1. Anatomy and Physiology Female Reproductive System II
Marieb’s Human
Anatomy and Physiology
Ninth Edition
Marieb w Hoehn
Chapter 27
Female Reproductive System II
Lecture 20
Hormonal Control, Menstrual Cycle/Estrogens, the Climacteric, Female Breast
Slides 1-15; 80 min (with review of syllabus and Web sites) [Lecture 1]
Slides 16 – 38; 50 min [Lecture 2]
118 min (38 slides plus review of course Web sites and syllabus)

2. Review of Female Reproductive Cycle
Figure from: Hole’s Human A&P, 12th edition, 2010

3. Ovarian Cycle – Preovulatory (Follicular) Phase
Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001
(Graafian)
1.5 cm
Many
Few
One
Thecal and granulosa cells produce estrogens
8-10 days after beginning of cycle
10-14 days
(FSH)
(FSH) LH
Meiosis II started
Meiosis I
Estrogen

4. Ovarian Cycle – Postovulatory (Luteal) Phase
(Day 14)
12 days post ovulation
Lipids used to synthesize progestins, e.g., progesterone (prepares uterine lining for implantation) LH
If fertilization has not occurred LH
Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001

5. Hormonal Control of the Female Reproductive Cycle
Ovarian and uterine (menstrual) cycles must be coordinated
GnRH (Gonadotropin Releasing Hormone) is the controlling hormone of reproduction
Pulse frequency and amplitude (amount)
Without pulses, LH/FSH secretion (also in pulses) will stop
Changes in GnRH pulse frequency are controlled by estrogen (increase) and progestins (decrease)

6. Hormonal Regulation of Ovarian Activity
Figure from: Saladin, Anatomy & Physiology, McGraw Hill, 2007

7. Hormonal Regulation of Ovarian Activity
inhibits LH and FSH during most of the reproductive cycle
Estrogen is the predominant hormone prior to ovulation (follicular phase)
Progesterone is the predominant hormone after ovulation (luteal phase)
1-4 GnRH pulses/day
(Day 10)
36 GnRH pulses/day
48GnRH pulses/day
16-24 GnRH pulses/day
At pulses/day of GnRH, secretion of FSH predominates (2), and the estrogen produced by the developing follicle inhibits LH release.
At 36 pulses/day of GnRH (caused by increasing estrogen from tertiary follicles), LH secretion is stimulated and the previously inhibitory effect of estrogen on LH secretion now becomes stimulatory.
When GnRH is pulsing at about 48 pulses/day, there is massive release of LH from ant. Pit. Causing LH surge, triggering ovulation about h afterwards.
Figure from: Marieb, Anatomy & Physiology, Pearson, 2004

8. Pathways of Steroid Hormone Synthesis
Most abundant
Androstenedione is secreted by thecal cells (LH) of the primary follicles and then absorbed by the granulosa cells (FSH) and converted to estrogens.
Note three major female hormones; estradiol is most abundant
Cooperation of thecal and granulosa cells
Under influence of LH, thecal cells secrete androstenedione
Granulosa cells convert androstenedione into estradiol
Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001

9. Effects of Estrogens (20 sex characteristics)
development of breasts and ductile system of the mammary glands
increased adipose tissue in breasts, thighs, and buttocks
increased vascularization of skin
Maintenance of the function of accessory reproductive glands/organs
CNS effects, e.g., sex drive, “feminization”
Repair/growth of endometrium (following menses)

10. Uterine (Menstrual) Cycle
Figure from: Hole’s Human A&P, 12th edition, 2010
Functional
Basilar *
Proliferative phase – functional layer of endometrium thickens under the influence of estrogen
Secretory phase – Arteries elaborate and uterine glands enlarge, coil, and begin secreting glycogen under progesterone’s influence

11. Menarche and the Menstrual Cycle
First menstrual cycle (Latin mensis = month)
Typically begins around age 11-12
If menarche does not appear by age 16, considered amenorrhea (rhe(o)- = flow)
Menstrual cycles
Occur monthly unless interrupted by illness, stress, starvation, or pregnancy
Lack of menstrual period for 6 months or more is considered amenorrhea (secondary)
Painful menstruation is called dysmenorrhea – may result from uterine inflammation or conditions involving adjacent pelvic structures
Menarche does not appear until females have accumulated about 17% body fat; adult menstruation generally ceases if a woman’s body fat drops below 22%.
The formula to predict your body fat percentage, based on your current BMI, age, and gender (from
Child Body Fat % = (1.51 x BMI) - (0.70 x Age) - (3.6 x gender) + 1.4
Adult Body Fat % = (1.20 x BMI) + (0.23 x Age) - (10.8 x gender) - 5.4
where male gender= 1, female=0.

12. Overview of Female Reproductive Cycle
Figure from: Hole’s Human A&P, 12th edition, 2010
You should understand these events, and their timing, for the exam

13. Events of the Female Reproductive Cycle
Table 22.4 in Hole’s Anatomy & Physiology
Good textual review table for combined ovarian and uterine cycles
Figure from: Hole’s Human A&P, 12th edition, 2010

14. Male and Female Climacteric
Female climacteric = menopause
usually occurs in late 40s or early 50s (perimenopause)
reproductive cycles stop for 6 months to 1 year
ovaries no longer produce as much estrogen and progesterone due to depletion of ovarian follicles
some female secondary sex characteristics may disappear
sustained rise in GnRH and LH/FSH may produce hot flashes (LH) and fatigue
risk of atherosclerosis increases
hormone therapy may prevent effects on bone tissue
Female climacteric begins when a female has about 1,000 eggs left (rather than at a specific age).
From
Over time, as aging follicles become more resistant to gonadotropin stimulation, circulating FSH and LH levels increase. Elevated FSH and LH levels lead to stromal stimulation of the ovary, with a resultant increase in estrone levels and a decrease in estradiol levels. Inhibins are peptides of the transforming growth factor (TGF)-β superfamily and are produced by the granulosa cells of the ovarian follicles in the terminal stages of development. Inhibin levels also drop during this time because of the negative feedback of elevated FSH levels.[1, 2, 14]
With the commencement of menopause and a loss of functioning follicles, the most significant change in the hormonal profile is the dramatic decrease in circulating estradiol, which rapidly declines over a period of 4 years (starting 2 years before the final menstrual period and stabilizing approximately 2 years after the final period). Without a follicular source, the larger proportion of postmenopausal estrogen is derived from ovarian stromal and adrenal secretion of androstenedione, which is aromatized to estrone in the peripheral circulation.
Total serum testosterone levels do not change during the MT. Dehydroepiandrosterone (DHEAS) levels do decline with age. A trend toward higher total cholesterol, low-density lipoprotein (LDL), and apolipoprotein B levels, in conjunction with loss of the protective effect of high-density lipoprotein (HDL), is characteristic in menopause.[1, 2, 15]
With cessation of ovulation, estrogen production by the aromatization of androgens in the ovarian stroma and estrogen production in extragonadal sites (adipose tissue, muscle, liver, bone, bone marrow, fibroblasts, and hair roots)[15]continue, unopposed by progesterone production by a corpus luteum. Consequently, perimenopausal and menopausal women are often exposed to unopposed estrogen for long periods, and this exposure can lead to endometrial hyperplasia, a precursor of endometrial cancer.
Although estradiol levels decrease significantly because of the loss of follicular production with menopause and postmenopause, estrone, which is aromatized from androstenedione from nonfollicular sources, is still produced and is the major source of circulating estrogen in the postmenopausal female.
Because most conversion of androgens to estrogens occurs in adipose tissue, it is frequently assumed that obese women, who have more circulating estrogen, should have fewer complaints of vasomotor symptoms. However, this is not always the case, and vasomotor symptoms of menopause can be as frequent and severe in heavier women as they are in thinner women.
The clinical indication that menopause has occurred is a rise in the measured FSH level. The FSH level rises more than the LH level because of the reduced renal clearance of FSH in comparison with LH. A slightly elevated or borderline menopausal FSH level in the MT may not be a reliable indicator of menopause, because of the wide variation of FSH and LH levels in response to increased release of gonadotropin-releasing hormone (GnRH) by the hypothalamus and increased pituitary sensitivity to GnRH.
Male climacteric (andropause)
more gradual than female climacteric
usually occurs after age 50
slowly declining levels of testosterone
sperm (gamete) production continues (even into 80s!)

15. Mammary Glands
Mammary glands as shown are for women in last trimester of pregnancy or who are nursing.
The areola, a ring of pigmented skin, covers large sebaceous glands that give it a bumpy appearance. Sebum reduces chapping and cracking of the nipple.
Blood capillaries and nerves come closest to the surface of the skin in the area surrounding the nipple, giving the areola a reddish brown color. Darkening of the areola and nipple during pregnancy help the nursing infant locate the nipple since their vision might not otherwise be able to distinguish this area from the remainder of the breast. Sensory nerve fibers of the areola trigger the milk letdown (ejection) reflex. Bumps on the areola are a result of sebaceous/sweat (areolar) glands in this area. Sebaceous glands help keep the nipple from drying and cracking during nursing.
Figures from: Martini, Anatomy & Physiology, Prentice Hall, 2001

16. Mammary Glands
Figures from: Martini, Anatomy & Physiology, Prentice Hall, 2001
Milk production = lactation
Inactive (resting) mammary gland is dominated by a duct system rather than by active glandular cells. Size of mammary glands in a nonpregnant/nonlactating woman reflects amount of adipose tissue present.

17. Review
inhibits LH and FSH during most of the reproductive cycle
Estrogen is the predominant hormone prior to ovulation (follicular phase)
Progesterone is the predominant hormone after ovulation (luteal phase)
(Day 10)
Estrogen maintains secondary sex characteristics in females
Figure from: Marieb, Anatomy & Physiology, Pearson, 2004

18. Review
Figure from: Hole’s Human A&P, 12th edition, 2010

19. Review Climacteric Women Men Called menopause
Occurs around years of age
Cessation of reproductive cycles – no oocytes
Ovaries no longer produce much estrogen
Men
Occurs more gradually
Sperm production continues well into old age
Levels of testosterone decline gradually