Unit 2: Lesson 3
Pelvic Floor
H.L. Nashandi
March 2022
Learning Outcomes
At the end of the session the student should be able to:
• Explain the functions of pelvic floor.
• Describe the various muscle layers of the pelvic
floor
PELVIC FLOOR
(Myles 2008:93; Sellers, 2018:128)
• Consists of soft tissues within bony pelvis
• Tissues enclose outlet to pelvis
• Part of birth canal
Functions of pelvic floor
▪ To keep pelvic and abdominal contents in place
including gravid uterus
▪ Allow access to outside for bladder, uterus and rectum
➢through urethra, vagina and anus
▪ Responsible for voluntary control of
➢micturition & defecation
Functions of pelvic floor cont…
▪ Plays important part in sexual intercourse
▪ During childbirth, it influence passive movements of
fetus through birth canal
▪ Relaxes to allow exit of fetus from pelvis
Pelvic floor
Made up of 3 layers of muscles:
1.The deep muscle layer
2. Middle layer
3. Superficial layer
1.The deep muscle layer
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highly specialised
Attached to inner circle of pelvis at front and side.
Inserted into sacrum and coccyx posteriorly.
Attach either side to form a slope downwards and
forwards
• Fetus part which meet pelvic floor first, directed
downward and forward
• Follow axis of pelvis or curve of Carus through birth
canal
• These muscle move fetus through the pelvic canal in
the mechanism of labour.
1.The deep muscle layer cont…
The deep muscle layer:
Composed of Levator ani muscles
▪ Ischiococcygeus (posterior, smaller)
▪ Iliococcygeus (thin, elevator)
▪ Pubococcygeus:
➢Puborectalis
➢Pubovaginalis
➢Pubococcygeus proper
1.The deep muscle layer cont…
• Levator ani muscles maintain constant tone (except during
voiding, defecation and Valsava manoeuvre).
• Made of iliococcygeus and pubococcygeus.
• Highly specialize muscle form a sling around vagina, rectum,
give passage to anal canal, lower third of vagina and urethra.
• Ischiococcygeus and coccygeus originate from rami of the
ischium, white fascia and ischial spines.
Picture of the pelvic floor
Curve of Carus
2.The middle layer
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Strong perineal body
Below levator ani muscle
Make up posterior portion of urogenital triangle.
Mass of interlocking muscular, fascial and fibrous
component.
Lying between the vagina and anorectum.
Integral attachment point for components of the urinary and
fecal continence mechanism.
Has deep transverse perineal muscles
Damaged during vaginal childbirth.
Injury due to spontaneous tear or episiotomy
3. The superficial layer
▪ Superficial area of pelvic outlet.
▪ From symphysis pubis anteriorly – sacrum and
coccyx posteriorly.
▪ Sling enclosed and strengthened by pairs of muscles
interspersed with adipose tissue.
3. The superficial layer cont…
Muscles found in the perineum:
• Ischiocavernosus (from ischial tuberosities to crura of
the clitoris)
• Bulbocavernosus and Superficial transverse perineal
muscle (from inner surface of ischial tuberositiescentral tendon of perineum)
• Lateral episiotomy involves: vaginal epithelium,
transverse perineal muscles, bulbocavernosus muscle
and perineal skin
• Anal sphincter: continuation of bulbocavernosus
Superficial layer
• Study the muscles in detail in your
prescribed book.
• Read about Kegel exercises and practice it.