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ANATOMY OF THE
FEMALE PELVIC FLOOR
AND PERINEUM
Dr. A. O. FAWOLE
DEPT. OF OB-GYN
UCH
Pelvic Floor and Perineum
 Anterior perineum
 Posterior perineum
 Pelvic Floor
Perineum
 Borders of pelvic outlet
 Anteriorly – ischiopubic rami
 Posteriorly – coccyx and sacro-tuberous
ligament
 Division (ischial tuberosities)
 Anterior perineum (urogenital triangle)
 Posterior perineum (anal triangle)
 Structures overly perineal membrane
Anterior Perineum
Structures of the Vulva
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Mons
Labia
Clitoris
Vestibule
Erectile structures
Vulva
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Mons
 Hair-bearing skin
 Cushion of adipose tissue
 Labia majora
 Hair-bearing skin
 Termination of round ligaments of uterus
 Labia minora
 Hairless skin fold
 Lacks bed of adipose tissue
 Forms prepuce/frenulum of clitoris
Glands of the vulva
 Labia majora – sebaceous gland
 Sweat glands
 Bartholin’s glands
Superficial compartment
Space between subcutaneous tissues and
perineal membrane
 Clitoris
 Crura
 Vestibular bulb/Bartholin’s gland
 Ischicavernosus (from ischial tuberosity)
 Bulbospongiosus (from perineal body)
 Superficial transverse perineal muscle
 Muscles contained in superficial perineal
pouch
The Perineal Membrane
 Triagular sheet in anterior half of pelvic
outlet
 Dense fibromuscular tissue
 Previously called urogenital diaphragm
 Functions
 Supports pelvic floor
 Counteracts effects of raised intra-abdominal
pressure
 Counteracts effects of gravity
The Perineal Membrane
 Complete sheet in males
 Arises from ischiopubic rami
 Attachments
 Urethra
 Vagina
 Perineal body
 Limits downward descent
Perineal Body
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Mass of connective tissue
Synonym: central tendon of the perineum
Located between vagina and anus
Attachments
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Perineal membrane
Superficial transverse perineal muscle
Bulbospongiosus
Levator ani
Coccyx (via external anal sphincter)
Posterior Perineum
Posterior triangle
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Anus
Anal sphincter
Levator ani
Ischio-rectal fossa
Ischio-rectal fossa
 Lateral - Pudendal vessels/nerve
(Pudendal canal)
 Medial – Fascial covering of levator
ani/external anal sphincter
 Posterior – sacrotuberous ligament
 Anterior – urogenital perineum
 Floor – skin/ subcutaneous fat
Pudendal Nerve/Vessels
 Similar channels
 Nerve arises from sacral plexus (S2- S4)
 Sensory
 Motor
 Artery: anterior division of internal iliac
artery
 Branches
 Clitoral
 Perineal (largest branch: muscles/skin)
 Inferior rectal
Anal Sphincter
 External anal sphincter
 Superficial portion
 Deep portion
 Internal anal sphincter
 Thickening of circular smooth muscle of
anal wall
 Important during repair of third
(fourth) degree perineal laceration
The Pelvic Floor
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Demands of upright posture
Support for pelvic structures
Passage of fetus
Openings for waste elimination
Fibromuscular floor
 Visceral ligaments/fascia
Levator ani/Pelvic Wall
 Levator ani most important muscle
 Pubo-rectal
 Pubo-coccygeal
 Coccygeal
 Origin: Posterior aspect of pubic bone, fascia
of pelvic side wall, ischial spine
 Insertion: Perineal body, anal sphincter,
coccyx
 Constitute pelvic diaphragm
 Surfaces covered by fascia
Pelvic Floor
 Pubo-rectal and pubo-coccygeal most
medial
 Pelvic diaphragm forms U-shaped
layer of muscle
 Opening end of U directed anteriorly
(urogenital sinus)
 Urethra
 Vagina
 rectum
Pelvic supports
 Condensations of connective tissue or
endopelvic fascia
 Cardinal ligament
 Uterosacral ligament
 Pubocervical fascia
Clinical significance
Prolapse of pelvic structures
 Damage
 Weakness
Cardinal ligament
Transverse cervical/Mackenrodt’s
ligament
 Attaches lateral cervix/upper vagina
to pelvic side wall
 Connective tissue/involuntary muscle
 Ureter in upper part
Uterosacral ligament
 Postero-lateral attachment of lateral
vaginal fornix/cervix/isthmus to
sacro-iliac joint/third piece of sacrum
Pubo-cervical fascia
 Extends between cardinal ligament
and pubis
 Lateral to the bladder
 Significant in repair operation for
cystocoele (anterior colporrhaphy)