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.