
Which statement best summarizes the key differences between estrogen and progesterone based on their target effects?
A. Estrogen and progesterone both cause uterine contractility and make cervical mucus sperm-friendly
B. Estrogen promotes growth and proliferation; progesterone stabilizes and suppresses excess stimulation
C. Estrogen is only active in the ovary, while progesterone primarily affects the brain and cervix
D. Estrogen suppresses follicular growth while progesterone promotes ovulation
As shown on Slide 35, estrogen is the “builder”:
Promotes growth of endometrium, myometrium, and breast ducts
Increases contractility, blood flow, and oxytocin sensitivity
Meanwhile, progesterone acts to stabilize:
Reduces contractility, seals the cervix with viscous mucus, and promotes endometrial secretions
Calms uterine activity—”progesterone keeps everything calm”
