Urogenital triangle
It is bounded in front by the
pubic arch & laterally by the
ischial tuberosities .
Superficial fascia
Fatty layer
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 .
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.
Perineal body
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.
Small mass of fibrous tissue which is attached
to the center of the posterior margin of the
urogenital giaphragum. The external anal
Nerve Supply : perineal branch of the pudendal
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 Triangle
It 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 .
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 .
1
2
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 .
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
Sphincter Urethae Muscle : It surrounds the urethra portion of the urethra. Their secretion is as a
in the deep perineal pouch. It arises from the pubic result of erection.
arch on the 2 sides & passes medially to encircle the Deep transverse perineal muscles: They lie
P. to sphincter urethrae. It arises from the
urethra. Its nerve supply is the perineal branch of
pudendal nerve. It is the means by which micturition ischial ramus & passes medially to be
inserted into the perineal body.
can be voluntary stopped.
Dorsal Nerve of Penis: It arises from pudendal N. It Internal Pudendal Artery : It enters the deep
pass forward through deep perineal pouch to skin of perineal pouch & gives rise to the As. Of bulb
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 .