FEMALE REPRODUCTIVE ANATOMY AND REPRODUCTIVE FUNCTION doc

Blood and Lymph Supply The mons is supplied by the external pudendal artery and vein.. Blood Supply The labia majora are supplied by the internal pudendal artery de-rived from the anter

The internal genitalia include the vagina, cervix, uterus,

uter-ine (fallopian) tubes, and ovaries (Figs 2-2 and 2-3) Special

in-struments are required for inspection of the internal genitalia ple specula or other instruments allow direct visualization of thevagina and cervix, but the intraabdominal group can be inspectedonly by invasive methods (laparotomy, laparoscopy, or culdoscopy)

Sim-or by sophisticated imaging techniques (ultrasonography, CT scan,

or magnetic resonance imaging)

EXTERNAL GENITALIA

MONS PUBIS (MONS VENERIS)

The mons veneris, a rounded pad of fatty tissue overlying thesymphysis pubis, develops from the genital tubercle It is not anorgan but a region or a landmark Coarse, dark hair normally ap-pears over the mons early in puberty During reproductive life,the pubic hair is abundant, but after the menopause, it becomessparse The normal female escutcheon is typically a triangle withthe base up, in contrast to the triangle with the base down pat-tern in males

The skin of the mons contains sudoriferous and sebaceousglands The amount of subcutaneous fat is determined by heredity,age, nutritional factors, and possibly, steroid hormone factors

2

FEMALE REPRODUCTIVE

ANATOMY AND REPRODUCTIVE

FUNCTION

FIGURE 2-1. External female genitalia.

Innervation

The sensory nerves of the mons are the ilioinguinal and

gen-itofemoral nerves.

Blood and Lymph Supply

The mons is supplied by the external pudendal artery and vein The

lymphatics merge with those from other parts of the vulva and fromthe lower abdomen The crossed lymphatic circulation of the labiawithin the mons is clinically important because it permits metasta-tic spread of cancer from one side of the vulva to the inguinal glands

of the opposite as well as to the affected side

FIGURE 2-2. Internal female genitalia (superior view).

Clinical Importance

Dermatitis is common in the pubic area, and it is important to

ob-serve closely if infestation with Phthirus pubis (lice, crabs) is

sus-pected Edema can occur secondary to infections, vulvar ties, trauma, or carcinomatous infiltration of the lymphatics Cancerelsewhere in the vulva also can involve the mons

varicosi-LABIA MAJORA

In the adult female, these two raised, rounded, longitudinal folds ofskin are the most prominent features of the external genitalia Theyare homologous to the male scrotum They originate from the gen-ital swellings extending posteriorly and dorsally from the genitaltubercle From the perineal body, they extend anteriorly around the

labia minora to merge with the mons The labia normally are closed

in nulliparous women but later open progressively with succeedingvaginal deliveries and become thin and atrophic with sparse hair inlater life

The skin of the lateral surfaces of the labia majora is thick andoften pigmented It is covered with coarse hair similar to that of themons The skin of the inner labia majora is thin and contains nohairs The labia majora are made up of connective and areolar tis-sue, with many sebaceous glands A thin fascial layer similar to thetunica dartos of the scrotum is present within the labia just belowthe surface The round ligament of the uterus passes through the in-

guinal canal (canal of Nuck) to end in a fibrous insertion in the

an-terior portion of the labia majora

Small and large coiled subcutaneous sweat glands are situatedall over the body except beneath mucocutaneous surfaces, that is,the labia minora or vermilion border of the lips Normally, the fluid

secretion of small coiled (eccrine) sweat glands, which have no lationship to hairs, has no odor Large coiled (apocrine) sweat

re-glands that open into hair follicles are found over the mons, the

labia majora, and the perineum as well as the axilla These glands,which begin to secrete an odorous fluid at puberty, are more activeduring menstruation and pregnancy The sweat glands are controlled

by the sympathetic nervous system

FIGURE 2-3. Internal female genitalia (midsagittal view).

Sebaceous glands are associated with and open into hair cles On the labia minora, where hairs are absent, however, seba-ceous glands open on the surface At puberty, an oily secretion with

folli-a slight odor is produced The fluid lubricfolli-ates folli-and protects the skinfrom irritation by vaginal discharge Gland secretion is mediated byhormonal and psychic stimuli The activity of the sebaceous glandsdiminishes in older women

Innervation

Anteriorly, the labia majora are supplied by the ilioinguinal and

pu-dendal nerves Laterally and posteriorly, they are innervated by the posterior femoral cutaneous nerve.

Blood Supply

The labia majora are supplied by the internal pudendal artery

(de-rived from the anterior parietal division of the internal iliac or

hy-pogastric artery) and by the external pudendal artery (from the femoral artery) Drainage is via the internal and external pudendal

veins.

Clinical Importance

The labia majora serve no special function A cyst of the canal

of Nuck often is mistaken for an indirect inguinal hernia

Adher-ence of the labia in infants may indicate vulvitis External force

or the complications of labor can cause vulvar hematoma

Hidrade-nomas are tumors that originate in aprocrine sweat glands, but

they become malignant only rarely Sebaceous cysts, almost

invariably benign but often infected, develop from sebaceousglands

or introitus Anteriorly, each labium merges into a median ridge that

fuses with its mate to form the clitoral frenulum, an anterior fold that becomes the prepuce of the clitoris.

The lateral and anterior surfaces of the labia minora usually arepigmented Their inner aspect is pink and moist, resembling thevaginal mucosa

The labia minora have neither hair follicles nor sweat glandsbut are rich in sebaceous glands

Innervation and Blood Supply

The innervation of the labia minora is via the ilioinguinal,

puden-dal, and hemorrhoidal nerves The labia minora are not truly

erec-tile, but a generous vasculature permits marked turgescence with

emotional or physical stimulation They are supplied by the nal and internal pudendal arteries and veins.

exter-Clinical Importance

The labia minora tend to close the introitus They increase in size

in response to ovarian hormonal stimulation Indeed, without

es-trogen stimulation, they all but disappear Squamous cell carcinoma

of the vulva often originates in the labia, as do sebaceous cysts The

presence of adherent labia minora in the infant is usually due to inflammation Fusion, however, may indicate sexual maldifferenti-

ation

CLITORIS

This 2–3 cm long homolog of the penis is found in the midlineslightly anterior to the urethral meatus It is composed of two small,erectile corpora, each attached to the periosteum of the symphysis

pubis, and a diminutive structure (glans clitoridis) that is

gener-ously supplied with sensory nerve endings The glans is partiallyhooded by the labia minora

Innervation and Blood Supply

The clitoris is supplied by the hypogastric and pudendal nerves,

pelvic sympathetics, and by the internal pudendal artery and vein.

Clinical Importance

Cancer of the clitoris is rare, but it is extremely serious because of

problems of wide extension and early metastases The inguinal andfemoral nodes usually are involved first

VESTIBULE AND

URETHRAL MEATUS

The triangular area between the labia minora anteriorly onto whichthe urethra opens, bounded posteriorly by the vaginal orifice, is the

vaginal vestibule It is derived from the urogenital sinus and is

cov-ered by delicate stratified squamous epithelium

The urinary meatus is visible as an anteroposterior slit or an inverted V Like the urethra, it is lined by transitional epithelium.

The vascular mucosa of the meatus often pouts or everts Thismakes it appear more red than the neighboring squamous vaginalmucosa

Innervation and Blood Supply

The vestibule and terminal urethra are supplied by the pudendal

nerve and by the internal pudendal artery and vein.

Clinical Importance

Urethral caruncles, as well as squamous cell or transitional cell

car-cinoma, can develop in the urethrovestibular area.

PARAURETHRAL GLANDS

(SKENE’S GLANDS)

Immediately within the urethra, on its posterolateral aspect, are two small orifices leading to the shallow tubular ducts or glands of

Skene, which are wolffian duct remnants The ducts are lined by

transitional cells and are the sparse equivalent of the numerous maleprostate glands

Innervation and Blood Supply

Like the vestibule and urethral meatus, Skene’s glands are supplied

by the pudendal nerve and by the internal pudendal artery and vein.

Clinical Importance

Skene’s glands, which supply minor amounts of mucus, are

espe-cially susceptible to gonococcal infection, which may be first

evi-dent here After successful antigonorrheal therapy, nonspecific fection with other purulent organisms is common and results in

in-recurrent skenitis Destruction of the duct using electrocautery or

laser may be necessary

PARAVAGINAL OR VULVOVAGINAL

GLANDS AND DUCTS

(BARTHOLIN’S GLANDS

AND DUCTS) AND HYMEN

Just external to the hymen are paravaginal, vulvovaginal glands, orBartholin’s glands, the counterpart of Cowper’s glands in the male

On either side are two tiny apertures A narrow duct, 1–2 cm long,connects each of these apertures with a small, flattened, mucus-producing gland that lies between the labia minora and vaginal wall

The hymen is a thin, moderately elastic barrier that usually partially

but rarely completely occludes the vaginal canal It is an incompletedouble-faced epithelial plate covering a matrix of fibrovascular tissue.Innervation and Blood Supply

The hymen and area of the Bartholin’s glands are supplied by the

pudendal and inferior hemorrhoidal nerves, arteries, and veins.

Clinical Importance

Bartholinitis can occur with sexually transmitted diseases, cially gonorrhea, and an abscess of Bartholin’s duct can require mar-supialization

espe-A tight hymen can result in painful intercourse (dyspareunia),

in which case, hymenotomy or dilatation will be required The nants of the lacerated hymen following intercourse or delivery are

rem-called carunculae hymenales (myrtiformes) Hymenal or perineal

scars also can cause dyspareunia

PERINEAL BODY, FOURCHETTE,

AND FOSSA NAVICULARIS

The perineal body includes the skin and underlying tissues betweenthe anal orifice and the vaginal entrance The perineal body is sup-

ported by the transverse perineal muscle and the lower portions of the bulbocavernosus muscle.

The labia minora and majora converge posteriorly to form a

low ridge called the fourchette Between this fold and posterior

to the hymen is a shallow depression termed the fossa

navicu-laris.

Innervation and Blood Supply

These structures are supplied by the pudendal and inferior

hemor-rhoidal nerves, arteries, and veins.

Clinical Importance

The perineal body or fourchette often is lacerated during childbirth

and can require repair Because of vascularity, an early or deep siotomy can result in the loss of several hundred milliliters of blood

epi-Faulty repair can be followed by dyspareunia or by reduced sexual

timeters into the upper vagina to form recesses called the fornices.

The posterior fornix is usually deeper than the anterior fornix Thelateral fornices are similar in size The vaginal dimensions are reduced

during the climacteric, and all fornices, especially the lateral ones,become more shallow.

The vagina lies between the urinary bladder and the rectum and

is supported principally by the transverse cervical ligaments

(car-dinal ligaments) and the levator ani muscles.

The peritoneum of the posterior cul-de-sac (pouch of Douglas)

is closely approximated to the posterior vaginal fornix, a detail of

surgical importance

The vagina is lined by stratified squamous epithelium, which isthick and folded transversely in nulliparas Many of these rugae arelost with repeated vaginal delivery and after the menopause Nor-mally, no glands are present in the vagina

Innervation and Blood Supply

The nerve supply to the vagina is via the pudendal and

hemor-rhoidal nerves and the pelvic sympathetic system (Fig 2-4) The

blood supply is from the vaginal artery (a descending branch of the uterine artery) and from the middle hemorrhoidal and internal pu-

dendal arteries It is drained by the pudendal, external rhoidal, and uterine veins.

hemor-The lymphatic drainage of the lower vagina is via the

superfi-cial inguinal nodes; that of the upper vagina is to the presacral, ternal iliac, and hypogastric nodes This is important in vulvo-

ex-vaginal infections and cancer spread

Clinical Importance

Vaginal discharge is common and can be due to local or systemic

disorders Infections of the lower reproductive tract are the mostcommon cause of leukorrhea Estrogen depletion (senile or atrophicvaginitis) and estrogen or psychic stimulation are other causes.Primary cancer of the vagina is very rare, but secondary spread fromcervical cancer is not uncommon

CERVIX

The cervix of the nonpregnant uterus (Fig 2-3) is a conical, erately firm organ about 2–4 cm long and some 2.5 cm in outsidediameter, with a central, spindle-shaped canal About half the length

mod-of the cervix is supravaginal and close to the bladder anteriorly

Childbirth lacerations account for most cervical distortions The

external os, which is initially round and only a fraction of a timeter in diameter, may gape and be much longer as a result ofthese tears Even in the absence of distortions, however, it is cus-tomary to refer to the cervix as having anterior and posterior lips

cen-The cervix is supported by the uterosacral ligaments and

trans-verse cervical ligaments (cardinal ligaments).

The intravaginal portion of the cervix is covered by stratifiedsquamous cells, which usually extend to approximately the exter-nal os The cervical canal is lined by secretory columnar epithe-lium The juncture of these two epithelia is variable and is subject

to continual revision under the influence of infections, hormones,and trauma The countless crevices that give the cervical canal ahoneycombed appearance on transverse section are infoldings ofthe mucus-secreting membrane

Excluding the epithelial covering and the cervical canal, the

cervix is composed of approximately 85% connective tissue and

15% smooth muscle fibers that join the uterine myometrium above.

The anatomic structure of the cervix undergoes marked alterationduring pregnancy, labor, and delivery

Innervation and Blood Supply

Innervation of the cervix is via the second, third, and fourth sacral

nerves and the pelvic sympathetic plexus (Fig 2-4) The right and

left cervical artery and vein, major branches of the uterine

circula-tion, carry most of the blood to and from the cervix

Clinical Importance

The red appearing, more friable columnar epithelium over the

endo-cervix is responsible for ectropion and may contribute to postcoital

bleeding and infection Additionally, the squamocolumnar junction is

the site of
90% of squamous cell carcinomas of the cervix

Cervi-cal cancer is the second most common female genital malignant plastic disease (Endometrial cancer is the most common.) Cervical infection may be a contributor to infertility Leukorrhea often is due

neo-to inflammation of the mucus-secreting membrane.

UTERUS

The uterus (Figs 2-2 and 2-3) is an inverted, pear-shaped lar organ with a narrow central cavity situated deep in the true pelvis

muscu-between bladder and rectum The central cavity, which is lined by

endometrium, is roughly triangular with the base up and is markedlycompressed in the anterior-posterior Each of the upper apices is

connected to an oviduct, and the lower apex merges with the

in-the supravaginal segment of in-the cervix In contrast to in-the cervix,

the uterine substance (myometrium) is 85% smooth muscle and only

15% connective tissue Except for the anteroinferior portion of the

corpus, which is invested by the bladder, the uterus is covered by

peritoneum.

The adult nonpregnant uterus weighs about 90 g and is about7–8 cm long and about 4 cm in its widest diameter However, con-siderably larger sizes and increased weight occur with hormonalstimulation and after childbirth During pregnancy, the uterus, whichincreases to weigh about 1000 g, literally balloons to accommodatethe gestation

The uterus is supported by three paired ligaments Uppermost are the round ligaments, which pass from the uterine fundus ante-

rior to the uterine tube to the internal inguinal canal Laterally oneach side from inferior to the uterine tube extending to the cervix

and attached to the pelvic side wall are the cardinal ligaments The

uterosacral ligaments extend from each sacral attachment to the

posterior uterocervical juncture

In the nulliparous woman, the uterus and cervix usually are rected forward at almost a right angle with the long axis of the

di-vagina However, 25%–35% of women normally have retroverted

or retroflexed uteri.

Innervation and Blood Supply

The nerves to the uterus include the superior hypogastric plexus, the inferior hypogastric plexus, the nervi erigentes, the common il-

iac nerves, and the hypogastric ganglion (Fig 2-5).

The uterine artery (a terminal branch of the hypogastric) is the primary souce of blood to the uterus, and the ovarian artery is a contributor The uterine artery passes anterior to the ureter lateral

to, but near, the uterocervical junction This is a very important

anatomical land mark! The veins draining the uterus are primarily

the uterine veins and secondarily the ovarian veins.

Lymphatic drainage may be through the cervix to the external

iliac chain or via the isthmus to the lateral sacral nodes Lymph

drainage within the round ligaments may extend to the superifical

inguinal nodes, then to the femoral, and finally, to the external iac chain Drainage through the suspensory ligament of the ovary

il-proceeds to the lumbar nodes along the aorta, above or below the

(From J.J Bonica, The nature of pain of parturition Clin Obstet Gynecol 1975;2:511.)

usually of uterine origin Occasionally, congenital (e.g., tate uterus, uterus unicollis) or acquired defects (e.g., Asherman’s syndrome) make pregnancy difficult With the exception of child-

subsep-birth, the uterus is infrequently subject to infection The

my-ometrium is rarely the site of malignancy Endometrial cancer, however, is the most common female genital cancer The my-

ometrium is very commonly the site of benign uterine leiomyomas and, less frequently, is locally honeycombed by endometrium, re-

sulting in adenomyosis.

UTERINE TUBES

(FALLOPIAN TUBES)

Both uterine tubes function to convey the ova to the uterus from the

ovary Bilaterally, these tubes lie in the peritonealized superior

border of the broad ligament termed the mesosalpinx Each tube is

7–14 cm in length and generally is horizontal near the uterus Onreaching the lower ovarian pole, it courses around the ovary to ter-minate by contact with the ovarian medial posterior surface

Each tube is divided into the isthmus, ampulla, and

infundibu-lum The most medial segment is the isthmus It is narrow in

di-ameter, ending its uterine intramural course with an ostium of

⬃1 mm More distal to the isthmus is the ampulla, which is moretortuous and wider The ampulla terminates distally in the funnel-shaped infundibulum, which has as its most distal margin a series

of fingerlike diverging processes, the fimbriae The funnel-shaped

mouth of the infundibulum, excluding the widely reaching fimbriae,

is about 3 mm in diameter and opens into the peritoneal cavity The

infundibulum is loosely supported by the infundibulopelvic

liga-ment (suspensory ligaliga-ment of the ovary).

The tubal wall consists of serous (peritoneal), subserous or ventitial (vascular and fibrous), muscular, and mucous components

ad-The muscular layer is composed of outer longitudinal and inner

cir-cular smooth muscle layers The mucosa is a ciliated columnar cretory epithelium arranged in longitudinal folds that become morecomplex in the ampullae Its ciliary motion is directed toward theuterus

se-Innervation and Blood Supply

The oviductal nervous supply is from the pelvic and ovarian

parasympathetic and sympathetic plexuses The tubal blood supply

is from the tubal branch of the uterine artery and from the ovarian

branch of the uterine artery The venous drainage is through the

tubal veins accompanying the arteries The lymphatic drainage comes retroperitoneal to the lumbar aortic nodes

be-Clinical Importance

Tubal pregnancy and either intraluminal (usually gonococcal or

chlamydial) or peritubal (often streptococcal) infections are the most

common clinical concerns relative to the uterine tubes Tubal tortion from peritubal scarring by endometriosis or infection, as well

dis-as intraluminal problems, can predispose to infertility Tubal

can-cer is very uncommon but serious.

OVARIES

The ovaries are a pair of slightly flattened, ovoid organs that pear mottled pearly white with many surface irregularities They lie

ap-below the pelvic brim and are supported by the ovarian ligaments

(which extend from the uterus to the medial ovarian pole) and the

infundibulopelvic ligaments The ovaries rest in a fossa on the pelvic

sidewall lined by peritoneum They are bounded above by the

ex-ternal iliac vessels, below by the obturator nerve and vessels, teriorly by the ureter and uterine artery and vein, and anteriorly by the pelvic attachment of the broad ligament The uterine tubes are

pos-draped over the medial surface of the ovaries

The ovaries weigh 4–8 g each and are usually 2.55 1.53  0.71.5 cm They are covered by a cuboidal or low colum-

nar epithelium and are divided into a medulla (consisting of

nu-merous blood vessels, lymphatics, nerves, connective tissue, and

smooth muscle) and a cortex (consisting of fine areolar stroma, many blood vessels, and scattered epithelial cells arranged in fol-

licles).

The graafian follicles contain the oocytes, which with

matura-tion (i.e., selecmatura-tion for ovulamatura-tion) enlarge sufficiently to protrudevisibly from the ovarian surface When fully mature, the ovum is

released and the follicle is transformed into a corpus luteum This,

in turn, is replaced by scar tissue (termed corpus albicans).

Innervation and Blood Supply

The ovarian nerve supply is from the lumbosacral sympathetic chain and passes to the ovary along the ovarian artery The ovarian ar-

tery (usually a branch of the abdominal aorta, although the left not infrequently arises from the left renal artery) is the primary blood

supply to the ovary However, blood is also supplied from the

anas-tomosing ovarian branch of the uterine artery The veins follow the arteries to form the pampiniform plexus within the mesovarium The

right ovarian vein empties into the vena cava, whereas the left ian vein usually enters the left renal vein The lymphatics drain retroperitoneally to the aortic lumbar nodes.

ovar-Clinical Importance

The principal functions of the ovaries include hormone productionand the development of ova for the achievement of pregnancy These

functions can be interrupted by many factors The ovaries are a

fre-quent site of benign and malignant ovarian tumors Torsion can

oc-cur, leading to vascular insufficiency and necrosis Ovarian

infec-tions also occur, usually in premenopausal women.

THE PELVIC FLOORThe pelvic floor (Figs 2-6 and 2-7) consists of muscles, ligaments,and fascia arranged in such a manner as to support the pelvic vis-cera; provide sphincterlike action for the urethra, vagina, and rec-tum; and permit the passage of a term infant It is composed of the

upper and lower pelvic diaphragms and the vesicovaginal and tovaginal septa, which connect the two diaphragms, the perineal body, and the coccyx Other structures contributing to the integrity

rec-FIGURE 2-6. Fascial planes of the pelvis

of the pelvic floor include the transverse cervical (cardinal or

Mackerrodt’s) ligaments and the gluteus maximus muscles.

The upper pelvic diaphragm is a musculofascial structure made

up of endopelvic fascia, the uterosacral ligaments, and the levator

ani muscles (including the pubococcygeus portion) The lower culofascial pelvic diaphragm includes the urogenital diaphragm and

mus-the sphincter muscles at mus-the vulvar outlet (ischiocavernosus,

bul-bocavernosus, and transverse perineal muscles).

All parts of the upper and lower musculofascial diaphragms

an-chor into the perineal body directly or indirectly, like spokes into

FIGURE 2-7. Pelvic musculature (inferior view).

the hub of a wheel or shroud lines into the ring of a parachute Forreciprocal support, the layers of the pelvic diaphragms are inter-woven and superimposed They are not fixed but move upon oneanother This makes it possible for the birth canal to dilate duringpassage of the fetus and to close postpartum

The pelvic floor is perforated centrally by three tubular

struc-tures: urethra, vagina, and rectum Each traverses the pelvic floor

at a different angle, which enhances the sphincterlike action of thepelvic muscles

The different tissues of the musculofascial diaphragm play an

important role in providing both support and resilience The

con-nective tissue provides support but no recoil, the fascia gives

strength but no elasticity, the elastic tissue has resilience but little strength, and the voluntary and smooth muscles provide stretch and

recoil but with limited tolerances

Weakness or relaxation of the pelvic floor can be due to a

neu-ropathy or an injury during childbirth, or it can be of congenital or involutional origin.

THE BONY PELVIS

The bony pelvis is composed of four bones, the sacrum and coccyx

(posterior) and the two innominate bones laterally and anteriorly.

The spinal column articulates (through an arthrodial joint) with the sacrum at L5 Bilaterally, the innominate bones rest on the femurs,

articulating by enarthroses (Figs 2-8, 2-9, 2-10, and 2-11) Within

the pelvis itself are two types of joints, a synchondrosis uniting the two pubic bones and diarthroses between the sacrum and ilium and between the sacrum and coccyx The innominate bones have three major sections: ilium, ischium, and pubis.

The ilium is composed of the upper part (ala or wing) and a lower part (body) that forms the upper part of the acetabulum, unit- ing with the ischium and pubis Medially, the ala of the ilium pre- sents a smooth concave area that anteriorly is the iliac fossa and pos- teriorly is the iliac tuberosity (superior) and the sacral articulation

(inferior) The superior border of the ilium (crest) is bounded by the

anterior and posterior superior iliac spines and serves to attach the

following muscles: external oblique, internal oblique, transversus (anterior two thirds), latissimus dorsi, quadratus lumborum (poste- rior), sacrospinalis, tensor fascia latae, and sartorius muscles The lateral surface of the ilium provides attachments for the gluteal mus-

cles The posterior border of the iliac is marked by the posterior

por-tion of the greater sciatic notch Blood supply to the ilium is from the iliolumbar, deep circumflex iliac, obturator, and gluteal arteries.