1. Muscles and Fascia of Pelvic Wall
Dr. Sama-ul-Haque
Dr. Safa Ahmad
Dr. Rania Gabr

2. Objectives
Describe the origin, insertion, nerve supply and actions of the Piriformis, obturator internus & levator ani.
Describe the pelvic fascia organization.

3. Pelvic Walls 2-Obturator internus muscles: Anterior pelvic wall:
Formed primarily by the 1-bodies and 2-rami of
the pubic bones and the3- pubic Symphysis
Lateral pelvic walls:
Formed by 1- the hip bones; and the
2-Obturator internus muscles:
Origin: Proximal surface of the ilium & ischium;
obturator membrane
Insertion: Greater trochanter of the femur

4. Nerve supply:
N to Obturator internus ( L5, S1, S2)
Action:
Lateral Rotation of the thigh

5. Pelvic Walls Posterior Pelvic Wall:
Formed by the sacrum, coccyx, adjacent parts of the ilia, Sacroiliac joints and
Piriformis muscle:
Origin: 1-Pelvic surface between 2nd and 4th sacral segments, 2-superior margin of the greater sciatic notch and 3-sacrotuberous ligament.
Insertion: Greater trochanter of femur

6. Pelvic Floor Formed by the funnel shaped pelvic diaphragm
Consists of the levator ani and coccygeus
muscles and their fascia
Stretches between the pubis anteriorly and the coccyx posteriorly and from one lateral pelvic wall to the other.

7. Levator Ani Three parts Pubococcygeus Puborectalis Iliococcygeus
Origin:
Collectively they run from the
1- body of thepubis,
2-the tendinous arch of the obturator
fascia and
3-the Ischial spine.
Insertion: To the
1- perineal body,
2-the coccyx,
3- the anococcygeal ligament,
4- the walls of the prostate or vagina, the rectum and the anal canal

8. Pelvic Diaphragm

9. Levator Ani Nerve supply: Nerve to levator ani (S4) Pudendal nerve
Action:
1- Forms most of the pelvic diaphragm that helps to support the pelvic viscera;
2- Acting together they raise the pelvic floor and 3- Assist the abdominal muscles in forced expiration activities.

10. Pelvic Floor (Male)

11. Pelvic Walls

12. The anteroinferior pelvic wall:
Is formed primarily by the
1- bodies and
2- rami of the pubic bones and the
3-pubic symphysis.
Participates in bearing the weight of the urinary bladder.

13. The lateral pelvic walls:
- Have a bony framework formed by the hip bones, including the obturator foramen ; which is closed by the obturator membrane.
Are covered and padded by the obturator internus muscles .
Each obturator internus passes posteriorly from its origin within the lesser pelvis, exits through the lesser sciatic foramen, and turns sharply laterally to attach to the femur.

14. The posterior pelvic wall:
Consists of a bony wall and roof in the midline (formed by the sacrum and coccyx) and musculoligamentous posterolateral walls (formed by the :
1-sacroiliac joints and their
2-associated ligaments and
3- piriformis muscles).
Each piriformis muscle leaves the lesser pelvis through the greater sciatic foramen to attach to the femur .
Is the site of the nerves forming the sacral plexus; the piriformis muscles form a muscular bed for this nerve network

15. Pelvic Floor (Male)

16. Pelvic Floor (Female)

17. Female Pelvic Floor (Medial view)

18. Perineal Body

19. Coccygeus Muscle Origin: Ischial spine Insertion:
Lower end of the sacrum and coccyx
Nerve supply:
Branches of S4 and S5
Action:
Forms a small part of the pelvic diaphragm
that supports the pelvic viscera, flexes the
coccyx.

20. Pelvic Fascia

21. Pelvic Fascia Pelvic fascia Lines the pelvic walls
Surrounds the bases of the pelvic viscera,
Forms sheaths around blood vessels and nerves that course medially from the pelvic walls to reach the viscera in the midline.
This pelvic fascia is a continuation of the extraperitoneal connective tissue layer found in the abdomen.

22. 1- Membranous pelvic fascia:
Parietal and visceral
2- Endopelvic fascia:
Loose and condensed

23. Pelvic Fascia

24. Female
Rectovaginal septum separates the posterior surface of the vagina from the rectum
Condensations of fascia form ligaments that extend from the cervix:
1- Pubocervical ligament
2- Transverse cervical or (cardinal ligament),
3- Uterosacral ligament.

25. Male
Condensation of fascia around the anterior and lateral region of the prostate (prostatic fascia)
Rectovesical septum, which separates the posterior surface of the prostate and base of the bladder from the rectum.

26. Thank you