Module 3: Physiology of the Female Reproductive Cycle Flashcards
What does menarche mean?
Very first menstrual flow
What does menses mean?
Regular monthly flow in the reproductive years
What does perimenopausal mean:
A women at the near end of her mentrual years
When does perimenopausal happen?
Begins around the late 40’s
How long does the perimenopausal years happen?
Around 10 years in duration
What is menopause?
When menstrual cycle ceases altogether
When is a women officially in menopause?
1 year without a menstrual period
What are female menstrual cycle hormones? 6
- GnRH
- FSH
- LH
- Estrogen
- Progesterone
- Relaxin
What are the three key areas to consider in the menstrual cycle?
- Hormones
- Ovaries and follicles
- Endometrium
What does FSH and LH do?
Stimulate the ovaries
Where are gonadotropins produced?
Hormones produced by the anterior pituitary
What does FSH do?
Stimulates the growth of follicles
Many follicles will be stimulated but how many will mature?
Only one will mature and produce a egg
What does LH do?
Stimulates the follicles also but to a lesser extend compared to FSH
A surge in LH is responsible for what?
Ovulation
LH supports the growth of what?
Corpus luteum but does not maintain it
In pregnancy HCG does what?
Maintains the corpus luteum
Dominant follicle after ovulation is referred to as what?
Corpus luteum
What are some ovarian steroids? 3
- Estrogen
- Progesterone
- Relaxin
Estrogen is secreted from what?
Granulosa cells lining the follicle
Peak secretion of estrogen occurs when?
Just before ovulation
What must happen for LH to surge?
Estrogen must hit a threshold
What is the cause for proliferation of endometrium?
Estrogen
Estrogen is responsible for what?
Secondary sex characteristics
Progesterone is secreted by what?
Corpus luteum
Peak concentration of progesterone happens when?
about 7 days after ovulation
Progesterone induces what?
Secretory activity and hypertrophy of the endometrium
Progesterone inhibits the secretion of what?
LH
What does relaxin do?
- Relaxes the symphysis pubis during fetal delivery
- Helps dilate the cervix to promote sperm mobility
- Also dilates the cervix in labor during fetal delivery
The menstrual cycle is assumed to be how long?
28 days
What is the stages of the menstrual cycle?
- Menstruation day 1-5
- Proliferation phase day 6-14
- Ovulation day 14
- Secretory day 14-28
The proliferative phase is also known as what?
Follicular phase
The secretory phase is also known as what?
Luteal phase
What does the hypothalamus do for menstruation?
It releases GnRH to stimulate the anterior pituitary to release FSH and LH
What does the FSH do besides stimulating the follicles?
It stimulates the ovaries to release estrogen and progesterone
What does the LH stimulate?
It stimulates the ovaries to release relaxin
What happens during the bleeding phase? 2
- Ovarian hormone levels are low causing hypothalamus to produce GnRF
- This causes pituitary to produce FSH and LH
A Graafian follicle matures by what day? And is accompanied by what?
Day 13 and is accompanied by an increase in estrogen
What happens during the physiology day of the menstrual cycle? 3
- Estrogen hits a threshold which causes LH to surge causing ovulation
- The Graafian follicle bursts and becomes the corpus luteum
- Progesterone increases and estrogen decreases a little
What happens if fertilization does not occur after ovulation? 2
- corpus luteum regresses and progesterone decreases
- Withdrawal of the hormones causes menstruation to begin, and the cycle reinitiates again
What is mittelschmerz?
Pain at ovulation
What are some symptoms of menstruation?
- Fluid retention or weight gain in the luteal phase
- Rise in body temperature at ovulation due to progesterone
What does the endometrium look like during the menstrual phase?
It is thin
What can we see during the menstrual phase on the ultrasound? 3 (in the canal)
- potential blood in the canal
- Anechoic areas within canal
- Thin endometrium
During postmenopause what is the endometrium thickness?
1-3 mm
What is the cumulus oophorus?
When the ovum with its layers, the corona radiata and zona pellucida protrudes from the wall of the follicle into the follicular fluid
What is the cumulus oophorus a sign of?
Ovulation is about to occur
What happens to the spiral arterioles during the proliferative phase?
They undergo lengthening via mitosis (so fast they coil)
What happens to the endometrium post ovulation with progesterone influence?
It becomes edematous
Without fertilization, the corpus luteum does what? 3
- Degenerates and estrogen and progesterone decrease
- Endometrium shrinks causing the circulation to be cut off
- Necrosis of the tissue occurs and then it is shed
What happens to the endometrium with early pregnancy?
The endometrium thickens further due to the continued increase in progesterone produced by the corpus luteum
During early pregnancy with high levels of estrogen and progesterone what happens?
They hypothalamus is suppressed causing further menstrual cycles to stop
What forms when the corpus luteum degenerates? 2
- A corpus albicans
- A white scar forms which we can see with EV
A corpus fibrosum occurs when?
A follicle does not rupture
If a corpus fibrosum occurs when a follicle does not rupture what happens? 2
- Corpus luteum does not form
- The liquid is gradually absorbed and the follicle regresses, forming a scar
The hormone that triggers ovulation is what?
LH
A functional cyst on the ovary after ovulation has occurred is called what?
Corpus luteum
Where is estrogen produced?
From the granulosa cells lining the follicle