Female Reproductive System (+Ovulation) Flashcards
State the functions of the female reproductive system (4)
- steroidogenesis - produce sex hormones
- folliculogenesis - produce, maintain and transport viable oocytes
- fertilisation and pregnancy
- lactation
State the functions of steroidogenesis (4)
- controls secondary sexual characteristics
- controls folliculogenesis
- controls fertilisation and pregnancy
- controls parturition -> delivery
Explain how estrogen and progesterone are secreted starting from hypothalamic stimulus.
- hypothalamus secretes GnRH
- GnRH is transported to anterior pituitary via vascular link (primary and secondary capillary plexus) to stimulate secretion of LH and FSH
- LH and FSH are transported to the ovaries via bloodstream to stimulate secretion of oestrogen and progesterone.
State when ESTROGEN AND PROGESTERONE have POSITIVE FEEDBACK and NEGATIVE FEEDBACK MECHANISMS.
negative feedback mechanism - most of the menstrual cycle
positive feedback mechanism - day 12-14 of the menstrual cycle (where GnRH and LH spike to stimulate ovulation)
OOGENESIS:
- ____ oocytes ovulated during the entire reproductive years
- All primary ____ remain ____ at ____ of meiosis ____
- ____ is the main hormone to promote folliculogenesis/follicular development
OOGENESIS:
- 400 oocytes ovulated during the entire reproductive years
- All primary OOCYTES remain ARRESTED at PROPHASE of meiosis I
- FSH is the main hormone to promote folliculogenesis/follicular development
State the differences between spermatogenesis and oogenesis.
(1) CELL CYCLE
- Spermatogenesis = starts at interphase of mitosis, involves both mitosis and meiosis
- Oogenesis = starts at prophase I of meiosis, involves only meiosis
(2) MEIOSIS
- Spermatogenesis = both meiosis I and meiosis II are completed
- Oogenesis = starts at prophase I of meiosis I and stops at metaphase II of meiosis II
(3) OUTPUT
- Spermatogenesis = each primary spermatocyte produces 4 spermatozoa
- Oogenesis = each primary oocyte produces 1 oocyte
(4) LENGTH
- Spermatogenesis = 7 weeks
- Oogenesis = 13-50 years
(5) DURATION
- Spermatogenesis = Puberty - death
- Oogenesis = Birth - menopause
(6) REGULARITY
- Spermatogenesis = Every 65-70 days
- Ooegenesis = All at birth
(7) QUANTITY
- Spermatogenesis = millions/billions at a time
- Oogenesis = one oocyte/month (total of 400 oocytes)
State the steps in folliculogenesis.
(1) Primordial follicle
- primary oocyte (primordial follicle) arrested in prophase I as it requires a layer of follicular cells to develop
(2) Graafian follicle
- primary oocyte undergoes meiosis I and produces 1 polar body and 1 secondary oocyte (which is arrested at metaphase II)
(3) After fertilisation
- first polar body may or may not undergo meiosis II resulting in formation of 2 polar bodies (all polar bodies degnerate)
- ovulated secondary oocyte becomes ovum after ovulation
- if ovum is fertilised by sperm, meiosis II is completed and one more polar body is produced
CORPUS LUTEUM
- Early corpus luteum - ____ of follicle which transform into corpus luteum and secretes ____ to prepare ____ for possible implantation
- Mature corpus luteum - ____ production peaks
- Corpus luteum lasts for ____-____ days
- Corpus luteum undergoes ____ ____ to become corpus ____
CORPUS LUTEUM
- Early corpus luteum - REMNANTS of follicle which transform into corpus luteum and secretes PROGESTERONE to prepare ENDOMETRIUM for possible implantation
- Mature corpus luteum - PROGESTERONE production peaks
- Corpus luteum lasts for 10-14 days
- Corpus luteum undergoes LUTEAL REGRESSION to become corpus ALBICANS
Draw out the mechanism of action that produces estradiol.
State the functions of ESTRADIOL (9)
- development of female external genitalia
- female secondary sex characteristics
- ovarian folliculogenesis
- supports puberty
- thickening of endometrial lining
- promotes libido/sex drive
- promotes metabolism
- controls menstrual cycle
- positive feedback to hypothalamus and anterior pituitary gland –> increase estrogen release (day 12-14 of cycle)
State the sources of PROGESTERONE (3)
- LH influence –> granulosa cells in ovaries
- corpus luteum
- placenta (early stage pregnancy)
State the biological effects of PROGESTERONE (3)
- converts endometrium to secretory change for implantation
- reduce maternal immune response to allow individual to grow in uterus
- decrease contractility of uterine smooth muscle until fetus is ready to be delivered
State the biological effects of PROGESTERONE AND ESTROGEN.
**PROGESTERONE **
1. converts endometrium to secretory change for implantation
2. reduce maternal immune response
3. decrease contractility of uterine smooth muscles (until foetus is ready to be delivered)
OESTROGEN/ESTROGEN
1. development of female external genitalia
2. female secondary sex characteristics
3. ovarian folliculogenesis
4. thickening of endometrial lining
5. promotes libido
6. controls menstrual cycle
State the differences between ESTROGEN and PROGESTERONE.
(1) SOURCES
- estrogen - ovaries, placenta (late stage of pregnancy), corpus luteum
- progesterone - ovaries, placenta (early stage of pregnancy), corpus luteum
(2) SECONDARY SEXUAL CHARACTERISTICS
- estrogen - development
- progesterone - maintenance
(3) ENDOMETRIUM
- estrogen - proliferation
- progesterone - convert to secretory stage to prepare for implantation
(4) LACTATION
- estrogen - inhibits lactation
- progeesterone - inhibits lactation
(5) METABOLISM
- estrogen - anabolic
- progesterone - catabolic
(6) LEVELS IN MENSTRUAL CYCLE
- estrogen - increase before ovulation
- progesterone - increase after ovulation
(7) LIBIDO
- estrogen - increase
- progesterone - decrease
(8) CANCER RISK (breast/endometrial)
- estrogen - increase
- progesterone - decrease
OVULATION
- Normally produces ____ oocyte(s) at a time
- In the ____ of the menstrual cycle
- Promoted by sudden ____ of ____
- From the ____ follicle –> ____ –> releases ____ oocyte –> undergoes ____ if fertilised by sperm
- After ovulation, the ____ follicle becomes ____ ____ which secretes ____ and ____ (____ is higher)
- If not fertilised, the corpus luteum becomes corpus ____
OVULATION
- Normally produces 1 oocyte(s) at a time
- In the MIDDLE of the menstrual cycle
- Promoted by sudden INCREASE of LH
- From the GRAAFIAN follicle –> RUPTURES –> releases MATURE oocyte –> undergoes MEISOSIS II if fertilised by sperm
- After ovulation, the EMPTY follicle becomes CORPUS LUTEUM which secretes ESTROGEN and PROGESTERONE (PROGESTERONE is higher)
- If not fertilised, the corpus luteum becomes corpus ALBICANS
MENSTRUAL CYCLE (____-____ days)
- Basal body temperature ____ after ____
- LH and FSH ____ on day ____ (ovulation), ____ spike is bigger
- ____ is higher before ovulation as it is needed for ____ and ____
- ____ higher before ovulation as its functions are ____ on the endometrial lining
- ____ higher after ovulation as it is secreted by corpus ____ and also is for ____ phase of the endometrial lining in preparation for ____
MENSTRUAL CYCLE (24-35 days)
- Basal body temperature RISES after OVULATION
- LH and FSH SPIKE on day 14 (ovulation), LH spike is bigger
- FSH is higher before ovulation as it is needed for FOLLICULOGENESIS and OOGENESIS
- OESTROGEN higher before ovulation as its functions are PROLIFERATIVE on the endometrial lining
- PROGESTERONE higher after ovulation as it is secreted by corpus LUTEUM and also is for SECRETORY phase of the endometrial lining in preparation for IMPLANTATION
Draw out a diagram that depicts the MENSTRUAL CYCLE and the changes that occur to
1. body temperature
2. anterior pituitary hormones (FSH/LH)
3. ovarian hormones (oestrogen, progesterone)
4. uterine cycle (thickeness of lining)
State the differences between puberty in BOYS and GIRLS
