PHY3181 Female Reproduction Exam With
Complete Solutions
Outline the GnRH --> Gonadotrope process. - ANSWER Hypothalamus--> GnRH release
Median eminence --> GnRH storage and release
Portal vessels --> GnRH transport
Ant pit --> LH and FSH release
Outline what types of hormones you see in female reproductive endocrinology. -
ANSWER Brain- kisspeptin
Gonadotrophins- LH and FSH
Steroid hormones- progesterone and estradiol
Peptide hormones- GnRH, Inhibin A and B
Outline the hormones needed for the maturation of the follicles. - ANSWER Recruitment
of primordial follicle: GnRH INDEPENDENT, no hormones needed
Production of antral follicle: FSH
Production of Graafian follicle: High estradiol, low FSH
When are oestrogen and progesterone released in the uterine cycle in the highest
amounts? - ANSWER Estrogen: during follicular phase
Helps build endometrium lining
Progesterone: during luteal phase by corpus luteum
Remodels endometrium for implantation
Does the uterine cycle directly respond to hormones from the ant pit? - ANSWER No the
ovary responds to LH and FSH from ant pit, which then releases oestrogen and
progesterone which act on endometrium.
What are the three layers of the endometrium? - ANSWER Perimetrium: outermost
muscular layer
Myometrium: bulky, middle muscular layer (contracts to expel baby)
Endometrium: mucosal inner layer
,What are the two layers of the endometrium and which one sheds? - ANSWER
Functional layer: shed during menstruation in response to ovarian hormones
Basal layer: unresponsive to ovarian hormones
Outline days 1-5 (menstrual phase) of the uterine cycle. - ANSWER - shedding of
functional layer of endometrium
- estrogen and progesterone LOW
Outline days 6-14 (proliferative phase) of the uterine cycle. - ANSWER - rebuilding of
functional layer of endometrium from 1mm to about 5mm thick (stem cell regeneration)
- proliferation of glandular epithelium, stroma and blood vessels
- cervical mucous less sticky to allow entry of sperm
- Stimulated by ovarian ESTROGENS
Outline days 15-28 (secretory phase) of the uterine cycle. - ANSWER - Occurs just after
ovulation (LH surge)
- Endometrium prepared for implantation
- glands enlarge, arteries elongate, glycogen secreted
- requires progesterone and oestrogen from corpus luteum
- If fertilisation does not occur, corpus luteum degenerates
- Low progesterone leads to spasm of arteries, and low oxygen levels
- menses begins again
What is the two step two cells model of oestrogen synthesis in the ovary? - ANSWER -
Ant pit releases LH
- Acts on thecal cells
- Thecal cells produce androgens
- Androgens released to granulosa cells next door
- Granulosa cells convert androgens to estrogens
Biosynthesis of steroid hormones. - ANSWER Estrogen and progesterone main steroid
hormones.
- Every female receiving stimulus from ant pit needs to be able to convert androgen to
oestrogen
- Cholesterol precursor for both steroid hormones.
,Which cells do FSH and LH act on in the ovary? - ANSWER - LH acts directly on theca
cells
- FSH acts directly on granulosa cells
Where is progesterone synthesised? - ANSWER - Corpus luteum, does not occur until
after ovulation but builds endometrial lining
Outline the estrogen positive/ negative feedback loop - ANSWER - Estrogen negative
feedback during most of the cycle to hpg axis
- Switches to positive feedback immediately prior to ovulation at 12-14 day period
- Cause LH surge
- Progesterone needs to be low to allow pos feedback of estrogen
Where are inhibin A and B produced? - ANSWER In the granulosa cells of the developing
follicle (early antrum)
When are inhibin A and B elevated? - ANSWER - Inhibin A elevated in luteal phase
- Inhibin B elevated in mid follicular phase
Inhibin B feedback - ANSWER Inverse relationship observed between Inhibin B and FSH
- FSH stimulates follicles to develop in luteal phase of preceding cycle
- The developing follicles produce increasing levels of inhibin B during
follicular phase of cycle
- Inhibin B acts on PITUITARY to inhibit FSH (MORE THAN INHIBIN A)
- As non-dominant follicles die by atresia, Inhibin B levels fall - remove
inhibition on FSH
Outline three roles of oestrogen. - ANSWER - Increase growth of uterus, vagina,
fallopian tubes
- Initial growth spurt in puberty
- Contribute to cardiac, bone and mental health
- (with progesterone) maintain pregnancy and stimulate breast growth
Combined oral contraceptives. - ANSWER - Low levels estradiol and high progesterone
- Suppress gonadotropin secretion = inhibit follicular development and prevent LH surge
to prevent ovulation.
, - Prevent hormonal fluctuations
What does the progesterone only pill do? - ANSWER - Decreases pulse frequency of
GnRH (LH and FSH)
- Inhibition of follicular development
- Progestagen negative feedback and absence of estradiol positive feedback = no LH
surge
- No or reduced ovulation
Emergency (morning after) pill - ANSWER - Prevent or delaying ovulation, if it has not
already occurred
- Change mucus and cervical environment
What are the two types of pills that make ovulation better in assisted reproductive
technologies (ART) and what do they do? - ANSWER - GnRH agonists or GnRH
antagonists
- Allows FSH and LH to be more function;
DANGER - lots of follicles = lots of estradiol → positive feedback on LH
GnRH agonist - ANSWER • Desensitises and down-regulates receptor - control
endogenous gonadotropins
• Exogenous gonadotropins
- FSH for follicle development
- hCG (instead of LH) for ovulation
GnRH antagonist - ANSWER • Highly effective at inhibiting GnRH mediated
gonadotropins
• Short term, rapidly reversible effects
• Prevents LH surge
• Exogenous gonadotropins
Complete Solutions
Outline the GnRH --> Gonadotrope process. - ANSWER Hypothalamus--> GnRH release
Median eminence --> GnRH storage and release
Portal vessels --> GnRH transport
Ant pit --> LH and FSH release
Outline what types of hormones you see in female reproductive endocrinology. -
ANSWER Brain- kisspeptin
Gonadotrophins- LH and FSH
Steroid hormones- progesterone and estradiol
Peptide hormones- GnRH, Inhibin A and B
Outline the hormones needed for the maturation of the follicles. - ANSWER Recruitment
of primordial follicle: GnRH INDEPENDENT, no hormones needed
Production of antral follicle: FSH
Production of Graafian follicle: High estradiol, low FSH
When are oestrogen and progesterone released in the uterine cycle in the highest
amounts? - ANSWER Estrogen: during follicular phase
Helps build endometrium lining
Progesterone: during luteal phase by corpus luteum
Remodels endometrium for implantation
Does the uterine cycle directly respond to hormones from the ant pit? - ANSWER No the
ovary responds to LH and FSH from ant pit, which then releases oestrogen and
progesterone which act on endometrium.
What are the three layers of the endometrium? - ANSWER Perimetrium: outermost
muscular layer
Myometrium: bulky, middle muscular layer (contracts to expel baby)
Endometrium: mucosal inner layer
,What are the two layers of the endometrium and which one sheds? - ANSWER
Functional layer: shed during menstruation in response to ovarian hormones
Basal layer: unresponsive to ovarian hormones
Outline days 1-5 (menstrual phase) of the uterine cycle. - ANSWER - shedding of
functional layer of endometrium
- estrogen and progesterone LOW
Outline days 6-14 (proliferative phase) of the uterine cycle. - ANSWER - rebuilding of
functional layer of endometrium from 1mm to about 5mm thick (stem cell regeneration)
- proliferation of glandular epithelium, stroma and blood vessels
- cervical mucous less sticky to allow entry of sperm
- Stimulated by ovarian ESTROGENS
Outline days 15-28 (secretory phase) of the uterine cycle. - ANSWER - Occurs just after
ovulation (LH surge)
- Endometrium prepared for implantation
- glands enlarge, arteries elongate, glycogen secreted
- requires progesterone and oestrogen from corpus luteum
- If fertilisation does not occur, corpus luteum degenerates
- Low progesterone leads to spasm of arteries, and low oxygen levels
- menses begins again
What is the two step two cells model of oestrogen synthesis in the ovary? - ANSWER -
Ant pit releases LH
- Acts on thecal cells
- Thecal cells produce androgens
- Androgens released to granulosa cells next door
- Granulosa cells convert androgens to estrogens
Biosynthesis of steroid hormones. - ANSWER Estrogen and progesterone main steroid
hormones.
- Every female receiving stimulus from ant pit needs to be able to convert androgen to
oestrogen
- Cholesterol precursor for both steroid hormones.
,Which cells do FSH and LH act on in the ovary? - ANSWER - LH acts directly on theca
cells
- FSH acts directly on granulosa cells
Where is progesterone synthesised? - ANSWER - Corpus luteum, does not occur until
after ovulation but builds endometrial lining
Outline the estrogen positive/ negative feedback loop - ANSWER - Estrogen negative
feedback during most of the cycle to hpg axis
- Switches to positive feedback immediately prior to ovulation at 12-14 day period
- Cause LH surge
- Progesterone needs to be low to allow pos feedback of estrogen
Where are inhibin A and B produced? - ANSWER In the granulosa cells of the developing
follicle (early antrum)
When are inhibin A and B elevated? - ANSWER - Inhibin A elevated in luteal phase
- Inhibin B elevated in mid follicular phase
Inhibin B feedback - ANSWER Inverse relationship observed between Inhibin B and FSH
- FSH stimulates follicles to develop in luteal phase of preceding cycle
- The developing follicles produce increasing levels of inhibin B during
follicular phase of cycle
- Inhibin B acts on PITUITARY to inhibit FSH (MORE THAN INHIBIN A)
- As non-dominant follicles die by atresia, Inhibin B levels fall - remove
inhibition on FSH
Outline three roles of oestrogen. - ANSWER - Increase growth of uterus, vagina,
fallopian tubes
- Initial growth spurt in puberty
- Contribute to cardiac, bone and mental health
- (with progesterone) maintain pregnancy and stimulate breast growth
Combined oral contraceptives. - ANSWER - Low levels estradiol and high progesterone
- Suppress gonadotropin secretion = inhibit follicular development and prevent LH surge
to prevent ovulation.
, - Prevent hormonal fluctuations
What does the progesterone only pill do? - ANSWER - Decreases pulse frequency of
GnRH (LH and FSH)
- Inhibition of follicular development
- Progestagen negative feedback and absence of estradiol positive feedback = no LH
surge
- No or reduced ovulation
Emergency (morning after) pill - ANSWER - Prevent or delaying ovulation, if it has not
already occurred
- Change mucus and cervical environment
What are the two types of pills that make ovulation better in assisted reproductive
technologies (ART) and what do they do? - ANSWER - GnRH agonists or GnRH
antagonists
- Allows FSH and LH to be more function;
DANGER - lots of follicles = lots of estradiol → positive feedback on LH
GnRH agonist - ANSWER • Desensitises and down-regulates receptor - control
endogenous gonadotropins
• Exogenous gonadotropins
- FSH for follicle development
- hCG (instead of LH) for ovulation
GnRH antagonist - ANSWER • Highly effective at inhibiting GnRH mediated
gonadotropins
• Short term, rapidly reversible effects
• Prevents LH surge
• Exogenous gonadotropins
