Perineum
Dept. of Human Anatomy
Zhou Hong Ying
OUTLINE
▪ Subdivision
▪ The Layers
▪ Urogenital Diaphragm
▪ Main Structures inside
Superficial & Deep
Perineal Spaces
▪ Ischioanal Fossa
Perineum
A narrow region
Urogenital Triangle
Anal Triangle
Urogenital triangle
3 layers 2 spaces:
Superficial perineal fascia
superficial perineal space
Inferior fascia of urogenital diaphragm
deep perineal space
superior fascia of urogenital diaphragm
Superficial fascia of the urogenital triangle
CLINICAL NOTE
Rupture of the Intermidate Part of the Urethra
Perineal membrane
▪ the lateral margins of UG
diaphragm are ischiopubic rami
The Perineal Body
CLINICAL NOTE
Tear of Perineum & Pubococcygeus
Overview of the Structures inside the Urogenital Triangle
▪ urogenital canals & their sphincter muscles
▪ erectile tissues & their associated muscles
▪ accessory genital glands
▪ transverse perineal muscles
▪ terminal branches of internal pudendal a. & pudendal nerve
Structures of Superficial Perineal space
• Root (bulb and crura) of the penis and associated muscles
(ischiocavernosus and bulbospongiosus).
• Proximal (bulbous) part of the spongy urethra.
• Superficial transverse perineal muscles.
• Deep perineal branches of the internal pudendal vessels and
pudendal nerves
• Clitoris and ischiocavernosus.
• Bulbs of the vestibule and surrounding muscle
(bulbospongiosus).
• Greater vestibular glands.
• Superficial transverse perineal muscles.
• Deep perineal branches of the internal pudendal vessels
and pudendal nerves.
Structures of Deep Perineal space
• urethra and the inferior part of the external urethral
sphincter muscle
• Anterior extensions of the ischioanal fat pads
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Intermediate part of the urethra
Deep transverse perineal muscles
Bulbourethral glands
Dorsal neurovascular structures of the
penis
• Proximal part of the urethra
• Deep transverse perineal muscles
• Dorsal neurovascular structures of
the clitoris
Superficial features
Superficial features
superficial perineal space
superficial perineal space
superficial perineal space
deep perineal space
deep perineal space
deep perineal space
Oblique Coronal Section
through the Prostate
Superficial & Deep
Perineal Spaces
Oblique Coronal Section
through the Vagina
Anal triangle
• Anal canal
Anal sphincter
• Ischioanal fossa Pudendal canal
CLINICAL NOTE
Abscess in the Ischioanal Fossae
▪ The anal mucosa can be easily injured, may be easily torn
by hard feces. Patients develop inflammation and
infection of the anal canal, which can spread into the
ischio-anal fossae.
The Anterior Recess of Ischioanal Fossa & Deep Perineal Space
Pudendal Canal
Anal Sphincter
Pudendal nerve
Arterial Supply of the Perineum
▪ internal pudendal artery (arises from anterior trunk of internal iliac artery)
- dorsal neurovascular structures of penis or clitoris
▪ external pudendal artery (arises from femoral artery)
Review of the Layers
of the Perineum
pelvic diaphragm (levator ani and coccygeus muscles), forming the floor
of the pelvic cavity and the roof of the perineum. The urethra (and
vagina in females) and rectum pass through the urogenital hiatus of the
pelvic diaphragm
Review of the Layers
of Perineum
The external urethral sphincter and deep transverse perineal
muscle span the region of the urogenital hiatus, which is closed
inferiorly by the perineal membrane extending between the
ischiopubic rami
Review of the Layers
of Perineum
Inferior to perineal membrane, the superficial perineal pouch or
space contains the erectile bodies and the muscles associated with
them
Review of the Layers
of Perineum
Subcutaneous Layer
Review of the Layers
of Perineum
Surface Anatomy
▪ in maternity department, to
obstetrician, the perineum
is restricted to the area
between vagina and anus.