The organs of the female reproductive system include
- 1. The ovaries-produce secondary oocytes and hormones, including progesterone and estrogen (female sex hormones), inhibin and relaxin
- 2. The uterine tubes-transport a secondary oocyte to the uterus and normally are the sites where fertilization occurs.
- 3. The uterus is the site of implantation of a fertilized ovum, development of the fetus during pregnancy, and labor.
- 4. The vagina receives the penis during sexual intercourse and is a passageway for childbirth
- 5. The mammary glands synthesize, secrete, and eject milk for nourishment of the newborn
the ovary is female gonads, pair of organs, size of unshelled almonds found in upper pelvic region
- gametes, secondary oocytes that develop into mature ova (eggs) after fertilization
- hormones including progesterone and estrogen, inhibin and relaxin
series ligament holds ovaries in position
Broad ligament of the uterus which is part of the parietal peritoneum, attaches to the ovaries by a double-layered fold of peritoneum called the mesovarium. The ovarian ligament anchors the ovaries to the uterus, and suspensory ligaments attaches them to the pelvic wall. Suspensory ligament covers blood vessels to ovaries. Round ligament extends from uterus to labia majora
Histology of the ovary
- Germinal epithelium is a layer of simple epithelium that covers the surface of the ovary
- Tunica albuginea is a whitish capsule of dense irregular connective tissue located immediately deep to the germinal epithelium
- Ovarian cortex is a region just deep to the tunica albuginea. It consist of ovarian follicles
- Ovarian medulla is deep to the ovarian cortex. Composed of connective tissue, blood vessels & lymphatics
Ovarian follicels are in the cortex and consist of oocytes in various stages of development
When the surrounding cells (primordial follicle) form a single layer, they are called follicular cells; later in the development, when they form several layers, they are referred to as granulose cells. The surrounding cells nourish the developing oocyte and begin to secrete estrogen as the follicle grows later.
Mature (graafian) follicle
Mature (graafian) follicle is a larger, fluid filled follicle that is ready to rupture and expel its secondary oocyte, a process known as ovulation
A corpus luteum contains the remnants of a mature follicle after ovulation. The corpus luteum produces progesterone, estrogen, relaxin, and inhibin until it generates into fibrous scar tissue called the corpus albicans.
The formation of gametes in the ovaries is termed oogenesis.In contract to spermatogenesis, which begins in males at puberty, oogenesis begins in females before they are even born.During early fetal development, primordial germ cells migrate from the yolk sac to the ovaries. There, germ cells differentiate within the ovaries into oogonia. Oogonia are diploid (2n) stem cells that divide mitotically to produce millions of germ cells. Even before birth, most of these cells germ cells degenerate in a process known as atresia. A few develop into larger cells called primary oocytes that enter prophase of meiosis I during fetal development but don’t complete that phase until after puberty. During this stage of development, each primary oocyte is surrounded by a single layer of flat follicular cells, and the entire structure is called a primordial follicle. The ovarian cortex surrounding the primordial follicles consist of collagen fibers and stromal cells.
A few primordial follicles start to grow, developing into primary follicles. Each primary follicle consists of a primary oocyte that is surrounded by granulosa cells. As the primary follicle grows it forms a clear glycoprotein layer called the zona pellucida between the primary oocyte and the granulose cells. In addition, stromal cells surrounding the basement membrane begin to form an organized layer called the theca follicului.
A primary follicle develops into a secondary follicle. In a secondary follicle, the theca differentiates into two layers: Theca interna –highly vascularized that secrete estrogen,Theca externa, an outer layer of stromal cells and collagen fibers
The granulose cells begin to secrete follicular fluid, which builds up in a cavity called the antrum in the center of the secondary follicle
The innermost layer of granulose cells becomes firmly attached to the zona pellucid and is now called the corona radiate.
mature (graafian) follicle
The secondary follicle eventually becomes larger, turning into a mature (graafian) follicle. Just before ovulation, the diploid primary oocyte completes meiosis I, producing two haploid cells (n) of unequal size-each with 23 chromosomes.1) The smaller cells produces by meiosis I called the first polar body. 2) The larger cell known as the secondary oocyte. Once secondary oocyte is formed, it begins meiosis II but then stops in metaphase. The mature ( graafian) follicle soon ruptures and releases its secondary oocyte, a process known as ovulation.
Zona pellucida -- clear area between oocyte & granulosa cells
Corona radiata is granulosa cells attached to zona pellucida--still attached to oocyte at ovulation
Stages of follicular development
Females have two uterine tubes (fallopian), or oviducts, 4 inch tube extends from ovary to uterus.They provide a route for sperm to reach an ovum and transport secondary oocytes and fertilized ova from the ovaries to the uterus. Infundibulum is open, funnel-shaped portion near the ovary. It ends in a fringlelike projections called fimbriae, one of which is attached to the lateral end of the ovary, ampulla is central region of tube, isthmus is narrowest portion joins uterus.
Histology Uterine Tube
Mucosa-ciliated columnar epithelium with simple columnar cells, which help move a fertilized ovum within the uterine tube toward the uterus, and nonciliated cells called peg cell, which have microvilli and secrete a fluid that provides nutrition for the ovum. Muscularis-is composed of an inner circular ring of smooth muscle and outer longitudinal smooth muscle. Peristaltic contraction of the muscularis and the ciliary action of the mucosa help move the oocyte or fertilized ovum toward the uterus. Serosa-outer serous membrane
Function of Uterine Tube
Fimbriae sweep oocyte into tube; peristalsis moves oocyte along tube; sperm reaches oocyte in ampulla; fertilization occurs within 24 hours after ovulation; zygote reaches uterus about 7 days after ovulation
The uterus (womb) serves as part of the pathway for sperm deposited in the vagina to reach the uterine tubes. It also the site of implantation of a fertilized ovum, development of the fetus during pregnancy, and labor. During reproductive cycles when implantation does not ocur, the uterus is the source of menstrual flow.
Anatomy of the Uterus
3 inches long by 2 in wide and 1 in. thick. Subdivided into fundus, body, isthmus and cervix. Interior of the cervix is called the cervical canal. The cervical canal opens into the uterine cavity at the internal os and into vagina at the external os. Normally, the body of the uterus projects anteriorly and superiorly over the urinary bladder in a position called anteflexion. Retroflexion -- posterior tilting of the uterus
Histology of the uterus
Histologically, the uterus consist of three layers of tissue: 1) perimetrium--outer layer; it composed of simple squamous epithelium. 2) myometrium--consist of three layers of smooth muscle fibers. The inner and outer longitudinal, the middle is circular. 3) endometrium--Innermost layer composed of simple columnar cells epithelium (ciliated and secretory cells) lines lumen, highly vascularized. An underlying endometrial stroma is a very thick region of lamina propria.The endometrium is divided into two layers: Stratum functionalis that shed during menstruation, and stratum basalis taht is permanent and gives rise to a new stratum functionalis after each menstruation
Hysterectomy is a surgical removal of the uterus. Indications for surgery: endometriosis, ovarian cysts, excessive bleeding, cancer of cervix, uterus or ovaries. Partial hysterectomy removes the body of the uterus but the cervix is left. Complete hysterectomy removes both the body and the cervix of the uterus. Radical hysterectomy removes uterus, tubes, ovaries, part of vagina, pelvic lymph nodes and supporting ligaments.
The secretor cells of the mucous of the cervix produce a secretion called cervical mucus, a mixture of water, glycoproreins, lipids, enzymes, and inorganic salts.
Passageway for birth, menstrual flow and intercourse. 4 inch long fibromuscular organ ending at cervix. Lies between urinary bladder and rectum. Orifice partially closed with membrane (hymen).
Histology of vagina
- Mucosal layer--stratified squamous epithelium and areolar connective tissue that lies in a series of transverse folds called rugae. Large stores of glycogen, the decomposition of which produces organic acids. the resulting acidic environment retards microbial growth, but it also is harmful to sperm. Alkaline components of semen, mainly from the seminal vesicles, raise the pH of fluid in the vagina and increase viability of the sperm
- muscularis layer--is smooth muscle allows considerable stretch to accommodate the penis during sexual intercourse and a child birth
- Adventitia--is superficial loose connective tissue that binds it to other organs such as the urethra and urinary bladder, rectum and anal canal
The term vulva or pudendum refers to external genitals of the female. Mons pubis -- fatty pad over the pubic symphysis. Labia majora and labia minora -- folds of skin encircling vestibule where find urethral and vaginal openings. Clitoris -- small mass of erectile tissue
The vaginal orifice, the opening of the vagina to the exterior
external urethral orifice
External urethral orifice is the opening of the urethra to the exterior.
Perineum is a diamond-shaped area between the thighs in both sexes. Bounded by pubic symphysis and coccyx. Urogenital triangle contains external genitals. Anal triangle contains anus
vestibular (Bartholin’s) glands
On either side of the vaginal orifice are the greater vestibular (Bartholin’s) glands. They produce a small quantity of mucus during sexual arousal and intercourse that adds to cervical mucus and provides lubrication.
bulb of the vestibule
The bulb of the vestibule consists of two elongated masses of erectile tissue deep to the labia on either side of the vaginal orifice. The bulb of the vestibule becomes engorged with blood during sexual arousal, narrowing the vaginal orifice and placing pressure on the penis during intercourse.
Homologous Structures; Female & Male Reproductive Systems
· ovaries – testes
- · ovum - sperm cell
- · labia majora – scrotum
- · labia minora – spongy (penile) urethra
- · vestibule – membranous urethra
- · clitoris – glans penis
- · paraurethral glands – prostate
- · greater vestibular glands – bulbourethral glands
paraurethral (Skene’s glands)
On either side of the external urethra orifice are the openings of the ducts of the paraurethral (Skene’s glands).
Within each breast is a mammary gland, a modified sudoriferous (sweat) gland that produces milk. A mammary gland consists of 15-20 lobes, or compartments, separated by a variable amount of adipose tissue. Lactiferous duct where milk emerges. The circular pigmented area of skin surrounding the nipple is called the areola. In each lobe are several smaller compartments called lobules, composed of grapelike cluster of milk-secreting glands termed alveoli embedded in connective tissue. Contraction of myoepithelial cells surrounding the alveoli helps propel milk toward the nipples.
The function of the mammary glands is the synthesis, secretion, and ejection of milk; these function is called lactation, are associated with pregnancy and childbirth.
lactiferous sinuses near the nipple is where some milk may stored before draining into a lactiferous duct.
Milk production is stimulated largely by the hormone prolactin from anterior pituitary, with contributions from progesterone and estrogen.
The ejection of milk is stimulated by oxytocin, which is released from the posterior pituitary in response to sucking of an infant on the mother’s nipple.
Fibrocystic Disease of the Breasts
In Fibrocystic Disease of the Breasts, the most common cause of breast lumps in females, one or more cysts (fluid filled sacs) and thickenings of alveoli develop. Cause is hormonal imbalance
Female Reproductive Cycle
During the reproductive years, nonpregnant females normally exhibit cyclical changes in the ovaries and uterus. Monthly cycle of changes in ovary and uterus. Involves oogenesis and preparation of the uterus to receive a fertilized ovum. Monthly hormone cycle of controlled by hypothalamus , anterior pituitary, & ovary. The ovarian cycle is a series of events in the ovaries that occur during and after the maturation of an oocyte. The uterine (menstrual) cycle is a concurrent series of changes in the endometrium of the uterus to prepare it for the arrival of a fertilized ovum that will develop there until birth. if implantation does not occur, the stratum functionalis is shed during menstruation
Gonadotropin-releasing hormone (GnRH)
Gonadotropin-releasing hormone (GnRH) secreted by the hypothalamus controls the female reproductive cycle. Stimulates anterior pituitary gland to secrete Follicle-stimulating hormone (FSH) and luteinizing hormone (LH).
Follicle-stimulating hormone (FSH)
FSH initiates follicular growth
luteinizing hormone (LH).
LH stimulates further development of the ovarian follicles. LH stimulates the theca cells of a developing follicle to produce androgen. Under the influence of FSH, the androgen are taken up by the granulose cells of the follicle and then converted into estrogen. At midcycle, LH triggers ovulation and then promotes formation of the corpus luteum. The corpus luteum produces and secretes estrogen, progesterone, relaxin, and inhibin.
Estrogen promotes the development and maintenance of female reproductive structures, secondary sex characteristics, and the breast, increase protein anabolism, lower blood cholesterol level; moderate levels of estrogens in the blood inhibit both the release of GnRH by the hypothalamus and secretion of LH and FSH by the anterior pituitary.
Progesterone, secreted mainly by cells of the corpus luteum, prepares uterus for implantation and the mammary glands for milk secretion. High levels of progesterone also inhibit secretion of GnRH and LH
Relaxin produced by the corpus luteum during each monthly cycle relaxes the uterus by inhibiting contractions of the myometrium. During pregnancy, the placenta produces much more relaxin, and it continues to relax uterine smooth muscle. At the end of pregnancy, relaxin also increases the flexibility of the pubic symphysis and may help dilate the uterine cervix, both of which ease delivery of the baby.
inhibin is secreted by granulose cells of growing follicles and by the corpus luteum after ovulation. It inhibits secretion of FSH.
Phases of the female reproductive cycle
- The duration of the female reproductive cycle typically ranges from 24 to 35 days. Average 28 days. Divide into 4 phases
- 1. menstrual phase
- 2. preovulatory phase
- 3. ovulation
- 4. postovulatory phase
- Events in oven: Under the influence of FSH, several primordial follicles develop into primary follicles and then into seconadary follicles. This development may take several moth to occur. Therefore, a follicle that begins to develop at the beginning of a particular menstrual cycle may not reach maturity and ovulate untill several menstrual cycles later.
- Events in the Uterus: Menstrual flow from the uterus consist of 50-150 mL of blood, tissue fluid, mucus, and epithelial shed from the endometrium. Declining levels of progesterone caused spiral arteries to constrict and cause glandular tissue dies. Eventually, the entire stratum functionalis slough off. At this time the endometrium is very thin, about 2-5 mm, because only the basalis remains. The menstrual flow passes from the uterine cavity through the cervix and vagina to the exterior.
- events in the ovary: By about 6 day, a single secondary follicle in one of the two ovaries has outgrown all the others to become the dominant follicle. Estrogen and inhibin secreted by the dominant follicle decrease the secretion of FSH, which cause other, less well-developed follicles to stop growing and undergo atresia. By day 14, graafian follicle has enlarged & bulges at surface. During the final maturation process, the mature follicle continues to increase its production of estrogen. With reference to the ovarian cycle, the menstrual and preovulatory phases together are termed the follicular phase because ovarian follicle are growing and developing.
- Events in the uterus: Increasing estrogen levels have repaired and thickened the stratum functionalis to 4-10 mm in thickness.
- Lasts from day 6 to 13 (most variable timeline)
Ovulation is the repture of the mature (graafian) follicle and the release of the secondary oocyte into the pelvic cavity, usually occurs on day 14 in a 28 day cycle. During ovulation, the secondary oocyte remains surrounded by its zona pellucid and corona radiata. Increasing levels of estrogen stimulate release of GnRH which stimulates anterior pituitary to release more LH. LH cause rupture of the mature (graafian) follicle and expulsion of a secondary oocyte.
- Events in One Ovary: Afetr ovulation, the mature follicle collapses, and the basement membrane between the granulosa cells and theca interna break down. Once a blood clot forms from minor bleeding of the ruptured follicle, the follicle becomes the corpus hemorrhagicum.Theca interna cells mix with the granulose cells as they become transformed into corpus luteum cell. Stimulated by LH, the corpus luteum secretes progesterone, estrogen, relaxin and inhibin.
- Events in the Uterus: Progesterone and estrogen produced by the corpus luteum growth and coiling of the endometrial glands to 12-18 mm.
The small amount of blood that somitemes leaks into the pelvic cavity from the ruptured follicle can cause pain, known as mittelschmerz, at the time of ovulation.
If the oocyte is not reftilized
If the oocyte is not reftilized, the corpus luteum has a lifespan of only 2 weeks. Then its secretory activity declines and it generates into a corpus albicans. As the levels of progesterone, estrogen and inhibin decrease, release of GnRH, FSH and LH rises. Follicular growth resumes and a new ovarian cycle begin.
If the secondary oocyte is fertilized
If the secondary oocyte is fertilized and begins to divide, the corpus luteum persists past it normal 2-week lifespan. It rescued from degeneration by human chorionic gonadotropin. This hormone is produced by the chorion of the embryo beginning about 8 days after fertilization. Like LH, hCG stimulates the secretory activity of the corpus luteum. The presence of hCG in maternal blood or urine is an indicator of pregnancy.
- Amenorrhea -- absence of menstruation due to hormone imbalance, extreme weight loss or low body fat as with rigorous athletic training
- Dysmenorrhea -- pain associated with menstruation; severe enough to prevent normal functioning. Uterine tumors, ovarian cysts, endometriosis or intrauterine device
- Abnormal uterine bleeding -- excessive amount or duration or intermenstrual. Fibroid tumors or hormonal imbalance
Human Sexual Intercourse
- Excitement phase produced by parasympathetic NS. Engorgement of blood vessels and cardiovascular changes.
- Plateau phase of variable duration.The plateau phase is the period of sexual excitement prior to orgasm sexual flush to face & chest
- orgasm phase (climax). Rhythmical muscular contractions & pleasure. Sympathetic nervous system causes ejaculation
- resolution. Profound relaxation & return to normal. Male refractory period where 2nd ejaculation is impossible
Erectile Dysfunction (Impotence)
Consistent inability of adult male to hold an erection long enough for sexual intercourse. Causes-psychological or emotional factors, physical factors,diabetes mellitus, vascular disturbances, neurological disturbances, testosterone deficiency, drugs (alcohol, nicotine, antidepressants, tranquilizers,etc). Viagra causes vasodilation of penile arteries and brings on an erection.
- Male (vasectomy). Removal of a portion of the vas deferens, incision in posterior scrotal sac.Out patient & local anesthesia. Sperm can no longer reach the exterior. Degenerate and removed by phagocytosis, sexual desire not effected since testosterone levels unchanged
- Female (tubal ligation)-uterine tubes are tied closed and cutsperm can not reach oocyte.
Small object made of plastic, copper or steel left in cavity of uterus. Changes uterine lining so is unfavorable for embryo implantation. Approved for 10 year usage. May cause excessive bleeding or discomfort
- Male & female condoms (vaginal pouch), covers penis or lines vagina.
- Diaphragm/Cervical Cap/Sponge = dome-shaped cap over cervix, prevents entry of sperm into uterus, does not protect against AIDS or STD, may cause recurrent UTIs
Chemical substances in foam, cream, jelly, douche or suppository that kill sperm upon contact
Physiological Methods of Birth Control
- Rhythm method (periodic abstinence). Abstaining from intercourse when secondary oocyte is likely to be possible (3 to 7 days of cycle). 3 days before ovulation, ovulation & 3 days after
- Sympto-thermal method. Observe body for signs of ovulation & abstain form intercourse accordingly. Increased basal body temperature & mucus changes.
- Coitus interruptus. Withdrawal before ejaculation
Abortion refers to the premature expulsion of the products of conception from the uterus, usually before the twentieth week of pregnancy. it may be Spontaneous naturally occurring also called miscarriage. Induced intentionally performed
Types of induced aborption
- One involves mifepristone, called miniprex in the USA and RU 486 in Europe. Mifepristone is an antiprogestin; it blocks the action of progesterone by binding to and blocking progesterone receptors. if the level of progesterone levels falls during pregnancy or if the action of the hormone is blocked, menstruation occurs, and the embryo sloughs off along with the uterine lining.
- Another type of induced abortion is called vacuum aspiration and can be performed up to the sixteenth week of pregnancy. A small, flexible tube attached to a vacuum source is inserted into the uterus through the vagina. The embryo or fetus, placenta, and lining of the uterus are then removed by suction
late stage abortion
A late stage abortion may be employed using surgical method,evacuation (scraping).
Cells of a male embryo have one X chromosome and one Y chromosome. The male pattern of development is initiated by a gene on the Y chromosomes named SRY, which stands for SEX-determining region of the Y chromosomes. When the SRY gene is expressed during development, its protein causes the primitive Sertoli cells to begin to differentiate in the gonadal tissues during the seventh week. The developing Sertoli cells secrete a hormone called Mullerianinhibiting hormone, which cause apoptosis of cells within the paramesonephric ducts. As result, those cells do not contribute any functional structures to the male reproductive system.Stimulated by human chorionic gonadotropin (hCG), primitive Leydig cells in the gonald tissue begin to secrete the androgen testosterone during the 8th week. Testosterone then stimulates development of the mesonephric duct on each side into the epididymis, ductus (vas) deferns, ejaculatory ducts, and seminal vesicle. Testosterone secretion stops at birth when hCG from the placenta stops stimulating leydig cells. If SRY is absent, the gonads develop into ovaries.
Deficiency of 5 Alpha-Reductase
Rare genetic defect producing a deficiency of 5 alpha-reductase. 5 Alpha-Reductaseis an enzyme that converts testosterone into dihydrotestosterone (DHT).
Sexually Transmitted Disease
- Chlamydia -- bacteria; asymptomatic, leads to sterility from scar tissue formation
- Gonorrhea -- bacteria, discharge common, blindness if newborn is infected during delivery
- Syphilis -- bacteria, painless sores (chancre), 2nd stage all organs involved, 3rd stage organ degeneration is apparent (neurosyphilis)
- Genital Herpes -- virus, incurable, painful blisters
- AIDS & hepatitis B --viruses
Growth of endometrial tissue outside of the uterus. Tissue discharged from open-end of uterine tubes during menstruation can cover ovaries, outer surface of uterus, colon, kidneys and bladder. Problem is tissue responds to hormonal changes by proliferating then breaking down & bleeding. Causes pain, scarring & infertility
Most common cause of gynecological deaths excluding breast cancer. Difficult to detect before metastasis. Risk factors- over 50, white, family history, nulliparity, first pregnancy after 30, diet (high fat, low fiber and lack of vitamin A), asbestos & talc. Early symptoms unremarkable -- heartburn, nausea, bloating, loss of appetite, etc
Candida albicans is yeastlike fungus that grows on mucous membranes .Causes vulvovaginal candidiasis or vaginitis, inflammation of the vagina, severe itching and pain, yellow discharge with odor. More likely after antibiotic therapy for some other disease.