- Ovaries are the primary female reproductive organs
- Make female gametes (ova)
- Secrete female sex hormones (estrogen and progesterone)
- Accessory ducts include uterine tubes, uterus, and vagina
- Internal genitalia - ovaries and the internal ducts
- External genitalia - external sex organs
- The Ovaries
- Paired organs on each side of uterus held in place by several ligaments
- Ovarian - anchors the ovary medially to the uterus
- Broad ligament - contains the suspensory ligament and the mesovarium
- Suspensory - anchors the ovary laterally to the pelvic wall
- Mesovarium - suspends the ovary in between
- They are surrounded by a fibrous tunica albuginea, which is covered by a layer of epithelial cells called the germinal epithelium
- Embedded in the ovary cortex are ovarian follicles
- Each follicle consists of an immature egg called an oocyte
Cells around the oocyte are called:
- Follicle cells (one cell layer thick)
- Granulosa cells (when more than one layer is present)
- Primordial follicle - one layer of squamouslike follicle cells surrounds the oocyte
- Primary follicle - two or more layers of cuboidal granulosa cells enclose the oocyte
- Secondary follicle - has a fluid-filled space between granulosa cells that coalesces to form a central antrum
- Graafian follicle - secondary follicle at its most mature stage that bulges from the surface of the ovary
- Ovulation - ejection of the oocyte from the ripening follicle
- Corpus luteum - ruptured follicle after ovulation
- Uterine Tubes (Fallopian Tubes) and Oviducts
- Receive the ovulated oocyte and provide a site for fertilization
- Empty into the superolateral region of the uterus via the isthmus
- Expand distally around the ovary forming the ampulla
- The ampulla ends in the funnel-shaped, ciliated infundibulum containing fingerlike projections called fimbriae
- The uterine tubes have no contact with the ovaries and the ovulated oocyte is cast into the peritoneal cavity
- Beating cilia on the fimbriae create currents to carry the oocyte into the uterine tube
- The oocyte is carried toward the uterus by peristalsis and ciliary action
- Nonciliated cells keep the oocyte and the sperm nourished and moist
- Uterus
- Hollow, thick-walled organ located in the pelvis anterior to the rectum and posterosuperior to the bladder
- Body - major portion of the uterus
- Fundus - rounded region superior to the entrance of the uterine tubes
- Isthmus - narrowed region between the body and cervix
- Cervix - narrow neck which projects into the vagina inferiorly
- Cervical canal - cavity of the cervix that communicates with:
- The vagina via the external os
- The uterine body via the internal os
- Cervical glands secrete mucus that covers the external os and blocks sperm entry except during midcycle
- Supports of the Uterus
- Mesometrium - portion of the broad ligament that supports the uterus laterally
- Lateral cervical ligaments - extend from the cervix and superior part of the vagina to the lateral walls of the pelvis
- Uterosacral ligament -paired ligaments that secure uterus to sacrum
- Round ligaments - bind the anterior wall to the labia majora
- Uterine Wall - Composed of three layers
- Perimetrium - outermost serous layer; the visceral peritoneum
- Myometrium -interlacing layers of smooth muscle
- Endometrium - mucosal lining
- Has numerous uterine glands; change in length as the endometrial thickness changes
- Stratum functionalis:
- Undergoes cyclic changes in response to ovarian hormones
- Shed during menses
- Stratum basalis:
- Forms a new functionalis after menstruation ends
- Does not respond to ovarian hormones
- Vagina
- Thin-walled tube lying between the bladder and the rectum, extending from the cervix to the exterior of the body
- The urethra is embedded in the anterior wall
- Provides a passageway for birth, menstrual flow, and is the organ of copulation
- Wall consists of three coats: fibroelastic adventitia, smooth muscle muscularis, stratified squamous mucosa
- Mucosa near the vaginal orifice forms an incomplete partition called the hymen
- Vaginal fornix - upper end of the vagina surrounding the cervix
- External Genitalia: Vulva (Pudendum)
- Mons pubis - round, fatty area overlying the pubic symphysis
- Labia majora - elongated, hair-covered, fatty skin folds homologous to the male scrotum
- Labia minora - hair-free skin folds lying within the labia majora; homologous to the ventral penis
- Greater vestibular glands
- Pea-size glands flanking the vagina
- Homologous to the bulbourethral glands
- Keep the vestibule moist and lubricated
- Clitoris (homologous to the penis)
- Erectile tissue hooded by the prepuce
- The exposed portion is called the glans
- Perineum
- Diamond-shaped region between the pubic arch and coccyx
- Bordered by the ischial tuberosities laterally
- Mammary Glands
- Modified sweat glands consisting of 15-25 lobes that radiate around and open at the nipple
- Areola - pigmented skin surrounding the nipple
- Suspensory ligaments attach the breast to underlying muscle fascia
- Lobes contain glandular alveoli that produce milk in lactating women
- Compound alveolar glands pass milk to lactiferous ducts, which open to the outside
- Breast Cancer
- Usually arises from the epithelial cells of the ducts
- Risk factors include:
- Early onset of menses or late menopause
- No pregnancies or the first pregnancy late in life
- Previous history of breast cancer or family history of breast cancer
- Hereditary factors including mutations to the genes BRCA1 and BRCA2
- 70% of women with breast cancer have no known risk factors
- Early detection is by self-examination and mammography
- Treatment depends upon the characteristics of the lesion
- Radiation, chemotherapy, and surgery followed by irradiation and chemotherapy
- Today, lumpectomy is the surgery used rather than radical mastectomy
Female Reproductive Physiology
- Oogenesis
- Production of female sex cells by meiosis
- In the fetal period, oogonia (2n ovarian stem cells) multiply by mitosis and store nutrients
- Primordial follicles appear as oogonia are transformed into primary oocytes
- Primary oocytes begin meiosis but stall in prophase I
- At puberty, one activated primary oocyte produces two haploid cells
- The first polar body
- The secondary oocyte
- The secondary oocyte arrests in metaphase II and is ovulated
- If penetrated by sperm the second oocyte completes meiosis II, yielding:
- One large ovum (the functional gamete)
- A tiny second polar body
- Ovarian Cycle - Monthly series of events associated with the maturation of an egg
- Follicular phase - period of follicle growth (days 1-14)
- The primordial follicle, directed by oocyte, becomes a primary follicle
- Primary follicle becomes a secondary follicle
- Theca folliculi and granulosa cells cooperate to produce estrogens
- The zona pellucida forms around the oocyte
- The antrum is formed
- The secondary follicle becomes a vesicular follicle
- The antrum expands and isolates the oocyte and the corona radiata
- The full size follicle (vesicular follicle) bulges from the external surface of the ovary
- The primary oocyte completes meiosis I, stage is set for ovulation
- Ovulation
- Ovulation occurs when the ovary wall ruptures and expels the secondary oocyte
- Mittelschmerz - a twinge of pain sometimes felt at ovulation
- Luteal Phase
- After ovulation, the ruptured follicle collapses, granulosa cells enlarge, and along with internal thecal cells, form the corpus luteum
- The corpus luteum secretes progesterone and estrogen
- If pregnancy does not occur, the corpus luteum degenerates in 10 days, leaving a scar (corpus albicans)
- If pregnancy does occur, the corpus luteum produces hormones until the placenta takes over that role (at about 3 months)
- Establishing the Ovarian Cycle
- During childhood, ovaries grow and secrete small amounts of estrogens that inhibit the hypothalamic release of GnRH
- As puberty nears, GnRH is released; FSH and LH are released by the pituitary, which act on the ovaries
- These events continue until an adult cyclic pattern is achieved and menarche occurs
- Hormonal Interactions During the Ovarian Cycle
- Day 1 - GnRH stimulates the release of FSH and LH
- FSH and LH stimulate follicle growth and maturation, and low-level estrogen release
- Rising estrogen levels:
- Inhibit the release of FSH and LH
- Prod pituitary to synthesize and accumulate these gonadotropins
- Estrogen levels increase and high estrogen levels have a positive feedback effect on the pituitary, causing a sudden surge of LH
- The LH spike stimulates the primary oocyte to complete meiosis I, and the secondary oocyte continues on to metaphase II
- Day 14 - LH triggers ovulation
- LH transforms the ruptured follicle into a corpus luteum, which produces inhibin, progesterone, and estrogen
- These hormones shut off FSH and LH release and declining LH ends luteal activity
- Days 26-28 - decline of the ovarian hormones
- Ends the blockade of FSH and LH
- The cycle starts anew
- Uterine (Menstrual) Cycle
- Series of cyclic changes that the uterine endometrium goes through each month in response to ovarian hormones in the blood
- Days 1-5: Menstrual phase - uterus sheds all but the deepest part of the endometrium
- Days 6-14: Proliferative (preovulatory) phase - endometrium rebuilds itself
- Days 15-28: Secretory (postovulatory) phase - endometrium prepares for implantation of the embryo
- Menses
- If fertilization does not occur, progesterone levels fall, depriving the endometrium of hormonal support
- Spiral arteries kink and go into spasms and endometrial cells begin to die
- The functional layer begins to digest itself
- Spiral arteries constrict one final time then suddenly relax and open wide
- The rush of blood fragments weakened capillary beds and the functional layer sloughs
- Extrauterine Effects of Estrogens and Progesterone
- Estrogen levels rise during puberty
- Promote oogenesis and follicle growth in the ovary
- Exert anabolic effects on the female reproductive tract
- Uterine tubes, uterus, and vagina grow larger and become functional
- Uterine tubes and uterus exhibit enhanced motility
- Vaginal mucosa thickens and external genitalia mature
- Estrogen-Induced Secondary Sex Characteristics
- Growth of the breasts
- Increased deposition of subcutaneous fat, especially in the hips and breasts
- Widening and lightening of the pelvis
- Growth of axillary and pubic hair
- Female Sexual Response
- The clitoris, vaginal mucosa, and breasts engorge with blood
- Activity of vestibular glands lubricates the vestibule and facilitates entry of the penis
- Orgasm - accompanied by muscle tension, increase in pulse rate and blood pressure, and rhythmical contractions of the uterus
- Females do not have a refractory period after orgasm and can experience multiple orgasms in a single sexual experience
- Orgasm is not essential for conception
- Menopause
- Ovulation and menses cease entirely
- Without sufficient estrogen, reproductive organs and breasts atrophy
- Irritability and depression result
- Skin blood vessels undergo intense vasodilation (hot flashes occur)
- Gradual thinning of the skin and bone loss
- Males have no equivalent to menopause
- Gonorrhea
- Bacterial infection spread by contact with genital, anal, and pharyngeal mucosal surfaces
- In males - painful urination, discharge of pus from the penis
- In females - none (20%), abdominal discomfort, vaginal discharge, abnormal uterine bleeding
- Left untreated, can result in pelvic inflammatory disease
- Treatment: antibiotics, but resistant strains are becoming more prevalent
- Syphilis
- Bacterial infection transmitted sexually or contracted congenitally
- Infected fetuses are stillborn or die shortly after birth
- A painless chancre appears at the site of infection and disappears in a few weeks
- Secondary syphilis shows signs of pink skin rash, fever, joint pain
- A latent period follows, which may progress to tertiary syphilis characterized by gummas (lesions of the CNS, blood vessels, bones, and skin)
- Treatment: penicillin
- Chlamydia - Most common STD in the U.S.
- Responsible for 25-50% of all diagnosed cases of pelvic inflammatory disease
- Symptoms include urethritis; penile and vaginal discharges; abdominal, rectal, or testicular pain; painful intercourse; irregular menses
- Can cause arthritis & urinary tract infections in men, sterility in women
- Treatment is with tetracycline
- Viral Infections
- Genital warts- caused by human papillomaviruses (HPV); infections increase the risk of penile, vaginal, anal, and cervical cancers
- Genital herpes - caused by Epstein-Barr virus type 2 and characterized by latent periods and flare-ups
- Congenital herpes can cause malformations of a fetus
- Has been implicated with cervical cancer
- Treatment: acyclovir and other antiviral drugs
Forward comments to RM Chute .....
Home Page ....
Updated: