2. PERINEUM
• It is a diamond shaped space at the
lower end of trunk and lies between
the thighs.
• Pelvic outlet
• It lies below the pelvic diaphragm.
12/29/18 2
4. An imaginary transverse line joining the anterior
ends of the ischial tuberosities divides the
perineum into two triangles -
12/29/18 4
5. DIVISIONS OF PERINIUM :
• BOUNDERIES OF UGT
• In front
• Pubis symphsis and arcuate pubic
ligament.
• Behind
• Imaginary horizontal line.
• Each side
• Ischio-pubic ramus.
12/29/18 5
6. DIVISIONS OF PERINIUM :
• BOUNDERIES OF Anal
Triangle
• Behind
• Coccyx
• In Front
• Imaginary horizontal line.
• Each side
• Sacrotuberous Ligament.
12/29/18 6
7. UROGENITAL REGION
• INTRODUCTION
• LAYERS
• SUPERFICIAL AND DEEP PERINEAL POUCHES
• UROGENITAL DIAPHRAGM
• PERINEAL BODY
• APPLIED
12/29/18 7
8. Urogenital Triangle
• Transversely across the rami, three
membranes
• From above downwards
• Superior fascia of urogenital diaphragm
• Perineal membrane / Inferior fascia of
urogenital diaphragm
• Membranous layer of superificial fascia
12/29/18 8
9. Urogenital Triangle
• Two spaces
• Deep Perineal Pouch- between
Superior fascia of urogenital diaphragm
and Perineal fascia / Inferior fascia of
urogenital diaphragm
• Superificial Perineal Pouch- between
Perineal fascia / Inferior fascia of
urogenital diaphragm and Membranous
layer of superificial fascia
12/29/18 9
10. Superior fascia of urogenital diaphragm
Inferior fascia of urogenital diaphragm
(Perineal Membrane)
Superficial fascia of perineum
(colles’ fascia)
Deep perineal space
Superficial perineal space
12/29/18 10
11. Urogenital Triangle
• Posteriorly, all three membranes are
attached to the perineal body.
• Anteriorly, Superior and Inferior fascia of
urogenital diaphragm fuse a little behind
pubic symphysis -transverse ligament of
pubis
• Dorsal vein of penis
• Anteriorly, Membranous layer continues
with anterior abdominal wall
12/29/18 11
12. SUPERFICIAL PERINEAL
POUCH
• Boundaries :
• Above – Perineal membrane
• Below – Colle’s fascia
• On each side – Inner surface of
Ischiopubic rami
• Behind – Closed by the union of
perineal membrane with Colle’s
fascia.
• In front – Open and continuous
with the spaces of scrotum, penis
and anterior abdominal wall.
Definition :
• It is the interfacial space of Urogenital region below the perineal
membrane.
12/29/18 12
13. SUPERFICIAL PERINEAL
POUCH• Contents
• Muscles － superficial transverse perineal muscle, bulbospongiosus, crus
penis (male), crus of clitoris (female) and ischiocavernousus
• Central part － bulb of penis (male), bulb of vestibule (female) and covering
urethra(in both)
• Ducts of bulbourethral glands(male) greater vestibular glands(female)
• Branches of pudendal nerves and internal pudendal vessels
12/29/18 13
14. Contents of Superficial
Perineal Pouch in Male
1. Root (crura) of the penis and muscle
associated with it (ischiocavenous)
2. Bulbs of the penis and surrounding muscle
(bulbospongiosus)
3. Superficial transverse perineal muscles
4. Branches of the internal pudendal artery
5. Branches of Perineal branch of the
pudendal nerves-
• Posterior scrotal branches
• Transverse perineal branches
6. Perineal branch of posterior cutaneous nerve
of thigh
12/29/18 14
15. Superficial perineal
space(Pouch)
• Anteriorly open and posteriorly
closed by fused perineal
membrane with colles’ fascia
• Space open anteriorly (In rupture
of cavernous part of urethra, urine
can extravasate from scrotum
upward in front of symphysis pubis
into anterior abdominal wall deep
to membranous fascia of Scarpa)
12/29/18 15
16. Contents of superficial perineal
pouch in female
1. Root (crura) of the clitoris and muscle
associated with it (ischiocavenous)
2. Bulbs of the vestibule and surrounding
muscle (bulbospongiosus)
3. Superficial transverse perineal muscles
4. Branches of the internal pudendal artery
5. Branches of Perineal branch of the
pudendal nerves-
6. Posterior labial branches
7. Transverse perineal branches
8. Posterior labial branch
6. Perineal branch of posterior cutaneous
nerve of thigh
7. Greater vestibular glands
12/29/18 16
17. Superficial Transverse Perineal
Muscles
• The superficial transverse perineal
muscles lie in the posterior part of the
superficial perineal pouch
• Each muscle arises from the ischial
ramus and is inserted into the perineal
body
• The function of these muscles is to fix
the perineal body in the center of the
perineum
• All the muscles of the superficial
perineal pouch are supplied by the
perineal branch of the pudendal nerve
12/29/18 17
18. DEEP PERINEAL POUCH
• Lies between superior and inferior
fascia of urogenital diaphragm
• Closed on all sides
• Boundaries
• Above : superior layer of urogenital
diaphragm
• Below : inferior layer of urogenital
diaphragm or perineal membrane
• Infront : transverse ligament of pubis
• Behind : Fusion of both membrane
12/29/18 20
19. Deep perineal space
(Pouch)• Contents
• Membranous urethra(male),urethra and vagina(female)
• Deep transverse perineal muscle, sphincter urethrae
• Bulbourethral gland (male)
• Branches of intenal pudendal vessels(artery of penis)
• Branches of pudendal nerve(dorsal nerve of penis)
12/29/18 21
20. Contents of the Deep Perineal
Pouch in the Male
1. The membranous part of the urethra
2. The sphincter urethrae muscle
3. The bulbourethral glands
4. The deep transverse perineal
muscles
5. The internal pudendal vessels and
their branches
6. The dorsal nerves of the penis
12/29/18 22
21. Contents of deep perineal pouch in
female
1. Proximal part of urethra
2. External urethral sphincter muscle
3. Deep transverse perineal muscles
4. Related vessels and nerves
5. Deep artery of clitoris
6. Dorsal artery of clitoris
7. Artery to bulb of vestibule
8. Urethral artery
9. Dorsal nerve of clitoris
12/29/18
22. Deep Transverse Perineal Muscles
• The deep transverse perineal muscles lie posterior to the sphincter urethrae
muscle
• Each muscle arises from the ischial ramus and passes medially to be inserted
into the perineal body
• These muscles are clinically unimportant
12/29/18 24
23. Sphincter Urethrae Muscle
• The sphincter urethrae muscle surrounds the urethra in the deep perineal
pouch
• It arises from the pubic arch on the two sides and passes medially to encircle
the urethra
• The perineal branch of the pudendal nerve supplies the sphincter
• The muscle compresses the membranous part of the urethra and relaxes
during micturition
• It is the means by which micturition can be voluntarily stopped
12/29/18 26
24. Internal Pudendal Artery
• The internal pudenal artery on
each side enters the deep perineal
pouch and passes forward, giving
rise to:
• The artery to the bulb of the penis
• The arteries to the crura of the
penis
• The dorsal artery of the penis,
which supplies the skin and fascia
of the penis
12/29/18 27
25. Bulbourethral Glands
• The bulbourethral glands are two
small glands that lie beneath the
sphincter urethrae muscle
• Their ducts pierce the perineal
membrane and enter the penile
portion of the urethra
• The secretion is poured into the
urethra as a result of erotic
stimulation
12/29/18 28
26. Muscle Origin Insertion Nerve Supply Action
Bulbospongiosus Fascia of bulb of
penis and corpus
spongiosum and
cavernosum
Perineal body Perineal branch of
pudendal nerve
Compresses urethra
and assists in
erection of penis
Ischiocavernosus Ischial tuberosity Fascia covering
corpus cavernosum
Perineal branch of
pudendal nerve
Assists in erection of
penis
Sphincter urethrae Pubic arch Surrounds urethra Perineal branch of
pudendal nerve
Voluntary sphincter of
urethra
Superficial transverse
perineal muscle
Ischial tuberosity Perineal body Perineal branch of
pudendal nerve
Fixes perineal body
Deep transverse
perineal muscle
Ischial ramus Perineal body Perineal branch of
pudendal nerve
Fixes perineal body
Male Urogenital Muscles
12/29/18 29
27. Muscle Origin Insertion Nerve supply Action
Bulbospongiosus Fascia of corpus
cavernosum
Perineal body Perineal branch of
pudendal nerve
Sphincter of
vagina and
assists in
erection of clitoris
Ischiocavernosus Ischial tuberosity Fascia covering
corpus
cavernosum
Perineal branch of
pudendal nerve
Causes erection
of clitoris
Sphincter urethrae Pubic arch Surrounds urethra Perineal branch of
pudendal nerve
Voluntary sphincter
of urethra
Superficial transverse
perineal muscle
Ischial tuberosity Perineal body Perineal branch of
pudendal nerve
Fixes perineal body
Deep transverse
perineal muscle
Ischial ramus Perineal body Perineal branch of
pudendal nerve
Fixes perineal body
Female Urogenital Muscles
12/29/18 30
28. Urogenital diaphragm
• Triangular in shape
• Attached laterally to ischiopubic rami
and ischial tuberosities
• Formed by sphincter of urethra,
deep transverse perineal muscle,
superior and inferior fascia of
urogenital diaphragm
12/29/18 31
29. Urogenital diaphragm
• Structures piercing the urogenital
diaphragm
• The urogenital diaphragm is pierced
by urethra in both male and female
and by also by vagina behind the
urethra in female.
12/29/18 32
30. Urogenital diaphragm
• Actions diaphragm:
• It provides support to prostate gland
or the urinary bladder. Sphincter
urethrae exert voluntary control to
micturition. It also constricts the
vagina in female.
12/29/18 33
31. Perineal central tendon
(Perineal Body)
• Wedge-shape fibromuscular mass
• In female, between anal canal and lower
end of vagina,
• In male, between anal canal and root of
penis
• It is larger in the female than in the male
and support to the posterior wall of the
vagina
• It is the point of attachment of many
perineal muscles, including the levatores
ani muscles
• Levatores ani assist the perineal body in
supporting the posterior wall of the
vagina
12/29/18 34
32. The Perineal Body
Structurally perineal body is an irregular fibro muscular mass, containing
both collagenous and elastic fibers and both skeletal and smooth
muscles.
It is the site of convergence of several muscles:
1. Bulbospongiosus,
2. Superficial transverse perinea
3. Deep transverse perinea
4. Sphincter urethrae and
5.Superficial part of external anal sphincter
6. Deep part of external anal sphincter and
7. Levator ani
12/29/18 35
34. Sphincter ani externus
Levator ani
Superficial transverse muscle perineum
Bulbospongiosus
Deep transverse muscles perineum
12/29/18 37
35. Perineal Membrane
• Also called as Inferior fascia of
urogenital diaphragm.
• Situated between superifical and deep
perineal pouch
• Attachments
• Sides : Ischiopubic Ramus
• Anteriorly : Has free margin behind
pubis transverse ligament of pubis
• Posteriorly : Fuses with the transversus
pereni profoundus muscle
12/29/18 38
36. • In Males is pierced by:
• Urethra
• Duct of bulbourethral gland
• Artery & nerve to bulb of penis
• Dorsal & deep artery of penis
• Urethral artery
• Post. scrotal nerve & vessels
• Branches of perineal nerve to
superficial muscles
12/29/18 39
37. • In Females is pierced by:
• Urethra+ vagina
• Artery & nerve to bulb of vestibule
• Dorsal & deep artery of clitoris
• Urethral artery
• Posterior labial nerve & vessels
• Branches of perineal nerve to
superficial muscles
12/29/18 40
38. Pelvic Diaphragm
• The pelvic diaphragm is a muscular partition formed by the levatores ani
and coccygei, with which may be included the parietal pelvic fascia on their
upper and lower aspects.
• It separates the pelvic cavity above from the perineal region below.
• The right and left levatores ani lie almost horizontally in the floor of the
pelvis, separated by a narrow gap that transmits the urethra, vagina, and
anal canal.
• The levator ani is usually considered in three parts:
1.pubococcygeus,
2.puborectalis, and
3. iliococcygeus.
• The pubococcygeus, runs backward from the body of the pubis toward the
coccyx and may be damaged during parturition.
12/29/18 41
55. Applied
• Extravasation of urine is superficial or deep
• Damage to perineal body:prolapse of uterus
• Episiotomy: Median or Mediolateral
• Pudendal nerve block
12/29/18 58
