Urogenital triangle

It is bounded in front by the pubic arch & laterally by the

ischial tuberosities.

Superficial fascia

1 -The fatty layer is continuous with the fat of the ischiorectal fossa & the upper part of the thigh. It is replaced by the dartos muscle in

the scrotum .

2 -The membranous layer is attached posteriorly to the posterior border of the urogenital diaphragm & laterally to the margin of the pubic arch & anteriorly it is continuous with the membranous layer of the of the anterior abdominal wall . This fascia is continued over the penis or clitoris as a tubular sheath . In the scrotum or labia

majora it forms a distinct layer.

Superficial fascia of the thigh

The fatty layer of the fascia extends into the thigh & continues down over the lower limb without iterruption.

The membranous layer extends into the thigh & becomes attached to the deep fascia after about a fingerbreadth ( 8 cm ) below

the inguinal ligament.

Fatty layer

Superficial Perineal Pouch

It is bounded below by the membranous layer of the superficial fascia & above by the urogenital diaphragm.

It is closed behind by the fusion of its upper & lower walls .

Laterally , it is closed by the attached membranous layer with the urogenital diaphragm to the

margins of the pubic arch. Anteriorly, It communicates with the space lying between the superficial fascia & the muscles of

the anterior abdominal wall.

Superficial Perineal Pouch In Male

It contains structures forming the root of the penis,with the muscles that cover them .

1-The bulbospongiosus Ms.,are situated one on each side of the midline & cover the bulb of the penis & the posterior portion of the corpus

spongiosum .

2 -Ischiocavernosus Ms., they cover the crus penis on each side .

Superficial Transverse Perineal Ms.,Each muscle arises from the ischial tuberosity & inserted into the perineal body. The function of them is to fix

the perineal body in the center of the perineum .

Nerve Supply : perineal branch of the pudendal N .

Perineal body Small mass of fibrous tissue which is attached to the center of the posterior margin of the urogenital giaphragum. The external anal

sphincter and 1 ( o ) & 3 ( In) are attached to it.

Penis It has a fixed root & a body . Its root is made up of 3 masses of erectile tissue called bulb of penis and R.& L. crura of penis. The bulb is attached to the undersurface of the urogenital diaphragm and is continued forward into the body to form Corpus Spogiosum ( spongy urethra is present within them ). Each crus is attached to side of pubic arch and

lie side by side in the dorsal part of the body of penis, forming the corpora cavernosa .

Body Of Penis :It is made up of 2 dorsally placed corpora cavernosa, which communicate with each other . & a single corpus spongiosum applied to ventral surface. The 3 are erectile tissue. The corpus spongiosum expands to form the glans penis. On the tip of the glans penis is the external urethral meatus. Arteries from internal pudendal & veins into internal pudental. The corpora cavernosa by the deep arteries of the penis& the corpus spongiosum by the artery of the bulb & dorsal artery of the penis. Nerve supply: pudental N. & pelvic plexuses. Lymph Drainage: The skin into medial

group of superficial inguinal nodes. The deep structures into internal iliac nodes .

Superficial Perineal Pouch In Female

It contains the root of the clitoris & muscles that cover them .

1 -Bulbospongiosus muscles : they surround the orifice of the vagina & cover the vestibular bulbs. Their fibers extend forward to gain attachment to the corpora

cavernosa of the clitoris . 2 -The ischiocavernosus muscles :

They cover the crus of the clitoris Superficial T. perineal muscles : like male.

Nerve supply : The perineal branch of the pudendal nerve .

Perineal Body : Is larger than male . It is a wedge- shaped mass of fibrous tissue situated between the lower end of the vagina & anal canal . It supports the posterior wall

of the vagina .

Female Urogenital TriangleIt contains the external genitalia and orifice of the urethra & vagina Clitoris : It corresponds to penis. Is situated at the apex of the vestibule anteriorly. Root of clitoris is made of 3 erectile masses , the bulb of the vestibule & R. and L. crura . The bulb is divided into 2 halves The crura become the corpora cavernosa anteriorly. Body of clitoris :It consists of the 2 corpora cavernosa. The corpus spongiosum is present by a small amount of erectile tissue leading from the vestibular bulbs to the glans. Glans of the clitoris It is a small mass of erectile tissue that caps the body . The glans is partly

hidden by prepuce .Blood supply, Lymph drainage , Nerve supply are similar to those of

the male penis.

Vulva ( Female external genitalia ) 3-Labia minora : their posterior ends are united to form the fourchette . Anteriorly, they enclose the clitoris , forming prepuse & posterior frenulum. 4-Vestibule : is a triangular area bounded laterally by the labia minora Anterior by the clitoris .Posterior by fourchette. 5- Vaginal Orifice : it is protected by hymen. 6Orifices of the ducts of the greater vestibular glands are found in the groove between the hymen & the posterior part of the labium minus. Blood supply : external & internal pudendal arteries . Nerve supply : Anterior parts are supplied by ilioinguinal & genital branch of genitofemoral . The posterior parts are supplied by branches of the perineal nerves & posterior cutaneous nerves of the thigh . Lymph drainage : into medial group of

superficial inguinal nodes.

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2

Urogenital Diaphragm

It is a triangular musculofascial diaphragm. It fills the gap of the pubic arch .It is formed by the sphincter urethrae & the deep transverse perineal ms.These muscles are enclosed between a superior & inferior layers of fascia of this diaphragm. The inferior fascia is called perineal membrane. The closed space that is between the 2 layers of the fascia is known as the deep perineal pouch

Anteriorly , the 2 layers of fascia fuse , leaving a small gap beneath the symphysis pubis . They form the anterior transverse perineal ligament.

Posteriorly , the 2 layers of fascia fuse with each other & with the membranous layer of

the superficial fascia & the perineal body.

Deep perineal pouch in Male

It contains the membranous part of the urethra; sphincter urethra; bulbourethral glands; the deep transverse perineal muscles; the internal pudendal vessels & their branches and the dorsal nerves of the

penis .

Membranous part of the urethra: It is about 1.3 cm long & lies within the urogenital diaphragm & is surrounded by the sphincter urethra muscle. It continuous above with the prostatic urethra & below with the penile urethra . It is the shortest & least dilatable part of the urethra.

Bulbourethral Glands: they lie beneath the sphincter urethrae muscle. Their ducts pierce the perineal membrane & enter the penile portion of the urethra. Their secretion is as a result of erection. Deep transverse perineal muscles: They lie P. to sphincter urethrae. It arises from the ischial ramus & passes medially to be inserted into

the perineal body .

Internal Pudendal Artery : It enters the deep perineal pouch & gives rise to the As. Of bulb ; crura and dorsal a. of penis to skin& fascia.

Sphincter Urethae Muscle : It surrounds the urethra in the deep perineal pouch. It arises from the pubic arch on the 2 sides & passes medially to encircle the urethra. Its nerve supply is the perineal branch of pudendal nerve. It is the means by which micturition can be voluntary stopped. Dorsal Nerve of Penis: It arises from pudendal N. It pass forward through deep perineal pouch to skin of

penis .

Deep Perineal Pouch in Female

It contains part of the urethra & part of vagina.

The sphincter urethrae, which is pierced by the urethra & vagina. ( like male ) .

The deep transverse perineal muscles(like male ) .

Internal pudendal vessesls & their branches and the dorsal nerves of the clitoris ( their arrangement similar to male)

Urethra : it opens into the vestibule about 2.5 cm below the clitoris. It traverses the sphincter urethrae & lies immediately infront of the vagina. At the sides of the external urethral meatus are small openings of the ducts of the paraurethral

glands .

Some of differences between the male & female pelvis

The cause of pelvic deformities may be due to:

1 -congenital 2- required due to

a. disease

b. poor posture

c. fractures

d. rickets

Deformities of the pelvis may be responsible for

dystocia ( difficult labor )

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2

3

4

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Female pelves are classified into 4 groups

1 -Normal

2 -The inlet is ovale , long; narrow.

3 -Contracted outlet.

4-Promontary is pushed forward & the inlet is flattened.

Estimation of the transverse diamerter ( width ) of the pelvic outlet by means of

a closed fist

Injury to the pelvic floor

It results in the loss of support for the pelvis viscera leading to

1 -Utrine & Vaginal prolapse.

2 -Herniation of the bladder ( cystocele )

3 -Alteration in the position of the bladder neck & urethra ( the normal angle between the urethra & the posterior wall of the bladder is lost ) leading to stress incontinence ( the

patient dribbles urine as in coughing ) .

4 -Prolapse of the rectum.

Fascial ligaments of the uterine cervix

They assist to prevent uterine prolapse .

The visceral pelvic fascia around the uterine cervix & vagina is referred as the

parametrium.

Primary Megacolon

It is more common in male than in female .The child fails to pass meconium; the abdomen becomes distended due to distention of the sigmoid colon which is hyper trophied while the rectum & anal canal are constricted the cause is due to complete failure of development of the parasympathetic ganglion cells in this region . Excision of

the aganglionic segment of the bowel .

Tubal Ligation

It is used to obtain permanent birth control . If the ova is discharged from the ovarian follicles it will degenerate in the tube proximal to the obstruction. Fertilization can occur again in

about 20 % of women.

Pelvic Inflammatory Disease

Ascending infection from the cervix can occur & is followed by infection of the tubes ( Salpingitis) Leakage of pus into the peritoneal cavity causes pelvic peritonitis & pelvic abscess or general

peritonitis.

Cysts of the Ovary

Follicular cysts : are common & originate in unrupture graafian follicles.It does not exceed to 1.5 cm. Luteal cysts : Fluid is retained in the corpus luteum which cannot become fibrosed. It does

not exceed to 3 cm.

The Rectouterine Pouch & Disease

The pouch lies directly behind the posterior fornix of the vagina. It becomes the site for the accumulation of blood ( from a ruptured ectopic pregnancy ). Or pus from a ruptured pelvic appendicitis or in gonococcal peritonitis . Culdocentesis is a passage of a needle into the pouch through the posterior fornix . The interior of the female pelvic peritoneal cavity can be viewed by using an

endoscope through a small colpotomy incision .

Internal Hemorrhoids ( piles ) They are varicosities of the tributaries of the superior rectal vein and are covered by mucous

membrane & the submucosa . These tributaries lie in the anal canal columns at the 3, 7, and 11 o’clock positions when the patient is viewed in the lithotomy position. Also, it may contain a terminal branch of the superior rectal

artery .The first degree is within the anal canal

If they extrude from the anal canal on defecation then return at the end of the act ( 2nd degree).

If they elongate & prolapse on defecation and remain outside the anus ( 3rd degree).

They occur in the upper half of the anal canal which is innervated by autonomic afferent nerves, so they are painless but may give rise to an aching sensation. They are sensitive to stretch.

The causes are : 1- The vein is valveless 2- A congenital weakness of the vein wall 3- Chronic constipation 4- Pregnancy due to pressure on the vein. 5-Portal hypertension . N.B. The possibility that cancer of rectum is

blocking the vein must never be overlooked .

External Hemorrhoids

They are varicosities of the tributaries of the inferior rectal vein.

They are covered by mucous membrane or skin .

They are sensitive to pain ,temperature, touch and pessure & are innervated by the inferior rectal

nerves. So , they are painful.

Thrombosis of an external hemorrhoid is common.

Anal Fissure

The anal columns are connected by anal valves ( folds). In chronic constipation , these valves can torn down to the anus ( as a result of catching on the fold of the mucous membrane by the edges of the

fecal mass .

The elongated ulcer known as an anal fissure . It occurs mostly in the midline

posteriorly or ,less anteriorly. The cause is due to sweep of the superficial part of the external sphincter in the lateral sides of the anal canal and not encircle it . This means that there is lack in the support

The site of the anal fissure in the sensitive lower half of the anal canal , which is innervated by the inferior rectal nerve, results in reflex spasm of the external anal

sphincter . For this pain the fissure must examine

under local anethesia.

The Ischiorectal Fossae & Infection

They are filled with fat that is poorly vascularized .

1-Infection commonly tracks laterally from the anal mucosa through the external anal sphincter .

2-Infection of the perianal hair follicles or sweat glands can cause infection in the fossae .

Rarely, a perirectal abscess bursts downward through the levator ani muscle .

An ischiorectal abscess may involve the opposite fossa by spread of infection across the midline

behind the anal canal.

Rectal examination

The following structures can be palpated by the gloved index finger inserted into the

anal canal & rectum. Anteriorly : In the female In the male

Opposite Rectouterine RectovesicalTerminal vagina vas deferencePhalanx cervix P. surface of bl

seminal vesicle

Opposite urogenital RectoprostaticMiddle diaphragm fasciaPhalanx vagina prostate

Opposite perineal perineal bodyProximal body urogenital diaphPhalanx lower part bulb of penis

of vagina

Posteriorly: the sacrum, coccyx and anococcygeal body

Laterally : ischiorectal fossa & ischial spines.

Injury To Perineum During Childbirth

During childbirth, the perineal body can be damaged by laceration causing

permanent weakness of the pelvic floor . Also, tear of the lower third of the posterior wall of the vagina and the

overlying perineal skin. In sever tears the lacerations may extend backward into the anal canal & damage the external sphincter. In this case an accurate repair of the walls of the anal canal, vagina and perineal body must

done .

During second stage of labor , when the baby’s head is presenting at the vaginal orifice episiotomy is done.

Episiotomy may be median or mediolateral which is performed usually . The incision is made through the perineal skin. It is a median incision that turns

laterally as it proceeds posteriorly .Episiotomy is used in breech & forceps

deliveries .

Vaginal examination

This examination is used to know the health of the vaginal walls , the uterus, and thesurroundin g structures

The upper half of the vagina lies above pelvic floor between the bladder anteriorly & the rectum posteriorly.

The lower half lie within the perineum between the urethra anteriorly & the anal canal posteriorly.

Pudental Nerve Block

Area of Anesthesia: Is the skin of perineum.It abolish sensation from the posterior part of perineum that is because the anterior part is innervated by the ilioinguinal & genitofemoral nerves. So, it does not abolish pain from uterine contractions that ascend to spinal cord via the sympathetic afferent nerves Indications : Forceps delivery & episiotomy.