Important announcement!

1. Important announcement! This class now has a Twitter: https://twitter.com/Bio27Laney Go there for: • Links to download lecture slides • Interesting retweets & links

2. chapter 3: female sexual anatomy and physiology

3. Underlying Structures: Pelvic floor muscles • Pelvic floor muscles • Often weakened/damaged by childbirth and with age • Can be strengthened by Kegelexercises

4. Internal female anatomy: the vagina • Three layers of the vagina: • Mucosa on the outside • Muscle layer underneath: muscle thickest and strongest around the vaginal opening • Fibrous tissue (shown in yellow) provides structural support

5. Internal female anatomy • The cervix is at the intersection of the vagina and the uterus • The uterus or (womb) is where a fetus develops and grows • Uterus has 3 layers like the vagina • Innermost layer is called the endometrium; this is what builds up and then sloughs off during menstruation

6. Internal female anatomy • Ovaries: • Release hormones, including estrogens • Produce and release eggs • Fallopian Tubes: • Eggs released from ovaries travel through fallopian tubes to the uterus • Can be the site of ectopic pregnancy

7. Internal female anatomy: the Grafenberg spot • System of glands and ducts that surround the urethra • Anatomically analogous to the male prostate gland • In the front wall of the vagina about 1/3 to ½ way up • “G spot” stimulation is rumored to elicit arousal, orgasm, and female ejaculation; some women do experience enhanced pleasure when this spot is stimulated and others do not

8. Arousal and lubrication • 10-30 sec. after stimulation (may be either physical or psychological), increased blood flow to the vaginal mucosa results in secretion of a clear, slippery fluid • Two functions: • Increases sexual enjoyment; facilitates entry of penis (or whatever) into the vagina • Also changes pH of vaginal canal to make it less acidic; this improves motility and survival of sperm • Artificial lubrication can be used to replace or supplement natural lubrication

9. Other vaginal secretions • Vaginal walls and cervix both normally produce white or yellowish secretions • Appearance, consistency, and odor can vary with a woman’s menstrual cycle • Use of douches and other feminine hygiene sprays can negatively alter the chemical balance of the vagina and cause problems

10. Just add soap & water • Douching can: increase the risk of pelvic inflammatory disease, endometriosis, HIV transmission, ectopic pregnancy, and decreased fertility • Feminine hygiene sprays can cause irritation and infection • Washing the vulva with soap & water is sufficient

11. menstruation

12. Menstruation • Many myths about menstruation and taboos against sexual activity during menstruation • Sloughing off of uterine lining • Menarche is the initial onset of menstruation • Typically happens at age 11–15 • Happens earlier today than it used to; higher body weights may explain this • Proper nutrition is essential for menarche and continued menstruation

13. More about menstruation • Menstrual cycle is defined as the time from the first day of one menstrual period to the start of the next; varies from 24–42 days • Flow usually lasts 2–6 days and total volume is usually 6–8 ounces • Ovulation(release of an egg) usually happens 2 weeks before onset of menstruation

14. Changes During the Menstrual Cycle

15. What Happens During the Menstrual Cycle • The events of the menstrual cycle are controlled by hormones • Hormones are chemical messages released by one part of the body that travel to another part of the body • Master controller of hormones during the menstrual cycle is part of the brain called the hypothalamus • Hypothalamus releases a hormone, GnRHthat stimulates the pituitary gland to release: • Follicle Stimulating Hormone (FSH) • LutenizingHormone (LH) • In men, GnRH, FSH and LH control sperm production

16. What Happens During the Menstrual Cycle • LH and FSH act on the ovary and stimulate the maturation and release of the egg; ovulation is the term for the release of the egg from its casing, called the corpus luteum • The ovaries secrete the hormone estrogen and the corpus luteum secretes progesterone, which stimulate proliferation of the endometrium in preparation for possible pregnancy • If pregnancy does not occur after ovulation, the pituitary gland shuts down release of LH and FSH, leading to a fall in estrogen and progesterone, and the initiation of menstruation

17. Sex and menstruation • Studies of women’s sexual behavior during menstruation have produced conflicting results: some have shown no change in sexual interest, others have shown increased sexual interest • Miller et al. looked at earnings of lap dancers during phases of the menstrual cycle and found that dancers made, on average: • $70/hour during ovulation • $50/hour between ovulation and menstruation • $35/hour during menstruation • Interestingly, dancers taking birth control pills made an average of $37/hour with no cycle fluctuations vs. $53/hour for women not taking the pill

18. Menstrual Cycle Problems • Premenstrual syndrome (PMS) affects 85–90% of women and can cause physical and psychological symptoms such as: • Bloating • Food cravings • Breast swelling • Irritability • Mood swings • Depression • Premenstrual Dysphoric Disorder (PMDD) affects <5% of women and results in more serious psychiatric symptoms that interfere with work or other normal activities • Dysmenorrhea: pain (cramps, nausea, etc.) before or during menstruation • PMS and PMDD have both been linked to the drop in estrogen that occurs before menstruation

19. Treatment of menstrual cycle problems • Many women find that their PMS and dysmenorrhea can be reduced by: • Exercise • Adequate hydration • A low-salt, high-fiber diet • Oral contraceptive use

20. Amenorrhea • Lack of menstruation • Can be due to: • Hormone or other biological abnormalities • A low-calorie diet • Breastfeeding • Prolonged amenorrhea can result in low estrogen levels, which can decrease bone density and contribute to osteoporosis • The oral contraceptive Seasonale allows women to have only four periods a year

21. Menopause • Menopause: the permanent end of menstruation; occurs in late 40s to early 60s • Preceded by perimenopause: irregular periods that may have abnormal bleeding • Hormonal changes associated with menopause can have many other effects, including: • Hot flashes • Decreased vaginal lubrication • Sleep disturbances • Decreased bone density

22. Hormone Therapy in Menopause

23. Gynecological Health Concerns • Urinary tract infections: usually treatable with antibiotics; cranberry juice can suppress symptoms • Vaginal infections: can cause discomfort and discharge; includes bacterial and yeast infections • Pap smear screens for cervical cancer/HPV testing