Menopause
Introduction0:00–0:36
In females, the reproductive period, or fertility period refers to the years of monthly menstrual cycles between the first menstrual period, which happens at puberty and then the permanent stopping of menstrual cycles - which is called menopause.
Menopause usually sets in around age 50, and it’s preceded by a couple of years of hormonal and physical changes and this is called perimenopause.
To be more specific, a woman’s entered menopause when an entire year has passed since her last menstrual period. During the reproductive period, the ovaries have basically got a ton of ovarian follicles scattered inside them.
Reproductive Period0:36–1:19
And each ovarian follicle is made up of a ring of granulosa and theca cells surrounding a primary oocyte the core. And during each menstrual cycle, one of these follicles ruptures at ovulation, and it releases the oocyte out into the fallopian tube - where it can be fertilized by a sperm, or it can just carry on down its path and you don’t get pregnant.
So the weird thing is, even though females are born with millions of follicles, only about 400 of them are actually mature enough to release their oocyte throughout the lifetime.Anyway, all of this process is ultimately controlled by the hypothalamus, which is all the way away from the gonads up in the brain.
Hormonal Regulation1:19–3:10
And the hypothalamus secretes gonadotropin releasing hormone, or GnRH, which travels to the nearby pituitary gland and makes it secrete two hormones of its own - follicle-stimulating hormone, or FSH, and luteinizing hormone, or LH.
FSH and LH then make the ovarian follicles secrete sex hormones. So, the theca cells make androstenedione, a sex hormone precursor that the granulosa cells convert into estradiol - a member of the estrogen family - and progesterone.
The menstrual cycle on average lasts about 28 days, and for the first two weeks, which are called the follicular phase, the granulosa cells make more estrogen sends a negative feedback signal to the pituitary which inhibits the production of FSH; likewise, progesterone inhibits LH production during the second half of the menstrual cycle - so hormone levels are constantly regulated, and this leads to a cyclic and predictable pattern in hormone secretion during the reproductive period.
During each menstrual cycle, a couple of follicles are stimulated by FSH and LH, until one of them emerges as the dominant follicle and ruptures at ovulation, and the rest of them , well, it’s pretty bleak really, they just degenerate off and die.
Over time, many ovarian follicles degenerate, and the ones that remain become less and less sensitive to FSH and LH. This goes on until menopause, when there are no remaining follicles responding to gonadotropins, and that causes the menstrual cycles to cease entirely.
Now, a couple of years before menopause, the woman enters a transition period called perimenopause. And during perimenopause, the ovaries have a lot less functional follicles, so the menstrual cycles preceding menopause are often anovulatory.
Perimenopause3:10–5:41
Anovulatory means, without ovulation, and that’s because none of the follicles are responsive enough to FSH and LH stimulation in order to mature and release the oocyte at ovulation.
The lack of ovulation can cause missed or irregular periods, and they become more irregular and more infrequent as the ovarian follicle starts to run out even more.
And fewer follicles also means less estrogen and progesterone, so less inhibition on the hypothalamus and the pituitary.
And in turn, the hypothalamus and pituitary produce more frequent, larger bursts of GnRH, FSH and LH - the difference is, though, the pattern of secretion is much more erratic than during the reproductive period, this erraticness, along with decreasing estrogen levels can cause a bunch of problems and these include hot flashes and night sweats which can lead to trouble sleeping, and also vaginal dryness, which can lead to dyspareunia which is pain during sex.
Also, estrogen normally has a protective effect on both the cardiovascular system where it helps to keep the blood vessels’ walls nice and flexible to accommodate blood flow, as well as the skeleton, where it helps sustain bone density.
So, low levels of estrogen can also lead to complications like cardiovascular disease and osteoporosis. So women entering menopause should have their LDL cholesterol levels checked, and, if high, dietary changes or medical therapy with statins may be required.
Osteoporosis is diagnosed using a dual-energy x-ray absorptiometry, or a DXA, test - and screening should start at 65 in the general female population, and 60 in smokers.
This test measures bone mineral density at different sites throughout the body, like the lower spine and hips, and results come back as a T score and a Z score.
A T score 2.5 standard deviations below the mean at any site confirms osteoporosis. Finally, changes in hormone levels can also impact the mood, so women going through menopause may experience irritability or mood swings.
So, even though transitioning into menopause is a natural step in the aging of the female reproductive system, these symptoms may have a negative impact on overall well-being.
Menopause5:41–7:10
The good news though, is that the body can adjust to the hormone changes, so they actually go away on their own after a couple of years.
But in the meantime, there are tons of ways that we alleviate them. For hot flashes and night sweats it’s really useful to avoid “triggers” like hot drinks and spicy foods, as well as, just, maintaining a cool ambient temperature.
Additionally, selective serotonin reuptake inhibitors or SSRIs like paroxetine or serotonin and norepinephrine reuptake inhibitors or SNRIs like venlafaxine can help with both hot flashes and psychological symptoms like mood swings and irritability.
In some cases, hormone replacement therapy with estrogen can also be used to relieve hot flashes - however, all women with an intact uterus need a progestin in addition to estrogen to prevent endometrial hyperplasia and cancer.
Women who have undergone hysterectomy should not receive a progestin, because it’s key benefit is prevention of endometrial hyperplasia and carcinoma, and that’s no longer relevant.
For vaginal dryness, there are things like vaginal estrogen creams and lubricants that can be during sex to help with pain.
And in an attempt to prevent osteoporosis, calcium and vitamin D supplements can be used. If osteoporosis is diagnosed, medical therapy with bisphosphonates should be initiated.
Review7:10–7:55
OK, so as a quick recap, menopause refers to the natural halting of the monthly menstrual cycles and this is because of the depletion of ovarian follicles.
It’s usually considered that a woman has entered menopause when more than 1 year has passed since her last menstrual period.
This usually happens around the age of 50, and it’s preceded by a couple of years of hormonal changes may manifest as hot flashes and night sweats, as well as mood changes.
Avoiding certain foods and maintaining a cool ambient temperature, using vaginal creams and lubricants, as well as certain medications, can help manage the symptoms
- "Medical Physiology" Elsevier (2016)
- "Physiology" Elsevier (2017)
- "Human Anatomy & Physiology" Pearson (2018)
- "Principles of Anatomy and Physiology" Wiley (2014)
- "Menopause" Medical Clinics of North America (2015)
- "Hormonal and Nonhormonal Treatment of Vasomotor Symptoms" Obstetrics and Gynecology Clinics of North America (2015)
- "Use of Plant-Based Therapies and Menopausal Symptoms" JAMA (2016)
- "EMAS clinical guide: Assessment of the endometrium in peri and postmenopausal women" Maturitas (2013)
No notes for this video yet
Try adding a note below