Physiology III: Female Reproduction
90% of all US girls are menstruating by what age?
13.75 years
Aromatase converts testosterone to what?
17beta-estradiol
Typically, menses lasts how many days?
4 to 5 days
What is the name given to onset of a young woman's first menstrual period? A) Menarche B) Menses C) Eclampsia D) Amenorrhea
A) Menarche
Which hormone only has a biological function in women? A) Prolactin B) Thyroid-stimulating hormone C) Follicle stimulating hormone D) Luteinizing hormone
A) Prolactin
Once conception takes place, which of the following must occur for the pregnancy to proceed in a healthy manner? A) The corpus luteum must secrete progesterone to sustain the endometrium B) The pituitary must secrete HCG to maintain the corpus luteum C) The placenta must secrete FSH to maintain ovarian function D) The placenta must secrete LH to maintain ovarian function
A) The corpus luteum must secrete progesterone to sustain the endometrium
In pregnancy, estriol is the major estrogen. The formation of estriol during pregnancy requires assistance from the fetus. Which of the following describes the role of the fetus in the synthesis of estriol during pregnancy? A) The fetal liver provides 16-OH-DHEA-sulfate to the placenta to be converted into estriol B) The fetal adrenal gland provides pregnenolone to the placenta to be converted into estriol C) The fetal adrenal gland provides aromatase to the placenta to be converted into estriol D) The fetal liver provides pregnenolone to the placenta to be converted into estriol
A) The fetal liver provides 16-OH-DHEA-sulfate to the placenta to be converted into estriol
What enzyme converts androstenedione to estrogen (17β-estradiol)?
Aromatase
The hypothalamus becomes less sensitive to the suppressing effect of estrogen during what?
As puberty approaches
With respect to hormonal changes during pregnancy, which of the following is a source of estrogen and progesterone during the first 2 months of pregnancy? A) Anterior pituitary B) Corpus luteum C) Ovary D) Placenta
B) Corpus luteum
Assuming a regular menstrual cycle of 28 to 30 days, ovulation would be expected to occur between: A) Days 6 and 8 B) Days 14 and 16 C) Days 18 and 20 D) Days 22 and 24
B) Days 14 and 16
Biological actions of estrogens include: A) Inhibition of follicular growth B) Delayed bone loss C) Increased glucose tolerance D) Decreased serum LDL cholesterol
B) Delayed bone loss
During pregnancy, the fetus plays a role in the formation of maternal steroid: A) Testosterone B) Estriol C) Progesterone D) Dehydroepiandosterone sulfate
B) Estriol
The hormone primarily responsible for development of ovarian follicles prior to ovulation is? A) Chorionic gonadotropin B) Follicle-stimulating hormone (FSH) C) Luteinizing hormone D) Progesterone
B) Follicle-stimulating hormone (FSH)
Which one of the following is true about the luteal phase of the menstrual cycle? A) It occurs as the uterine epithelium regrows under the stimulation of estrogens B) It begins at ovulation and continues while the corpus lute is intact C) It refers to the release of progesterone by the corpus luteum D) During this phase the follicle develops prior to ovulation
B) It begins at ovulation and continues while the corpus lute is intact
Which one of the following effects does luteinizing hormone produce? A) It stimulates the growth of a few follicles each month B) It stimulates ovulation and maintains the corpus luteum C) It prepares the uterus for pregnancy D) It establishes and maintains the secondary sex characteristics
B) It stimulates ovulation and maintains the corpus luteum
Which of the following hormones is involved in the ejection of milk from a lactating mammary gland? A) Estrogen B) Oxytocin C) Progesterone D) Prolactin
B) Oxytocin
What is the hormone responsible for breast milk production? A) Estradiol B) Prolactin C) Oxytocin D) Progesterone
B) Prolactin
Which of the following is true regarding prolactin? A) Prolactin causes milk ejection during suckling B) Prolactin inhibits GnRH secretion by the hypothalamus C) Prolactin inhibits gonadotropin secretion by the pituitary gland D) Prolactin inhibits growth of breast tissue
B) Prolactin inhibits GnRH secretion by the hypothalamus
Which one of the following statement is FALSE? A) Before the fertilized ovum reaches the uterus, the mucous membrane of the uterus undergoes important changes forming specialized tissue known as the decidua. B) The endometrium differentiates into a specialized layer of decimal cells under the influence of estrogen C) The decidua is a thick layer of modified mucous membrane that lines the uterus D) Decidua contributes the maternal portion of the placenta
B) The endometrium differentiates into a specialized layer of decimal cells under the influence of estrogen
The hypothalamus is extremely sensitive to the suppressing effect of the very low levels of circulating estrogen during what?
Before puberty
Thecal cells produce...? A) Mucus B) Luteinizing hormone C) Androgen D) Estradiol
C) Androgen
Oxytocin is responsible for: A) Preventing milk release from mammary glands B) Production of breast milk in the mammary glands C) Causing contraction of the uterus during labor D) Maintaining normal calcium levels
C) Causing contraction of the uterus during labor
As the time of delivery of a newborn draws near, the fetal hypothalamic-pituitary-adrenal axis increases production of cortisol. The cortisol induces several physiological changes in the fetus to ensure survival outside of the womb. Which of the following is NOT a physiological change induced by fetal cortisol? A) Increased production of thyroid hormone B) Increased glycogen storage and gluconeogenesis in the fetal liver C) Increased synthesis of pregnenolone by the fetal liver D) Structural maturity of the lung tissue
C) Increased synthesis of pregnenolone by the fetal liver
What term is applied to the final two weeks of the menstrual (uterine) cycle? A) Menses B) Follicular phase C) Luteal phase D) Ovulation
C) Luteal phase
What is the function of progesterone? A) To stimulate the development of follicles B) To maintain the corpus luteum C) Prepare and maintain the uterus for pregnancy D) To stimulate ovulation
C) Prepare and maintain the uterus for pregnancy
Regarding a normal menstrual cycle, where is the hormone progesterone produced? A) Progesterone is produced by the thecae cells that surround the follicle B) Progesterone is produced by the anterior pituitary C) Progesterone is produced by the corpus luteum D) Progesterone is produced by the developing follicle
C) Progesterone is produced by the corpus luteum
LH stimulates what enzyme in the theca cells?
Cholesterol desmolase
During ovulation, a mature ova is released from a dominant follicle. Following the release of the ova the follicle seals itself off and forms what is known as..
Corpus luteum
Anatomically, where does fertilization normally take place? A) Uterus B) Cervix C) Ovary D) Ampulla of the fallopian tubes
D) Ampulla of the fallopian tubes
Which cells produce the majority of estradiol? A) The cells of the corpus luteum B) The cells of anterior pituitary C) Endometrial cells D) Granulosa cells of the follicle
D) Granulosa cells of the follicle
Over the counter pregnancy tests are based on the detection of a specific hormone excreted in urine early in the pregnancy. This hormone is: A) Progesterone B) Pregnenolone C) Estradiol D) Human chorionic gonadotropin (HCG)
D) Human chorionic gonadotropin (HCG)
Which one of the following statements regarding the function of the placenta is FALSE? A) The placenta is a source of progesterone during the late trimesters of pregnancy B) The trophoblasts contributes the fetal portion of the placenta C) At the point of implantation, the endometrium differentiates into a layer of decidual cells D) Late in pregnancy, progesterone is produced through a coordinated interplay of the mother and the placenta, and the fetus.
D) Late in pregnancy, progesterone is produced through a coordinated interplay of the mother and the placenta, and the fetus.
What tissue in the mother provides the increased estradiol and progesterone necessary for maintenance of pregnancy? A) Ovary B) Liver C) Adrenal D) Placenta
D) Placenta
Which of the following is a source of estrogen and progesterone during the last 7 months of pregnancy? A) Anterior pituitary B) Corpus luteum C) Ovary D) Placenta
D) Placenta
Regular consistent breast-feeding of a newborn can result in a period of decreased fertility for the nursing mother. This decreased fertility is because: A) Oxytocin inhibits growth and development of the endometrium B) Regular breast-feeding inhibits production to estrogen, which leads to decreased libido. C) Prolactin secretion "rescues" the corpus luteum and maintains progesterone production D) Prolactin inhibits ovulation by inhibiting the synthesis and release the gonadotropin-releasing hormone (GnRH)
D) Prolactin inhibits ovulation by inhibiting the synthesis and release the gonadotropin-releasing hormone (GnRH)
Which one of the following statements about prolactin is correct? A) Prolactin initiates ovulation B) Prolactin causes milk ejection during suckling C) Prolactin inhibits growth of breast tissue D) Prolactin secretion is decreased by dopamine
D) Prolactin secretion is decreased by dopamine
Regarding the sequence of events known as the ovarian cycle, which of the following statements is FALSE? A) The anterior pituitary releases FSH and LH B) FSH stimulates a follicle to develop C) The hypothalamus releases GnRH D) The developing follicle produces progesterone
D) The developing follicle produces progesterone
4 to 5 days of menses corresponded to how many days of the next menstrual cycle?
Days 0 to 4 or 5
Elevated levels of which hormone has a positive feedback effect on the anterior pituitary, upregulating GnRH receptors in the anterior pituitary, causing further secretion of FSH and LH?
Estradiol
The follicular phase is dominated by what hormone?
Estradiol
If there is no fertilization there is a decrease in what 2 hormones?
Estradiol & Progesterone
Corpus luteum synthesizes what 2 hormones?
Estradiol and Progesterone
What 2 hormones are steroid hormones secreted by the follicle and corpus luteum of the ovary?
Estradiol and Progesterone
A decrease in what hormone leads to a decrease in blood levels of calcium?
Estrogen
What hormone inhibits osteoclast activity?
Estrogen
What hormone is involved in calcium metabolism?
Estrogen
The corpus luteum is responsible for the production of what 2 hormones?
Estrogen & Progesterone
The release of GnRH is inhibited by what 2 hormones?
Estrogen and Progesterone
What 2 hormones are synthesized by the ovarian follicles through the combined functions of the granulosa cells and the theca cells?
Estrogen and Progesterone
What hormone stimulates aromatase?
FSH
As women approach their mid-40s to mid-50s, their ovaries begin to lose their sensitivity to which 2 hormones causing menopause?
FSH & LH
Anterior pituitary hormones:
FSH and LH
What hormones act on the ovaries for follicular development and ovulation and synthesis of the females sex steroid hormones?
FSH and LH
The corpus luteum regresses during the next 14 days (the second half of the menstrual cycle) and is replaced by a scar called the corpus albican, if what does not occur?
Fertilization
The corpus luteum will continue to secrete hormones until the placenta assumes this role, later in pregnancy, if what occurs?
Fertilization
What hormone stimulates development of the follicles in the ovaries?
Follicle stimulating hormone (FSH)
FSH and LH stimulate synthesis and secretion of estradiol by what cells?
Follicular cells
The initial increase in FSH stimulates follicular recruitment and maturation in what phase of the menstrual cycle?
Follicular phase
The pituitary gland releases FSH in what phase of the menstrual cycle?
Follicular phase
What phase of the menstrual cycle starts on the first day of menstruation and ends with ovulation?
Follicular phase
Hypothalamic hormone:
GnRH
What hormone is delivered directly to the anterior lobe of the pituitary in high concentration, resulting in a pulsatile secretion of FSH and LH?
GnRH
What hormone stimulates the secretion of the pituitary gonadotropins LH & FSH?
Gonadotropin-releasing hormone (GnRH) via hypothalamic releasing factor
Androstenedione is converted to estrogen by what cells?
Granulosa cells
What cells are the source of estradiol?
Granulosa cells
What cells express the enzyme aromatase?
Granulosa cells
The corpus luteum is formed by the action of which hormone on the mature preovulatory follicle?
LH
The onset of pubertal maturation is heralded by the development of a pattern of steady acceleration in pulsatility of what hormone?
LH
The persistent rapid GnRH pulses increases which hormone in the menstrual cycle?
LH
What hormone initiates Ovulation?
LH
What hormone maintains steroid hormone production by the corpus luteum during the luteal phase of the menstrual cycle?
LH
What hormone stimulates formation of the Corpus Luteum?
LH
In what phase does hormone production shift to the corpus luteum?
Luteal phase
In what phase of the menstrual cycle, the major hormonal secretion of the ovaries is progesterone?
Luteal phase
LH pulse frequency is slow in what phase?
Luteal phase
Preparation for Fertilization/Pregnancy is a function of what phase?
Luteal phase
The high levels of progesterone during this phase stimulate secretory activity of the endometrium and increase its vascularity.
Luteal phase
What phase is dominated by negative feedback effects of progesterone?
Luteal phase
What hormone is responsible for stimulation of estradiol and progesterone production by the ovaries?
Luteinizing hormone (LH)
What hormone is responsible for the development of ova, induction of ovulation?
Luteinizing hormone (LH)
What hormone stimulates development of the corpus luteum in the ovaries?
Luteinizing hormone (LH)
Menstrual periods become less frequent and finally cease during what?
Menopause
Regression of the corpus luteum and the abrupt loss of estradiol and progesterone cause the endometrial lining and blood to be sloughed during what?
Menses
Increasing LH further stimulates estradiol secretion, culminating in positive estradiol feedback to produce what?
Mid-cycle LH surge
What is menarche?
Onset of the menstrual cycle
What are the 2 functions of the ovaries that are controlled by the hypothalamic-pituitary axis?
Oogenesis & secretion of female sex steroid hormones
During the luteal phase, the corpus luteum develops in what?
Ovary
What occurs at midcycle?
Ovulation
The burst of FSH and LH secretion, triggers ovulation of the mature oocyte describes what?
Ovulatory surge
The period of development of the fetus is called?
Pregnancy
After ovulation, granulosa cells turn into granulosa lutein cells that produce what hormone?
Progesterone
Following ovulation, the production of what hormone increases?
Progesterone
One of the actions of which hormone is negative feedback on the anterior pituitary to inhibit secretion of FSH and LH?
Progesterone
What hormone supports & maintains a pregnancy?
Progesterone
What hormone supports the implantation of a fertilized egg in the uterus?
Progesterone
If fertilization has not occurred, what happens?
The corpus luteum regresses
LH pulse frequency increasingly speeds up during what phases?
The follicular and the pre-ovulatory phases
What cells produce androstenedione?
Theca cells
What cells synthesize and secrete progesterone?
Theca cells
