Vallano- Female Repro Endocrinology; Fert, part, lact Flashcards
FSH stimulates development of follicles during which phase of the ovarian cycle?
Follicular phase
What are the primary phases of the ovarian cycle?
- Follicular phase
- Ovulatory phase
- Luteal phase
LH surge causes rupture of the ovarian follicle during which phase of the ovarian cycle?
Ovulatory phase
LH converts the ruptured follicle into a corpus luteum during which phase of the ovarian cycle?
Luteal phase
The thickness of the endometrium increases 1-2mm to 8-10 mm during which uterine phase?
Proliferative phase
This phase is dominated by estrogens and is variable in length
This uterine phase is dominated by progesterone and has a fixed length of 14 days following ovulation
Secretory phase: progesterone promotes accumulation of glycogen and increases glandular secretions and increased vascularity
This uterine phase is associated with prostaglandin-mediated vasoconstriction of spiral arteries and local ischemic injury/inflammation. This phase is also associated with the regression of the corpus luteum
Menstrual phase (5 days)
_____ in the follicular phase promotes proliferation of the endometrium and primes the uterus for progesterone actions
estradiol
________ (luteal phase) converts the proliferation of uterus to a secretory uterus
Progesterone
Where is GnRH released from, where does it act? What hormone are released?
What has a negative feedback on this axis?
Released from hypothalamus and travels to anterior pituitary to release FSH/LH (Gonadotropins)
Estrogen synthesized from developing follicles have neg feedback on the axis (to inhibit GnRH release…with helo pf progesterone)…BUT in later follicular phase, blood estrogen reaches a high enough level that it initiates a positive feedback causing a surge of LH that provokes ovulation (day 14)
In Luteal phase _______ provides negative feed back to FSH and not LH
What cell types do FSH and LH act on?
Inhibin released from granulosa cells
FSH acts on granulosa
LH acts on theca cells (but can act on granulosa cells)
Ovulation and LH surge occurs at about what day?
14th day of menstral cycle
what 2 hormones does the corpus luteum release?
Estrogen and progresterone
What is the cause of menopause?
A. Reduced levels of gonadotropic hormones secreted from the anterior pituitary gland
B. Reduced responsiveness of the follicles to the stimulatory effects of gonadotropic hormones
C. Reduced rate of secretion of progesterone from the corpus luteum
D. Reduced numbers of follicles available in the ovary for stimulation by gonadotropic hormones
Reduced numbers of follicles available in the ovary for stimulation by gonadotropic hormones
A likely explanation for the failure of granulosa cells to produce estrogens when cultured alone is
Estrogens are produced in a two-cell system of granulosa and theca cells. Theca cells provide androgen precursors under the influence of LH. Granulosa cells use androgens to synthesize estrogens, which is accomplished via FSH-stimulated aromatase activity.
A female athlete who took testosterone-like steroids for several months stopped having normal menstrual cycles. What is the best explanation for this observation?
Testosterone inhibits the hypothalamic secretion of GnRH and the pituitary secretion of LH and FSH
The cells of the anterior pituitary that secrete LH and FSH, along with the cells of the hypothalamus that secrete GnRH, are inhibited by both estrogen and testosterone., The steroids taken by the woman caused sufficient inhibition to result in cessation of the monthly menstrual cycle.
The luteinizing hormone surge measured during the ovulatory phase of the menstrual cycle results from positive feedback exerted by which of the following hormones.
estrogen
What accompanies sloughing of the endometrium during the endometrial cycle in a normal woman?
A decrease in both progesterone and estrogen
At the end off the luteal phase, the corpus luteum is resorbed and fails to produce progesterone and estradiol, making levels fall precipitously and causing the endometrium to slough.
_____ initiates contractions and they are sustained by _____ and more ______
prostaglandins
oxytocin and more prostaglandins
_______ promotes milk let-down & uterine contractility.
______ promotes milk synthesis
Oxytocin
Prolactin
Both are released in response to suckling
What 2 hormones are important for breast development during pregnancy but prevent the actual secretion of milk?
Estrogen and progesterone
It is the sudden loss of these steroids after delivery that allows prolactin to work (inhibiting dopamine)
_____ has the same stimulatory effect as LH on the corpus luteum.
HCG has the same stimulatory effect as LH on the corpus luteum. Administration of HCG would cause the corpus luteum to continue to secrete estrogen and progesterone, preventing degradation of the endometrium and onset of menstruation.
A 37-year old-woman who is breast-feeding her 4-month-old son is taking the train to see her mother who lives several hours away. When the woman hears the cry of another infant, she notices that milk has been expressed from both her breasts. The release of which hormone can account for this response? A. Estrogen B. Inhibin C. Oxytocin D. Progesterone E. Prolactin
C. oxytocin
The lactation reflex occurs in response to a baby suckling, which produces a surge of oxytocin secretion and milk ejection. This reflex can be conditioned by stimuli such as the sound of a baby crying.
A 30-year-old woman is breast-feeding her infant. During suckling, which of the following hormonal responses is expected?
A. Increased secretion of antidiuretic hormone (ADH) from the supraoptic nuclei
B. Increased secretion of ADH from the paraventricular nuclei
C. Increased secretion of oxytocin from the paraventricular nuclei
D. Decreased secretion of neurophysin
E. Increased plasma levels of both oxytocin and ADH
Increased secretion of oxytocin from the paraventricular nuclei
Implantation normally occurs _____days after ovulation.
Implantation normally occurs 6 - 7 days after ovulation.
The placenta secretes both _____ and _____ from the trophoblast cells.
The placenta secretes both estrogen and progesterone from the trophoblast cells.
During pregnancy, the uterine smooth muscle is quiescent. During the 9th month of gestation the uterine muscle becomes progressively more excitable. What factors contribute to the increase in excitability?
Progesterone synthesis by the placenta decreases
Very high plasma concentration of progesterone maintains the uterine muscle in a quiescent state during pregnancy. In the final month of gestation the concentration of progesterone begins to decline, increasing the excitability of the muscle.
Why is milk produced by a woman only after delivery, not before?
High levels of progesterone and estrogen during pregnancy suppress milk production
RU486 causes abortion if it is administered before or soon after implantation. What is the specific effect of RU486?
It blocks progesterone receptors so that progesterone has no effect within the body
Progesterone is required to maintain the decidual cells of the endometrium. If progesterone levels fall, as they do during the last days of a nonpregnant menstrual cycle, menstruation will follow within a few days, with loss of pregnancy. Administration of a compound that blocks the progesterone receptor during the first few days after conception will terminate the pregnancy.
- Menopause is typically diagnosed by a rise in what hormone?
- Symptoms of menopause are typically due to a lack in what hormone?
- FSH
2. Estrogen
