Test Your Knowledge About Physiology! Trivia Quiz
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A 26-year-old man visits his primary care physician (PCP) complaining of lethargy and muscle weakness. Upon history, the patient also reveals decreased libido, and that he is unable to maintain an erection during intercourse. The PCP suspects this man may have decreased levels of testosterone. Which of the following hormone assays should the PCP order to determine if this man has an impaired hypothalamic-pituitary-testicular axis?
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Testesterone and dihydrotestosterone
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Dihydrotestosterone and prolactin
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Testosterone and follicle stimulating hormone
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Luteinizing hormone and follicle stimulating hormone
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Testosterone and luteinizing hormone
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About This Quiz
The function of the human reproductive system is to produce the components needed for reproduction to take place, and these are the sperm and ova. What do you know about the physiology of the human reproductive system from our previous physiology classes this fall? Take up the quiz below and get to review all we covered and refresh your memory. See moreAll the best!
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- 2.
The Tanner scale (i.e. Tanner Stage) is used by pediatricians to correlate changes in anatomy with the onset of physiological hormone production during puberty. A 13-year-old girl was taken to her pediatrician for a physical exam. This girl was classified as Tanner Stage 2. What are the common physical and physiological characteristics of this young girl?
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Villus hair, basal growth
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Coarse pubic hair, acne
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Projection of aerola, menses
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Breast buds, accelerated growth
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Adrenarche, axillary hair
Correct Answer
A. Breast buds, accelerated growthExplanation
Tanner Stage 2 is typically defined by thelarche, which is the development of breast buds.
Distracter explanations:
1) Adrenarche is a primary characteristic associated with Stage 1.
2) Peak growth occurs during Stage 3.
3) Menarche occurs during Stage 4.
4) Adult features and menstrual cyclicity define Tanner Stage 5.Rate this question:
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- 3.
The majority of a woman's follicles are lost due to atresia. At what age does the greatest rate of atresia usually occur?
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During fetal development
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During peri-menopause while experiencing irregular cyclicity
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During a woman's cyclical years
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During the toddler years
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During puberty before regular cyclicity
Correct Answer
A. During fetal developmentExplanation
Follicular atresia is an ongoing process from fetal development until follicle depletion,
which most often occurs after 40 years of age. Oocyte number peaks at ~7-10 million follicles during
the second trimester (~28 weeks of fetal development), and these numbers then decline rapidly.
Distracter explanations:
1) Rates of atresia are high during toddler years and before puberty - at puberty most women have
~300,000 follicles. However, women have ~7-10 million follicles at ~28 weeks of development, and
therefore `6 million follicles undergo atresia before birth - which is a much greater loss.
2) Approximately 300,000 follicles are lost between puberty and menopause.
3) The majority of follicles are lost before the peri-menopause - and the loss of follicles is the cause of
premature ovarian failure or menopause.Rate this question:
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- 4.
A 39-year-old woman goes to her doctor complaining of irregular menstrual periods. The woman explains that she is experiencing menstrual cycles that range from 21 to 65 days in length. She further complains that she has heavy menstrual bleeding lasting 2 to 3 days during her menstrual period. The patient's BMI is 31; physical exam reveals abnormally large amounts of acne and an unusually high degree of facial hair. Elevations in which of the following hormones is the most likely cause for this patient's symptoms and signs?
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Progesterone
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Testosterone
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Estrone
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Estradiol
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Cortisol
Correct Answer
A. TestosteroneExplanation
This woman is exhibiting a classic presentation of polycystic ovary syndrome (PCOS).
Hyperandrogenemia is one of the diagnostic markers used to diagnose women with PCOS.
Increased amounts of androgen are produced by the theca cells of the follicles - the ovarian cortex
and the adrenal are also sources of increased androgens. Collectively, the excess androgen exerts
phenotypic changes associated with androgen action - many women exhibit hirsutism.
For reasons unknown, the overabundance of ovarian androgen does not cross the basement
membrane and get aromatized into estradiol in the granulosa cells - instead, the majority of this
excess androgen escapes into the systemic circulation. However, some androgen is aromatized to
estradiol in the follicle, and additionally some of the systemic androgen is metabolized to estrone in
the peripheral adipose tissue. Collectively, women with PCOS typically have elevated androgens,
and normal to high-normal levels of estrogen (estradiol PLUS estrone).
Most women with PCOS exhibit anovulatory menstrual cycles, and because most women do
not ovulate this leads to unopposed estrogen acting directly on the endometrium. The effect of this
unopposed estrogen is excessive endometrial proliferation, which eventually causes estrogen
breakthrough bleeding.
Distracter explanations:
1) Progesterone would not cause these effects - this woman likely has very low (or undetectable)
levels of progesterone.
2) Estradiol and Estrone - are likely not elevated. Total estrogen (estrone plus estradiol) may be
elevated. Recognize that it is the unopposed estrogen and lack of progesterone that is most likely
causing the menstrual problems - not the level of estrogen.
3) Cortisol levels may be elevated, may cause irregular cycles, and may cause hirsutism. Cortisol is
a possible answer - but not the best answer.Rate this question:
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- 5.
Theca interna cells and granulosa cells work synergistically to generate ovarian hormones. If a woman is treated with a luteinizing hormone (LH) receptor antagonist during the early proliferative phase of the menstrual cycle, which of the following adverse physiological responses is the most likely outcome?
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Estradiol levels will decline
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Androstenedione levels will increase
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The follicle will undergo atresia and die
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Progesterone levels will increase
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LH levels will decline
Correct Answer
A. Estradiol levels will declineExplanation
This question pertains directly to the 2-cell theory of steroidogenesis. Theca interna cells
express LH receptors and, in response to LH, primarily produce androgens. These androgens then
cross the basement membrane and enter the granulosa cells, where these androgens are then
converted (by the aromatase enzyme) into estrogen ( estradiol and estrone). By blocking the LH
receptor, this pathway will be inhibited and estradiol levels will decline.
Distracter explanations:
1) Progesterone levels will decline - recall that progesterone is an immediate precursor required for
androgen production.
2) Androstenedione is an androgen and will decrease, not increase.
3) LH levels will increase (think about the HPO axis) - but will be unable to act on cells, due on the
receptor antagonist blocking the LH receptor pathway.
4) It is possible that the follicle will undergo atresia and die, but many follicles persist on low levels of
FSH and LH, which is why the proliferative phase can exhibit such extended variations in length.Rate this question:
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- 6.
Which of the following events of fertilization are associated with changes in intracellular calcium?
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Acrosome reaction
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Hyperactivation
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All choices are correct
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Cortical reaction
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Germinal vesicle breakdown
Correct Answer
A. All choices are correctExplanation
All of these events are associated with changes in intracellular calcium, and in some
instances (such as GVBD) the changes in calcium are classic hallmark indicators of the event.
In some events, such as hyperactivation and the acrosome reaction, intracellular changes
occur rapidly and therefore it has been difficult for scientists to determine if the changes in calcium
directly cause the event or are a direct result of the event. Regardless, changes in calcium are
associated with the events occurring.Rate this question:
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- 7.
The gonadotropins, follicle stimulating hormone (FSH) and luteinizing hormone (LH), in large part regulate ovarian function. Elevations in which of the following proteins predominantly inhibits the secretion of FSH?
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Inhibin
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Activin
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Testosterone
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Progesterone
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Chorionic Gonadotropin
Correct Answer
A. InhibinExplanation
Inhibin B produced by the follicles, and Inhibin A produced by the corpus luteum, acts
primarily on the pituitary to suppress the production and secretion of FSH. The placenta
manufacturers and secretes both Inhibin A & B, which suppresses follicle recruitment/growth during
pregnancy.
Remember that Inhibin B produced in granulosa cells inhibits FSH during the proliferative
phase of the cycle. Levels of Inhibin B fall, and levels of Activin increase, during the ovulatory
window - collectively, these changes in Inhibin B and Activin modulate the FSH surge.
Distracter explanations:
1) Evidence(s) suggest hCG acts directly on the hypothalamus to block the production of GnRH,
thereby reducing production of both LH and FSH - but evidence is lacking to suggest hCG acts
directly on the pituitary.
2) Activin stimulates the production and/or release of the gonadotropins.
3) Testosterone and progesterone are not proteins (they are steroids). Both exert negative feedback
on the pituitary and regulate LH secretion - Inhibins/Activin exert greater regulatory control on FSH
secretion.Rate this question:
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- 8.
A 24-year-old man visits his dermatologist. The man is extremely upset because he is suffering from male pattern baldness. The patient explains that none of his older brothers exhibit male pattern baldness. The patient further complains that he was under the assumption that hair growth and baldness were traits inherited through his mother's genes, and he notes his maternal grandfather is 76-years-old and sporting a full head of thick hair. Which of the following hormones is most likely elevated in this patient?
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Testosterone
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Dehydroepiandrosterone (DHEA)
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Androstenedione
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Androstenediol
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Dihydrotestosterone
Correct Answer
A. DihydrotestosteroneExplanation
Testosterone is converted intracellularly by the 5 alpha-reductase (5ARD) enzyme to
dihydrotestosterone (DHT) in the prostate gland, sebaceous glands, hair follicles and testis. Changes
in the localized levels of DHT are associated with adverse prostate function, and elevated levels of
DHT in hair follicles are associated with male pattern baldness.
DHT and testosterone both bind to the androgen receptor. However, DHT exhibits a greater
affinity for the androgen receptor, and therefore DHT is able to exert heightened effects at lower
concentrations.
Distracter explanations:
1) Androstenedione, Androstenediol, and DHEA are weaker androgens, and are not associated with
male pattern baldness.
2) Levels of testosterone may affect circulating levels of DHT - but localized/intracellular
concentrations of DHT are more dependent on the level and activity of 5ARD.Rate this question:
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- 9.
The dominant follicle is a highly vascularized structure that, following ovulation, evolves into a highly vascularized corpus luteum . Which of the following growth factors is most likely involved with the process of luteal angiogenesis?
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Placental growth factor (pGF)
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Insulin growth factor I (IGF1)
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Insulin growth factor II (IGF2)
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Epidermal growth factor (EGF)
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Vascular endothelial growth factor (VEGF)
Correct Answer
A. Vascular endothelial growth factor (VEGF)Explanation
VEGF is an angiogenic growth factor secreted by the follicle just prior to ovulation. VEGF
is required to form the dense capillary bed in the corpus luteum. The dense capillary bed provides
the corpus luteum with a high rate of blood flow, and this high rate of blood flow is second only to the
brain (on a per gram tissue basis). This dense capillary bed also permits for the rapid secretion of
progesterone into the maternal circulation.
Distracter explanations:
1) PGF is also an angiogenic growth factor, but is secreted after formation of the corpus luteum is
complete. PGF acts in concert with VEGF to assist in the vascular remodeling of the uterine vessels
and formation of the placental blood vessels during early pregnancy.
2) The IGFs have no known role in the angiogenic process associated with CL development.
3) EGF acts in concert with VEGF to regulate vascular growth - but is not the best answer.Rate this question:
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- 10.
A 32-year-old woman complains of irregular menstrual cycles. Physical exam reveals galactorrhea; hyperprolactinemia is suspected. Decreased levels in which of the following hormones would confirm this diagnosis?
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Neuropeptide Y
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Nitric Oxide
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Prolactin releasing hormone
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Acetylcholine
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Dopamine
Correct Answer
A. DopamineExplanation
Dopamine is also referred to as "prolactin inhibiting factor". The vast majority of
hormones produced and secreted by the pituitary are stimulated by an associated releasing factor
secreted by the hypothalamus. However, prolactin is under the tonic inhibition by dopamine. As
levels of dopamine fall, the lactotrophs in the pituitary respond rapidly by actively secreting more
prolactin. All of the currently prescribed galatagogues, such as Domperidone, are dopamine
antagonists that act to increase prolactin secretion, resulting in increased breast milk production.
There is some evidence that TRH and a Prolactin Releasing Peptide (PrRP) may stimulate the
secretion of prolactin. However, both of these compounds at physiological levels do not appear
capable of overcoming the tonic inhibition of dopamine. Additionally, TRH stimulation of prolactin
secretion is almost always accompanied by decreased levels of dopamine.
Distracter explanations:
1) NPY - which is released from the arcuate nucleus - may stimulate the release of prolactin, and
therefore levels would not be decreased.
2) Nitric oxide (NO), in normal levels, has been shown in animal models to inhibit prolactin release.
However, there has been no clear consensus on the role (if any) of changes in circulating NO and
changes in prolactin secretion.
3) PRH would increase, not decrease.
4) Acetycholine (Ach) can stimulate oxytocin release - and therefore could stimulate milk letdown.
However, the role of Ach on prolactin is unclear, and therefore this is not the best answer.Rate this question:
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- 11.
A clinical researcher wants to administer a receptor antagonist designed to block growth of the dominant follicle. Inhibition of which receptor would most likely result in suppressed growth and development of the dominant follicle?
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Gonadotropin releasing hormone receptor
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Luteinizing hormone receptor
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Follicle stimulating hormone receptor
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Estrogen receptor
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Progesterone receptor
Correct Answer
A. Gonadotropin releasing hormone receptorExplanation
Blocking the GnRH receptor will result in decreased production of LH and FSH, which will
subsequently inhibit growth of the dominant follicle.
Distracter explanations:
1) You could also suppress follicle growth and development by administering receptor antagonists
designed to inhibit FSH receptor pathway or the LH receptor pathway, but the best answer is a GnRH
antagonist that blocks both LH and FSH activity. Recall the 2-cell theory of steroidogenesis, and how
LH and FSH action on the theca and granulosa cells is a complementary system that results in
estradiol production.
2) Blocking the ER or PR will have variable effects on different systems - and therefore although also
pausible, either of these are not the best answer.Rate this question:
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- 12.
Which of the following hormones is most likely elevated in the follicular fluid of the dominant follicle, but often not measurable in serum, approximately 12 to 36 hours before ovulation?
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Inhibin A
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Inhibin B
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Estradiol
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Progesterone
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Estrone
Correct Answer
A. ProgesteroneExplanation
A rise in intra-ovarian progesterone just prior to ovulation is associated with ovulation and
the subsequent formation of a functional corpus luteum. Cohorts of granulosa cells express a
functional LH receptor prior to ovulation, and during the pre-ovulatory period these cohorts of
granulosa cells bind LH and actively start secreting progesterone into the follicular fluid and systemic
circulation.
This rise in progesterone prior to ovulation, especially as measured in a single blood draw,
may be below the threshold of assay detection in a single serum sample. Measurable increases in
serum progesterone, secreted by the newly formed corpus luteum, are detectable (above baseline)
typically within 24-hrs following ovulation, (and most of the time much sooner, within 6 -12 hrs).
Further, increases in progesterone above baseline are always indicative of a successful ovulation and
associated with the formation of a corpus luteum.
Distracter explanations:
1) Estradiol and estrone levels rise in pre-ovulatory follicles, but that high intraovarian estrogen levels
typically persist for 48 to 96 hours prior to ovulation. Estrogen is measurable throughout the entire
menstrual cycle, with concentrations highest just before ovulation.
2) Inhibin B levels fall during the pre-ovulatory period, and coupled with a rise in Activin, stimulate the
FSH surge associated with ovulation.
3) Inhibin A is produced predominantly by the corpus luteum - levels of Inhibin A do not typically rise
until AFTER ovulation.Rate this question:
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- 13.
A 28-year-old woman visits the gynecologist complaining of irregular menstrual cycles that persist for 45-60 days. Physical and pelvic exams are unremarkable. The gynecologist wants the woman to experience a normal menstrual cycle of 28 to 30 days. The woman agrees to participate in a clinical trial and is subsequently given an orally-active compound that is designed to release high levels of hCG over a 24 hour period. If day 1 is the first day of visible menses, on which day of the menstrual cycle is this woman instructed to take this compound to achieve her gynecologist's ideal menstrual cycle length?
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Day 10
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Day 12
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Day 15
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Day 18
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Day 20
Correct Answer
A. Day 15Explanation
You recognized that LH and hCG exhibit a high degree of homology and both bind with
high affinity to the LH receptor. In a typical menstrual cycle, the peak of the LH surge occurs
approximately 10-12 hours before ovulation, which is considered the same day as ovulation (i.e.
within a 24 hr period). An acute release of hCG would mimic the LH surge, resulting in ovulation of
the dominant follicle.
You also remembered that the corpus luteum has a finite lifespan of 12-16 days, and therefore
to induce a 28 to 30 day menstrual cycle, ovulation must occur approximately 12-16 days before
menses. Thus, of the choices offered the optimal day to induce ovulation is Day 15, since this will
result in elevated progesterone for approximately 12-16 days resulting in a menstrual cycle length of
27-31 days.
Distracter explanations:
1) Day 10 would result in a likely 22 to 26 day cycle, which is a short cycle.
2) Day 20 would result in a cycle longer than 30 days.
3) Day 12 or Day 18 are possible choices. Giving the pill on day 12 could result in a menstrual cycle
of 24 to 28 days, and giving the pill on day 18 would likely result in a cycle length of 30-34 days.
However, the best choice is day 15, which covers the entire tight 3 day range (i.e. total length of 28 to
30 days).Rate this question:
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- 14.
Which of the following accurately describe the chronological set of descriptive changes that occur in the endometrium during the menstrual cycle?
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Proliferation, secretion, decidualization, menstruation
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Decidualization, menstruation, secretion, proliferation
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Menstruation, secretion, decidualization, proliferation
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Menstruation, decidualization, proliferation, secretion
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Secretion, menstruation, proliferation, decidualization
Correct Answer
A. Proliferation, secretion, decidualization, menstruationExplanation
The endometrium expresses estrogen and progesterone receptors, and therefore the
ovarian hormones directly influence endometrial changes. The endometrium proliferates rapidly
under the influence of estradiol, and therefore this is termed the "proliferative phase". Progesterone
induces glandular sacculation and stimulates the production of secretory compounds, and therefore
this phase is termed the "secretory phase". Extended exposure to progesterone, for 10 days or
longer, causes the endometrial stromal cells to undergo the decidual response (i.e. "decidualization").
In a normal menstrual cycle, the corpus luteum stops secreting progesterone after 12-16 days, and
the subsequent progesterone withdrawal induces sloughing of the endometrial functionalis zone
during "menstruation".
Regardless of which phase you list first, the sequence of events is always constant (i.e. proliferation
always precedes secretion, which always precedes decidualization, etc.).Rate this question:
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- 15.
A 33-year-old woman on a progesterone-only intrauterine system (IUS) method of birth control visits her gynecologist. The patient explains that she wants to start a family. The IUS is removed and the patient charts 3 normal menstrual cycles of exactly 29 days before trying to get pregnant. The woman and her husband engage in daily intercourse for the next 8 months, but she does not get pregnant. The majority of menstrual cycles lasted 29-30 days, except for one lone menstrual cycle that lasted 45 days. The patient returns to the gynecologist, concerned about the lone menstrual cycle that lasted 45 days. Which of the following conditions is the most likely cause of this woman's concerns?
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An extended secretory phase of the menstrual cycle
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Elevated levels of estradiol during the secretory phase
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An extended proliferative phase of the menstrual cycle
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Elevated levels of progesterone during the secretory phase
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A spontaneous abortion
Correct Answer
A. A spontaneous abortionExplanation
It is estimated that 50% of all zygotes are lost to spontaneous abortion before
implantation, and that another 20-30% of all pregnancies are lost during the implantation process.
Thus, the slightly extended menstrual cycle is most likely due to a spontaneous abortion during very
early pregnancy.
Distracter explanations:
1) The secretory phase is 12-16 days, because the corpus luteum has a finite lifespan of 12-16 days
in a non-pregnant cycle. Extending the secretory phase indicates the woman was pregnant - but this
is not the best answer.
2) There is no evidence to suggest that elevated levels of estradiol during the secretory phase affect
menstrual cycle length.
3) Elevated levels of progesterone would not extend the phase - in actuality, very high levels of
progesterone of the secretory phase have been correlated (in some studies) with heavy menstrual
bleeding.
4) An extended proliferative phase, which is the primary cause for variations in the menstrual cycle
(remember the secretory/luteal phase is 12-16 days and dependent on the lifespan of the CL), is a
possible answer. However, because this woman experienced 10/11 menstrual cycles of exactly 29
days (3 prior to trying to get pregnant and 7/8 while trying), this suggests her proliferative phase is
tightly controlled. This woman was having unprotected intercourse for 8 months, and therefore the
lone deviation in menstrual cycle length in this woman's specific situation is more likely due to a
spontaneous abortion than a result of an extended proliferative phase.Rate this question:
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- 16.
A 29-year-old man visits his urologist for a vasectomy. The patient explains that he is sexually active with multiple partners and does not want to father a child. Following the procedure, how long should the man abstain from intercourse to ensure he does not become a father?
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1-2 weeks
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3-4 weeks
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4-6 weeks
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6-10 weeks
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10-15 weeks
Correct Answer
A. 4-6 weeksExplanation
Mature sperm survive in the epididymis for approximately 4 to 6 weeks before being
ejaculated or being catabolized and resorbed. A man is informed that he can father a child for up to 6
weeks following a vasectomy. Most urologists and or vasectomy clinics will test a man's sperm count
after 20 ejaculations or 6 weeks following a vasectomy.
Sperm are able to survive for this extended duration due to the lower temperatures within the scrotum.
In the female reproductive tract, most sperm die within 24-48 after ejaculation - however, some
studies have shown that viable sperm can be recovered 5 days after a single ejaculation during
intercourse.Rate this question:
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- 17.
A 39-year-old woman visits her gynecologist. The patient explains that her husband wants children; she explains that she is scared about starting a family this late in life because she knows the quality of her oocytes is decreasing at a rapid rate. Which of the following biological processes explains the primary cause of the woman's fear?
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Folliculogenesis
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Ovulation
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Fertilization
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Oogenesis
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Atresia
Correct Answer
A. AtresiaExplanation
Atresia is the process by which follicles/oocytes are depleted from the ovarian pool. The
highest rate of atresia occurs during fetal development, and continues throughout a woman's lifespan
until menopause, which signals complete follicle depletion.
Distracter explanations:
1) One could argue that atresia is a part of folliculogenesis, but we typically think of the two processes
separately. The processes are considered separately because the primary outcome of
folliculogenesis is the selection and ovulation of a dominant follicle, whereas the outcome of atresia is
follicle death, regardless of follicle stage (i.e. preantral and antral follicles undergo atresia).
2) Ovulation is the temporospatial and hormonally-regulated release of the ovum from the follicle.
The ovulatory process has not been correlated with oocyte quality.
3) Fertilization is the union of an egg with sperm - this does not have any effect on egg quality.
However - it has been argued for ages that only high-quality oocytes can get fertilized by semen.
4) Oogenesis is the development of ova - which occurs during fetal development.Rate this question:
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- 18.
A 33-year-old woman tests positive on a home-pregnancy kit. She visits her gynecologist, and urinalysis is positive for chorionic gonadotropin. Sonograms reveal a fetal crown-rump length consistent with 8 weeks' of pregnancy. Which of the following physiological events is specific to this time point in this patient's pregnancy?
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Blastocyst invasion
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Formation of the placenta
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Spiral artery remodeling
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Luteal-placental shift
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Syncytiotrophoblast hCG production
Correct Answer
A. Luteal-placental shiftExplanation
The luteal-placental shift occurs between 7-9 weeks of gestation. A fully functional
placenta begins secreting hormones, including estriol, during the luteal-placental shift. A rise in
estriol, the estrogen of pregnancy, indicates that the maternal-fetal-placental unit is fully functional.
Distracter explanations:
1) Blastocyst invasion and formation of the placenta are complete by the end of the first month of
gestation.
2) Spiral artery remodeling and hCG production are ongoing events during the first trimester, but
these events are not specific to 8 weeks of gestation.
3) hCG levels start to decline during/after the luteal-placenta shift - the placenta starts producing the
large amounts of progesterone necessary to maintain pregnancy, and these high levels of placental
progesterone are thought to suppress the production of placental hCG.Rate this question:
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- 19.
Human chorionic gonadotropin (hCG) rescues the corpus luteum during early pregnancy by acting directly on the granulosa-lutein cells. Which of the following statements best describes the primary functions of the granulosa-lutein cells (GLC) and theca-lutein cells (TLC) during early pregnancy?
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GLC secrete estrogen and progesterone; TLC secrete androgen and estrogen
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GLC secrete androgen and estrogen; TLC secrete progesterone and estrogen
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GLC secrete progesterone and androgen; TLC secrete progesterone and androgen
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GLC secrete progesterone and androgen; TLC secrete androgen and estrogen
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GLC secrete estrogen and progesterone; TLC secrete androgen and progesterone
Correct Answer
A. GLC secrete estrogen and progesterone; TLC secrete androgen and progesteroneExplanation
Granulosa-lutein cells (GLC) and theca-lutein cells (TLC) both express functional LH
receptors, and the GLC secrete progesterone and estrogen whereas the TLC secrete androgen
(predominantly androstenedione) and progesterone. The GLC then aromatize the androgen into
estrogen. These cells types can also be distinguished histologically, since the TLC express high
levels of CYP17 (the enzyme required to convert progesterone into androgen) whereas the GLC
express CYP19 (aromatase, required to convert androgen into estrogen).
Remember that the primary function of the CL is to secrete progesterone.
Steroidogenesis Summary:
Granulosa cells = estrogen during the follicular phase
Granulosa cells = estrogens and progesterone during the pre-ovulatory window (after they acquire the
LH receptor)
Granulosa-lutein cells = progesterone and estrogen during the luteal phase
Theca cells = androgens
Theca-lutein cells = androgens and subsidiary amounts of progesterone
hCG = binds to the LH receptor and therefore maintains luteal steroidogenesis resulting in continued
progesterone production
The CL predominantly secretes progesterone. Follicles predominantly secrete estrogen.Rate this question:
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- 20.
A 57-year-old man visits his urologist complaining of the sudden onset of a sexually-related concern. The patient explains that he and his wife enjoy intercourse 3 to 4 times each week, but within the past 2 weeks he has been unable to ejaculate, yet mentally feels like he has achieved an orgasm. The patient further explains that he has had no difficulty in becoming aroused, he has always achieved a full erection, and has experienced no difficulties maintaining an erection during intercourse. The patient denies taking any erectile dysfunction drugs (e.g. Viagara). Physical exam is unremarkable; lab results reveal normal levels of testosterone and luteinizing hormone. Which of the following is the most likely cause of this patient's symptoms and signs?
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Impaired release of nitric oxide
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Lack of emission
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Impaired penile nervous system resulting in lack of ejaculatory stimuli
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The patient is depressed and failure to ejaculate is a psychological problem
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Reduced blood flow to the corpus cavernosa
Correct Answer
A. Lack of emissionExplanation
This man is suffering from a condition termed anejaculation. This man is experiencing a
problem with the ejaculatory process and you recognized that emission is the transport of semen from
the testis into the urethra.
Distracter explanations:
1) History reveals this patient is exhibiting no difficulties in achieving an erection, and therefore this
suggests that he has a sufficient release of nitric oxide and adequate blood flow to the penis.
2) He has no problems with arousal or erection, therefore there is most likely no problems with his
penile nervous system.
3) This man may be depressed, but men experiencing psychological sexual problems typically
experience erectile dysfunction or do not experience an emotional "orgasm".Rate this question:
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- 21.
Flutamide is an androgen receptor antagonist. Flutamide has been tested in nonhuman primates as a contraceptive, and markedly suppressed stromal expansion of the endometrial functionalis zone, which resulted in high rates of infertility in female rhesus macaques. Which of the following physiological processes was most likely affected by this compound?
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Gamete transport
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Menstruation
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Decidualization
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Fertilization
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Implantation
Correct Answer
A. ImplantationExplanation
An adequate functionalis layer is required to support an invading blastocyst during the
process of implantation. In women experiencing infertility, ultrasound is often used to measure
endometrial thickness - progesterone supplementation may be prescribed to those women exhibiting
an abnormally thin endometrium. Remember that implantation requires progestational differentiation
of the endometrium - progesterone induces sacculation of the endometrial glands, stimulates
epithelial cell secretion, stromal cell expansion and hypertrophy of the spiral arteries.
Distracter explanations:
1) The processes of decidualization and menstruation will occur in a normal manner, there will just be
less tissue to undergo differentiation and enzymatic breakdown during those processes, respectively.
2) An underdeveloped endometrium is not capable of supporting implantation, but to date there is no
evidence to suggest an inadequate functionalis zone will inhibit gamete transport or subsequent
fertilization of an egg and sperm.Rate this question:
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- 22.
Acquisition of the LH receptor by the granulosa cells is absolutely necessary for ovulation of the dominant follicle. Which of the following compounds is secreted by the granulosa cells in response to LH stimulation?
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Estradiol
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Fibronectin
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Serine proteases
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Matrix metalloproteinases
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Androstenedione
Correct Answer
A. Matrix metalloproteinasesExplanation
Cohorts of granulosa cells begin expressing functional LH receptors prior to ovulation,
and these cells then respond to LH by secreting progesterone. LH also acts to stimulate the
increased production of prostaglandins and the matrix metalloproteinases (MMPs), two components
that are required for the temporospatial breakdown of the follicular wall.
Distracter explanations:
1) Estradiol is produced by the granulosa cells in response to FSH - not LH. The granulosa-lutein
cells (of the CL) secrete estrogens in response to LH - but the granulosa cells of the dominant follicle
still require FSH stimulation.
2) Androstenedione is secreted by the theca cells, not granulosa cells.
3) Serine proteases are released by the granulosa cells during ovulation, but this is an FSH mediated
event.
4) Fibronectin is a component of the basal lamina of ovarian follicles. Levels of fibronectin do not
increase due to the effects of LH - levels of fibronectin increase as a result of MMP degradation.Rate this question:
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- 23.
The process of fertilization is a complex set of temporospatially coordinated interactive events between male and female gametes. The adequate transportation of both sperm and oocyte in the female reproductive tract is critical for fertilization. Which physiological change occurs during the ovulatory window that enhances gamete transport in the female reproductive tract?
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Thinning of the cervical mucus
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Decreased vaginal secretions
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Increased uterine blood flow
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Decreased uterine contractility
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Decidualization of the endometrial stroma
Correct Answer
A. Thinning of the cervical mucusExplanation
Thinning of the cervical mucus, coupled with increased vaginal secretions during
intercourse, enhance sperm transport through the lower portion of the female reproductive tract.
Ferning of cervical mucus on a glass slide is indicative of a receptive cervix, and cervical mucus
typically exhibits ferning for approximately 10 days of the menstrual cycle (if menses is day 1, then
~day 5 to day 17). Slight contractility of the uterus aids in sperm transport through the endometrial
lumen. Cilia beat frequency becomes rhythmical and secretions increase in the fallopian tube, which
enhances both sperm and oocyte transport.
Distracter explanations:
Decreased vaginal secretions, increased uterine blood flow, decidualization of the endometrial stroma
and decreased uterine contractility are all effects induced by progesterone during the secretory phase
of the menstrual cycle, and are not associated with ovulation.Rate this question:
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- 24.
A 32-year-old woman, gravida 2, para 1, is 32 weeks' pregnant. Lab results reveal normal levels of estriol. What is the most likely physiological activity of this hormone?
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Stimulates blastocyst invasion
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Stimulates vascular remodeling of the spiral arteries
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Stimulates the secretion of luteal progesterone
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Stimulates endometrial decidualization
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Stimulates vasodilation and uterine blood flow
Correct Answer
A. Stimulates vasodilation and uterine blood flowExplanation
All three estrogens are secreted in large amounts and (estrone, estradiol, estriol) act as
vasodilators to increase blood flow to the uterus and growing placenta. Estriol is synthesized by the
fully functional placenta after the luteal-placental steroidogenic shift, and is considered the estrogen
of pregnancy.
Remember that you can associate each estrogen with significant events in a woman's reproductive
years:
Estrone (E1): Estrogen of menopause; increased due to peripheral metabolism of androgens
to estrone (especially in adipose tissues).
Estradiol (E2): Estrogen of reproductive years and primary estrogen produced during the
menstrual cycle; associated with follicle growth & development and reproductive tract changes
during the proliferative phase of the menstrual cycle.
Estriol (E3): Estrogen of pregnancy; produced by the placenta.
Also remember that all three estrogens bind to the same nuclear estrogen receptors (ER). The order
of binding affinity/specificity is as follows: E2 > E1 > E3
E2 binding affinity to the ER is 5 to 10-fold greater than E1, and E2 binding affinity to the ER is
at least 20-fold (and likely 100-fold or more) greater than E3.
Distracter explanations:
1) Estrogens are not associated with blastocyst invasion.
2) Progesterone, not estrogen, stimulates hypertrophy of the spiral arteries.
3) LH and hCG stimulate luteal progesterone production - the role of estrogen is unclear.
4) Exposure to progesterone for ~10 days stimulates decidualization of the endometrial stromal cells -
the endometrial epithelia do not decidualize.Rate this question:
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- 25.
A 44-year-old married woman, and her husband of 20 years, visit the gynecologist for a menstrual complaint. The patient has not experienced a menstrual period for 3 months and further complains of minor nausea for the past week, which she attributes to a "bug going around". During history, the woman states that she is "deathly afraid" that she has entered menopause - her husband and her are considering another child, and her three older sisters all experienced horrible symptoms when they transitioned through menopause at 46, 49, and 54 years of age. Which of the following hormones is most likely elevated in this patient and the cause of her nausea and amenorrhea?
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Human chorionic gonadotropin
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Progesterone
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Follicle stimulating hormone
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Gonadotropin releasing hormone
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Estrone
Correct Answer
A. Human chorionic gonadotropinExplanation
This woman's history and age suggest early menopause is possible (two of her sisters
experienced menopause before age 50), but nausea is not a typical symptom associated with
menopause. The history of no menstrual period for 3 months and onset of nausea is indicative of
pregnancy, likely near the beginning of the 2nd trimester. An hCG test will quickly determine
pregnancy status.
Distracter explanations:
1) Measuring progesterone will help determine if the patient is ovulating - but elevated progesterone
is not associated with nausea or amenorrhea.
2) Elevated levels of FSH and estrone are associated with depletion of the ovarian follicles, and are
markers for premature ovarian failure and menopause. However, nausea is not a symptom typically
associated with menopause - therefore, measuring hCG and determining pregnancy status is the first
(and easiest) hormone assay. IF the pregnancy test is negative, then measuring the levels of FSH
would be the next best answer.
3) GnRH is released into the portal system, and therefore GnRH can not be measured in women.
The relative levels of GnRH are estimated based on the levels of FSH and LH.Rate this question:
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Current Version
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Oct 28, 2024Quiz Edited by
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Nov 09, 2012Quiz Created by
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