FORUMS FOR HUMAN SEXUALITY HEALTH
Chapter Three
Female Sexual Anatomy
Female Sex Organs: What Are They for?
- Reproductive function
- Attract partners
- Provide pleasure
- Some anatomical issues remain unresolved
External Structures: The Vulva
- Mons pubis
- Clitoris
- Labia majora
- Labia minora
Mons Pubis
- Latin for pubic mound
- The pad of fatty tissue
- Pubic hair
- Sensitive to stimulation
Clitoris: Glans Clitoris
- Contains a high concentration of nerve endings
- Covered by hood when not engorged
- Erectile
- Sensitive to stimulation
- Structurally analogous to penis
Clitoris
- Erectile internal structure
- Two 3.5” long branches called crura
- Crura contain two corpora cavernosa: hollow chambers that fill with blood and swell during arousal
- Orgasmic
- Enlarges initially, then retracts beneath hood just before and during orgasm
- Follows same pattern with repeated orgasms, though swelling is less pronounced
Labia Majora
- Two folds of spongy flesh extending from the mons pubis toward the perineum
- May have hair present
- Contain a significant concentration of nerve endings
Labia Minora
- Small folds within the labia majora that meet above the clitoris to form the clitoral hood
- Significant variation in appearance
- Contain a significant concentration of nerve endings
- Swell during sexual arousal
- Enclose the vestibule
Internal Structures
- Vagina
- Cervix
- Uterus
- Fallopian tubes
- Ovaries
Vagina
- Two reproductive functions:
- Encompasses penis during coitus (vaginal intercourse)
- Birth canal
- 3” to 5” inches in length
- Introitus: the lower third of the vagina
- The majority vaginal nerve endings
- Hymen: thin membrane that partially covers introitus
- Grafenberg Spot (G-spot)
- An erotically sensitive area on front wall of the vagina mid-way between pubic bone and cervix
- Female ejaculation
Uterus
- Hollow, thick-walled muscular organ
- Accommodates developing fetus during pregnancy
- Approximately 3” by 3” in women who have not given birth
- Endometrium: inner lining
- Menstruation: removal of the endometrium
- Cervix: the tapered end of the uterus, extends and opens into the vagina
Ovaries
- Gonads that produce gametes
- Produce egg cells (oocytes; ova) for reproduction
- Two ovaries; size and shape of large almonds
- Ovaries release oocytes in a process called ovulation
Fallopian Tubes
- Also known as uterine tubes
- Extend toward ovary
- Fimbriae: fingerlike projections that do not connect to the ovary
- Pathway for ovum to reach the uterus
Other Structures
- Urethra: tube through which urine passes
- Urethral opening
- Perineum: area between genitals and anus
- Pelvic floor
Other Structures
- Anus: opening of rectum
- Contains two sphincters (circular muscles that open and close like valves)
- Dense supply of nerve endings
- The lining of the rectum is fragile
- In anal sex play, care must be taken not to rupture the delicate tissues
- Condom and Lubrication
Breasts
- Reproductive function of female breasts is to nourish offspring through lactation
- Composed of fatty tissue and 15-25 lobes that radiate around a central nipple
- Areola: the ring of darkened skin around nipple
- Nipples erect in response to stimulation, cold, or sexual arousal
- Women differ in the breast stimulation they find pleasurable
Female Sexual Physiology:
Reproductive Hormones
- Hormones: chemical substances that serve as messengers
- Sources: Hypothalamus, pituitary gland, ovary
- Gonadotropin releasing hormones are from the hypothalamus and regulate the release of hormones from the pituitary
Pituitary Gonadotropins
- Follicle stimulating hormone (FSH): stimulates the follicle to mature
- Luteinizing hormone (LH): triggers the rupture of the follicle
- Gonadotropins have an effect upon the gonads
Ovarian Hormones
- Estrogens: stimulate maturation of reproductive organs, menstruation, and pregnancy
- Progesterone: helps maintain the uterine lining during pregnancy
Female Sexual Physiology:
Reproductive Hormones
Hormone Where Produced Functions
Estrogen ovaries, adrenal glands Promotes maturation of reproductive
placenta during pregnancy organs, development during puberty,
regulates menstrual cycle, pregnancy
Progesterone ovaries, adrenal glands Promotes breast development, maintains uterine lining, regulates menstrual cycle, sustains pregnancy
Gonadotropin- hypothalamus Promotes maturation of gonads,
Releasing hormone (GnRH) regulates menstrual cycle
Follicle-stimulating pituitary Regulates ovarian function and
hormone (FSH) maturation of ovarian follicles
Female Sexual Physiology: Reproductive Hormones
Hormone Where Produced Functions
Luteinizing pituitary Assists in production of estrogen and
hormone (LH) progesterone, regulates maturation of
ovarian follicles, triggers ovulation
Human chorionic embryo and placenta Helps sustain pregnancy
gonadotropin (HCG)
Testosterone adrenal glands and ovaries Helps stimulate sexual interest
Oxytocin hypothalamus stimulates uterine contractions in
childbirth
Prolactin pituitary stimulates milk production
Prostaglandins all body cells mediate hormone response, stimulate
muscle contractions
The Ovarian Cycle
- Cycle averages 28 days
- Normal cycles last between 21 and 40 days
- Generally results in ovulation in only one ovary per month
- If two eggs are released: Fraternal twins
- Ovaries typically alternate
The Ovarian Cycle
- 3 Phases of the ovary
- Follicular phase: Days 1-10
- Hormones signal 10 to 20 follicles to grow on ovaries; Estrogen matures one oocyte
- Ovulatory phase: Days 11-14
- Oocyte undergoes cell division; Follicle wall thins and ruptures; Oocyte enters abdominal cavity near fimbrae of fallopian tube
- Luteal phase: Days 14-28
- Estrogen levels drop; egg travels through fallopian tube towards uterus
The Menstrual Cycle
- 3 Phases of the uterine cycle
- Menstrual phase (about 3-5 days)
- Endometrium is shed
- Endometrial tissue, mucous, other secretions, and 2-5 oz. blood is expelled through vagina
- Proliferative phase (about 9 days)
- Endometrium thickens, clear thin mucus secreted
- Ends with ovulation
- Secretory phase (14 days)
- endometrium prepares for arrival of fertilized ovum
- If no fertilization, ends with shedding of endometrium
Menstrual products
- Disposable products
- Pads and panty liners
- Tampons
- Reuseable products
- Menstrual cups
- Pads
- Sponges
Menstrual variations
- Emotional, physical, or behavioral changes
- Pre Menstrual Symptoms
- Menstrual dysphoric disorder
- Dysmenorrhea
- Amenorrhea
- Menorrhagia
Sexuality and the Menstrual Cycle
- Research inconclusive between desire and cycle
- Taboo on sex during menstruation
- Societal
- Religious
- Safety and STIs
Sexual response models
- Masters and Johnson
- Kaplan
- Loulan
Female Sexual Response Model
- Masters and Johnson 4 Phase Model:
- excitement
- plateau
- orgasm
- resolution
Female Sexual Response Model
- Kaplan’s Tri-Phasic Model
- Desire
- Excitement
- Orgasm
Female Sexual Response Model
- Loulan’s Sexual Response Model:
- Incorporates biological and affective dimensions
- Willingness
- Desire
- Excitement
- Engorgement
- Orgasm
- Pleasure
Desire: Mind or Matter?
- A complex interaction between
- The neural system
- Hormones
- Occurs throughout many parts of the body
Experiencing Sexual Arousal
- Vasocongestion
- Myotonia
- Vaginal Sweating
- Tenting
- Labia may enlarge or flatten and separate
- Sex flush
- Clitoris swells
- Breathing and heart rate increase
- Nipples become erect, breasts may enlarge
- Uterus elevates
Orgasm
- As excitement increases
- Clitoris retracts beneath clitoral hood
- Vaginal opening decreases by about 1/3
- Orgasmic platform
- Continued stimulation brings orgasm:
- Rhythmic contractions
- Pleasure
Summary
- Female sex organs
- Sexual physiology
- Sexual response