Lecture 8: Female Reproductive System

Viral STIs

*HPV* warts appear on penis, perineum or anus in men....and on cervix, vaginal wall, perineum or anus in females. if mother has genital warts in late pregnancy, newborn can get them in throat (rare). Several strains of HPV increase risk of developing cervical cancer *Genital herpes* individuals may be asymptomatic or have extremely painful blisters on external genitalia, thighs or buttocks. Disease is spread with contact to open sores. Can be passed to newborns causing neonatal herpes, which can be fatal

hormones involved in follicle maturtion - feedback loops

*Thecal cells* produce ANGROGEN which will be converted into ESTRADIOL/ESTROGEN which is endogenous estrogen...this conversion occurs thanks to the enzyme produced by the *granulosa cells* called "aromatase" ESTROGEN stimulates pituitary gland to suppress FSH, so all the small follicles that depend on this die and the 1 cell remains. ESTROGEN also acts on functional layer endometrium to proliferate

vulva anatomy

*mons pubis*: fatty, rounded region overlaying pubic symphysis; covered with hair after puberty *labia majora*: pair of elongated fatty protective skin folds that lie posterior to mons pubis *hymen* is a vascular partition of mucosa near vaginal opening which is commonly ruptured during first sexual intercourse

uterine tube anatomy

*peritoneum* - outer covering *isthmus* - constricted region that connects the tube to uterus *ampulla* - wider portion of the tube before reaching the infundibulum *infundibulum* - funnel shaped end of the uterine tube that connects to ovary *fimbriae* - finger like ciliated projections that extend from edges of infundibulum

ovarian anatomy

*tunica albuginea* fibrous layer that surrounds ovaries *ovarian cortex* outer region. oogenesis occurs here *ovarian medulla* inner region where blood vessels, lymphatic vessels and nerves are found *follicles* are found in medulla. they contain oocytes

vagina anatomy

*vaginal fornix* innermost end of vaginal canal that surrounds the external os of cervix (cervix portion that hangs down) vaginal wall is lined with transverse ridges called *rugae* which stimulate the penis during intercourse *vaginal mucosa* is composed of stratified squamous epithelium that can withstand frictional forces during sex; mucus from cervix provides lubrication - epithelial cells secrete glycogen in vaginal lumen which is metabolized by resident bacteria. this in turn generates lactic acid that helps maintain acidic pH of vagina. This acidic environment allows *no bacteria* (including sperm) to get into the cervix

ovarian hormones

- estradiol - estrone - estriol - progesterone - inhibin - relaxin

first menstral cycle

1st cycle begins 70-90 days before the actual bleeding begins

Menstrual cycle--ovarian phase

Day 1-14 FOLLICULAR PHASE Primary follicles become secondary with the help of GnRH (from hypothalamus) and LH/FSH (from anterior pituitary) Secondary follicle has granulosa cells (secrete enzyme) AND thecal cells (secrete androgen) androgen --> estradiol aka Estrogen (via aromatase) Tertiary follicle (aka graafian follicle or antral follicle) has increased production of estrogen LUITINE PHASE Increased production of hormones causes rupture of follicle, releasing of oocyte, and formation of corpus lutium (releases progesterone, estrogen, inhibin) meanwhile.....estrogen is forming the endometrial layer in the uterus

hormone relay

HYPOTHALAMUS releases *GnRH* (gonadotrophin-releasing hormone) which acts on ANTERIOR PITUITARY GLAND to release *FSH* (follicle stimulating hormone) and *LH* (leutinizng hormone)

INTERNAL ORGANS

UTERUS UTERINE TUBES - connect ovaries to uterus OVARIES - two of them VAGINA - vaginal canal uterus is held in body by *suspensory ligaments*

clitoris

anterior to vestibule; small protusion composed of erectile tissue - when stimulated, erectile tissue becomes engorged with blood - tissue is innervated with sensory, motor and autonomic fibers as well as tactile, pressure and temperature receptors...all of which are important for sexual stimulation

Bacterial and parasitic STIs

caused by pathogenic bacteria and parasites that invade tissues and cause an inflammatory response *chlamydia* is typically asymptomatic. if untreated can cause pelvic inflammatory disease (PID) and block the fallopian tubes....leading to infertility. newborns become infected in the birth canal; can result in respiratory tract infections and a form of conjunctivitis that can cause blindness *gonorrhea*, women are typically asymptomatic. if left untreated can lead to PID and blindness in newborns *syphilis* causes a small painless lesion called a chancre (which is contagious). if untreated can enter latent stage *trichomoniasis* may cause itching, burning or redness in genitals; white to greenish discharge in women w/ strong odor. disease can be asymptomatic. infection during pregnancy can lead to premature birth weight and low birth weight

perineum

diamond shaped region located between pubic arch, coccyx, and ischial tuberosities *episiotomy* surgical incision made in perineum during childbirth to prevent natural tearing, as tearing is more difficult to heal

oocytes

eggs that have not developed yet we start off with 7 mil before we are even born...which goes down to 1 mil in each ovary at our birth. In our fertile years we have secrete 400-500 eggs

oogenesis BEFORE BIRTH

female stem cells called *oogonia* complete their mitotic division between 3rd and 7th month of fetal development...then called *primary oocytes* progress to prophase I before their development is arrested

uterine tubes

form initial segment of reproductive system - extend from ovary to uterus

minor ligaments

found in purple on the image; mostly help hold the uterus in place *uterosacral ligament*: connects uterus to sacrum posteriorly *lateral cervical ligament*: extends from cervix and superior vagina to wall of pelvis *round ligament*: connects uterus to anterior body

major ligaments

hold the female reproductive organs in their place. found in red on picture *suspensory ligament*: thicker tube like ligament, contains ovarian vessels (artery, vein and nerve) *broad ligament*: more of a meshy ligament with multiple parts that attaches ovaries, uterine tubes and uterus to the body pelvis *ovarian ligament*: tube which connects ovaries to the uterus (near the uterine tube)

BIRTH CONTROL

hormonal methods contain synthetic estrogens and progesterone which inhibit the release of FSH and LH (tricks body into thinking its pregnant) non hormonal methods such as an IUD, emit copper which poisons ovum and sperm

MAMMARY GLANDS

modified sweat glands; part of integumentary system; produce milk for newborn infant Each gland: - is found within the hypodermis and enclosed within a rounded, skin-covered breast - is composed of 15-25 lobes that radiate around and open into nipple; they are supported by fibrous connective tissue, fat and suspensory ligaments Each lobe: - is subdivided into smaller lobules which contain grandular alveoli (produce milk when a women is lactating) surrounded by myoepithelial cells (surround alveoli in breast and help propel milk towards nipple) *areola* is the hyperpigmented region surrounding each nipple

Menstrual cycle--uterine phase

ovum taken by fallopian tube travels to ampillary region where fertilization typically occurs (or may not occur) ovum then passes into uterine cavity. Corpus lutium will have produced estrogen that will start endometrial lining of the uterus. The progesterone will form the endometrial glands that allow the ovum to be implanted Endometrium will start shedding 0-4 days. PROLIFERATION PHASE - thanks to estrogen, uterus walls gain endometrium SECRETORY PHASE - endometrial glands secrete mucus for ovum MENSTRUATION - bleeding

labia minora anatomy

pair of thinner skin folds found enclosed within labia majora *vestibule*: recess enclosed within labia minor; contains urethral orifice and vaginal orifice *paraurethral glands*: in vestibule; discharge mucus into urethra *Bartholin's glands*: secrete mucus into vestibule during intercourse

ovaries

paired female gonads found on lateral walls of pelvic cavity produce: ova ovarian arteries and ovarian branch of uterine artery supply blood to this organ

uterus

pear shaped hollow organ where the baby grows three parts - body - fundus (round top region) - cervix

uterus anatomy

uterine wall is composed of three layers: 1) Perimetrium - outermost layer; serous 2) Myometrium - middle layer composed of smooth muscle; contracts during orgasm and childbirth 3) Endometrium - innermost layer; composed of simple columnar epithelium; forms a mucous membrane that rests on a thin layer of connective tissue called *lamina propria* - has a basal layer (contains stem cells) and a functional layer (which sheds off during menstruation) Also have the cervix

Cervical cancer

Cervical cancer occurs most often in women between the ages of 30 and 50, particularly those with a history of sexually transmitted infections, cervical inflammation, or multiple pregnancies Frequently caused by human papillomavirus (HPV), which is transmitted sexually Cervical cancer used to be a leading cause of cancer death for women in United States; in past few decades, both number of cases and number of deaths from cervical cancer have decreased significantly; projected to decrease further as HPV vaccine becomes more widespread

flow of milk from breast

Milk passes from *alveoli* into series of *mammary ducts*, which flow into *lactiferous ducts* that open into nipple deep to areola, each lactiferous duct has a dilated region called *lactiferous sinus* where milk accumulated during nursing glandular structure of breast is mostly underdeveloped in women who are not pregnant

EXTERNAL ORGANS

VULVA

follicle maturation

primordial follicles--> primary follicles--> secondary follicles--> tertiary follicles *primordial follicles* contain one oocyte. from birth until puberty they are becoming *primary follicles* which are lined with "granulosa cells" that surround the oocyte 70-90 days before menarche, the 30-50 primary follicles get a lot bigger and gain another cell layer called "thecal cells". Then 1 out of those 30-50 becomes the biggest/dominant and becomes the *secondary follicle* which contains the oocyte (with 46 chromosomes that has not undergone miosis) ESTROGEN is responsible for conversion to *tertiary follicle* which will be similar to secondary except contain a sac called ANTRUM which is filled with fluid (made by granulosa cells) that will help nourish the oocyte. Tertiary follicle is also situated in the ovarian cortex (half in and out of the ovary) The oocyte then divides and has 23 chromosomes. When estrogen levels reach about 200 they will upregulate FSH and LH which will rupture the follicle and allow the oocyte to travel into the fallopian tubes....where it is to meet the sperm. Ruptures follicle becomes *corpus luteum* which secretes hormones ESTROGEN will also stimulate functional layer of endometrium in uterus to proliferate AND it will decrease the acidity of the secretions surrounding the cervix which allows the sperm to enter the cervix and uterus this window is 11-15 days after menstrual cycle begins. this is when the sperm can fertilize the egg

oogenesis

production of female gametes (ova) process begins before female infant is even born, then put on HOLD until puberty. it is then active until *menopause* between 45-55 years of age occurs in follicles of ovaries once per month

vagina

receives penis and semen during sex, passageway for giving birth and for menstrual flow thick-walled tube that extends from cervix to vaginal opening

STI's

sexually transmitted infections can cause infertility in adults and deformities or possibly death of fetuses

oogenesis DURING PUBERTY

specific hormone levels trigger initiation of ovarian cycle

Fertilization

sperm must meet oocyte in the fallopian tube in that 11-15 day window. if it does, becomes a zygote and then takes 3 days to travel down fallopian tube to uterus where it is free floating On the 4th day, after it has entered the uterine cavity, the zygote will divide

corpus luteum

tertiary follicle becomes this after releasing oocyte secretes 3 hormones Thica cells --> progesterone & estrogen & inhibin (which inhibit pituitary gland and hypothalamus from releaseing FSH, LH, and GnRH to stop ovulation....since assumed pregnant Progesterone will help to develop the endometrial glands which are in the wall of the uterus and secrete nutrient rich mucus which allow the egg to survive until the placenta develops all this happens in the 3rd week of menstruation....however if there is no conception, the corpus luteum will gradually degenerate and remain as a small whiteish scar on the ovarian cortex....resulting in less progesterone and less estrogen release, which can cause PMS and also kills the top layer of the endometrium so it sheds off