Female Hormones and the Menstrual Cycle

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Female Hormones and the Menstrual Cycle

• JP Slovak

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Sex Hormones

• Ovaries, adrenal cortex and placenta secrete
• Estrogen and progesterone
• Estrogen functions
• Enlargement of reproductive structures
• Breast enlargement
• Increase in adipose tissue
• Increased vascularization of skin
• Female shape low levels of androgens

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Reproductive Cycle

• Humans, apes , old world monkeys menstrual
  cycle
• Periodic shedding of endometrium
• Bleeding accompanies shedding
• Estrus
• No bleeding in most other mammals

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Menstrual Cycle

• 28 days
• Ovarian
• Flow day 1
• Day 1 to ovulation follicular phase
• Ovulation day 1 luteal phase
• Endometrium
• Menstrual, proliferative, secretory

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Follicular Phase

• Menstruation day 1 to 4 or 5
• Ovarian steroids low during menstruation
• Ovaries have primary follicles
• Eventually become secondary follicles
• Towards end, one becomes a Graafian follicle
• Granulosa cells secrete estradiol
• FSH growth of follicle growth of receptors
• Follicles become sensitive
• Toward end, FSH and estradiol increase LH
  receptors on Graafian follicle

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Follicular Phase

• Rise in estradiol
• Makes pituitary more sensitive to GnRH
• Late follicular phase increase in LH
• LH surge is 24 hours before ovulation

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ovulation

• FSH- Graafian follicle becomes a blister
• Rise in estradiol triggers LH surge
• LH surge cause follicles to release oocyte
• Arrested at metaphase II
• Follicle sets the time for its own ovulation

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Luteal Phase

• Corpus luteum
• Secretes estradiol and progesterone
• Pro peaks during luteal phase
• Pro and estradiol neg feedback on FSH and LH
• Retards development of new follicles
• Pro and estradiol fall in late luteal phase
• Luteolysis
• Corpus luteum brings about its own demise.

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Menstrual Problems

• Pre menstrual syndrome
• 70 90 percent experience some difficulty
• Normally 3 10 days prior to menstruation
• Cramps, backaches, dizziness
• Fatigue, deprssion, anxiety
• Possible causes
• Hormonal, nutrition, psychologic
• Treatment
• Restrict salt and water intake
• Exercise
• Progesterone therapy
• diuretics

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Menstrual Problems

• Dysmenorrhea
• Pain during menstruation
• Severe contractions of uterus
• PG may be cause(aspirin treatment)
• Primary
• PG induced
• Secondary
• Caused by tumors, endometriosis, infection
• Smoking can increase

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Menstrual Problems

• Amenorrhea
• Primary no menstruation by 16
• Anorexia
• Low body fat
• 22 BF for cycle to continue?
• 10 15 percent wieght loss can induce
• Exercise lowers LH(endorphins)
• 1/3 of estrogen in blood comes from adipose
  tissue
• Oligomenorrhea
• Secondary Amenorrhea
• Failure to menstruate for six months

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Menstrual Problems

• Menopause
• Symptoms
• Dizziness, numbness, insomnia
• Hot flashes (1/4 of women)
• Shrinking of external genetalia, breasts , uterus
• Ca and P lost at a higher rate
• Women may still ovulate
• Use BC for a year after menstruation stops
• Causes
• GnRH secretion pattern changes
• Ovaries nonrespondent to FSH and LH
• Most germ cells are gone
• Ovaries degenerate
• Adrenal Glands continue to secrete androgens

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Menstrual Problems

• Menopause treatment
• 30 to 50 take ERT
• If continued for 7 years, decreased risk of
  osteoporosis
• 30K women die from fractures (1.3m total
  fractures)
• Set back ERT for greater than 5 years leads to
  greater chance of breast cancer
• No effect for less than 5 years
• ERT and endometrial cancer increase
• Progesterone
• Induces mitosis of mammary glands
• Inhibits endometrial mitosis