Pelvic Floor Anatomy by Prof. Shagufta Tahir

1. by
Prof. Dr. Shagufta Tahir

2. FEMALE PELVIS
 The pelvis is the basin formed by muscles.
 The back wall is formed by the sacrum centrally &
piriformis muscle laterally, the side walls are the right
& left obturator internus muscles. The front wall is
formed by symphysis pubis.
 The floor is formed by the levator ani muscles & the
coccygeus muscles covering the sacrospinous
ligaments.

3. Tip of Coccyx
Ant. Sup. Iliac Spine
Pubic symphysis
1. Identify the bony walls and ligamentous landmarks of the pelvis.
Sacrotuberous Ligament
Sacrospinous Ligament
Sacrospinous
Ligament
Sacrotuberous Ligament
Lesser
Sciatic
Foramen
Greater
Sciatic
Foramen
Iliopectineal Line
Coccyx
Pubic SymphysisPubic Arch
Ischial Tuberosity
Sacrotuberous
Ligament
Pelvic
Outlet

4. Pelvic floor
 The priformis muscle courses from upper ½ of the
sacrum straight outwards to the greater siaciatic
foramen, to insert to the greater trochanter of the
femur.
 The obturator internus muscle origintes from the
bony edges of the obturator foramen and the entire
inner surface of the obturator membrane to form a
wide, fan shaped muscles. this muscle tappers into
strong tendon, which then turns 120 degree to exit
the pelvis through the lesser sciatic foramen to
insert on to the greater trochanter with the
piriformis tendons.

5. Pelvic floor
 The pelvic floor is also called pelvic diaphragm
through which traverses urethra, the lower 1/3rd of
vagina and the anal canal.
 These pass through levator hiatus or central
opening between levator ani muscles of the pelvic
diaphragm, passively resting on top of the
posterior portion of the levator ani muscles named
levator plates, are the upper 2/3rd of the vagina &
rectum.
 Just below or inferior to the pelvic diaphragm is
the perineum anteriorly and ischio-rectal fossa
posteriorly.

7. Applied Anatomy
 Musculo-tendineous sheath that spans the pelvic
outlet…. Paired levator ani
 Fasciae investing the muscles are continuous with
visceral pelvic fascia above, perineal fascia below and
obturator fascia laterally.
 The pelvic floor support urogenital organs & ano-
rectum.

8. PELVIC DIAPHRAGM
 The floor is formed by upper surface of levator
ani complex of muscles & coccygeus muscles.
 The coccygeus muscle is very thin, non-
functional covering of strong sacro-spinous
ligament.
 Levator ani- 3 parts, pubo-coccygeus, pubo-
rectalis arise from back of the body of pubic
bone anterior part of the obturator internus
muscle. These muscles make levator hiatus
through which traverses urethera, lower 1/3rd
of vagina and anal canal.

9. PELVIC DIAPHRAGM
 Pubo-coccygeus surrounds lower 1/3rd of vagina &
inserts in to the apex of the perineal body b/w
vagina & ano-rectal junction.
 Pubo-rectalis is medial & inferior portion of the
pubo-coccygeus muscle & meet with its counter
part behind ano-rectal junction.
 The pubo-rectalis form right angle of the ano-
rectal junction, which helps in maintenance of
fecal continence.

10. 4. Identify the pelvic diaphragm and its components
Sacrum
Pubic Symphysis
Urethra
Rectum
Obturator
Internus
Coccyx
Coccyx
Pubic Symphysis
Levator Prostatae or
Sphincter Vaginae
Puborectalis
Perineal
Body
Iliococcygeus
Coccygeus
Inferior ViewSuperior View
Sphincter Vaginae (or
Levator Prostatae)
Puborectalis
Pubococcygeus
Iliococcygeus
Coccygeus
Pubococcygeus
Vagina

11. Applied Anatomy of pelvic floor
 Supplied on superior surface by saceral nerve roots
( S2-S4), on inferior surface by the perineal branch
of pudendal nerve. It has 3 parts according to its
attachments ilio-coccygeus, pubo-coccygeus &
ischio-coccygeus.
 Pubococcygeus divide in case of female into
pubovaginalis & puborectalis, while in male
pubouretheralis, this muscle also enclose 3 hiatus
in its two arms which are urethra, vagina & rectum.

12. Applied Anatomy of pelvic floor
 Its medial part form a sling around rectum termed
puborectalis,(1) it serve as part of sphincter
mechanism & pelvic floor (2) its U-shaped sling
pulls ano-rectal junction anteriorly towards pubis,
resulting an angulation between rectum & anal
canal called anorectal angle, probably this also
help in maintaining continence.
 Anterior fibers of levator ani decend upon vagina
in women termed as pubo-perineal muscle, they
have been found damaged in women with urinary
incontinence & pelvic organ prolapse after delivery.

13. Superficial muscles showing deeper
structures

14. Superficial perineal muscles
 Perineum is divided into 2 parts: urogenital triangle &
anal triangle.
 The urogenital triangle has two layers of muscles,
superficial & deep muscles, the boundry b/w two is
tough perineal membrane.
 The superficial compartment contains tranversus
perinei, bulbocavernosis & ishciocavernosis,
innervated by pperineal branches of pudendal nerve.


15. Superficial perineal muscles
 Deep compartment muscles are related to urinary
incontinence, compressor urethra & urethrovaginal
muscles. These muscles run over lower 1/3rd of urethra
& are part of external urethral sphincter make
urethrovesical junction down to perineal membrane.
 All of them innervated by perineal branches of
pudendal nerve.

16. Superficial muscles of pelvic floor

17. PERINEAL BODY
 Anchoring urogenital & anal triangle the perineal
body is centrally located, found b/w vaginal
introitus & the anus. Lower 1/3rd is fused with
perineal body, while perineal body is anteriorly
fused with vagina.
 The square based perineal body is 1 cm x 2 cm
above or superior to the leval of ischial tuberosity.
 The apex of perineal body shapped like pyramid, is
located at junction of lower 1/3rd with upper 2/3rd
of the vagina with the middle one third.

18. 2. Identify the normal position and anatomical
relationships of the pelvic viscera
Anteverted Anteflexed

19. Pelvic connective tissue support
 Level I : Cardinal ligaments & uterosacral ligaments.
 Level II ; suspend each side of vagina and rectum to
the pelvic side wall.
 Level III: fusion of lower 1/3rd of vagina and anal canal
with the pubococcygeus muscles & perineal body.
Secures the vertical orientation of urethra, vagina &
rectum in women while standing.

20. TERMINAL BRANCHES OF PUDENDAL NERVE

22. Anal sphincter Complex
 It consists of EAS & IAS separated by conjoint
longitudinal coat . They form single unit but
anatomically & physiologically are very distinct
from each other.
 Surgical anal canal -4cm from verge to anorectal
ring.
 Proximal canal lined by columnar epithelium
arranged in columns called morgagni—branch of
superior rectal artery supply each of them.

23. Anal sphincter Complex
 3 anal cushions keep continence of flatus & liquid
stool- these are terminal radical of superior rectal
artery & vein. The vessels are largest in the left-
lateral, right-posterior & right- anterior quadrant
of the anal canal.
 Dentate line- 2cm above verge anal valves create
demarcation.
 Ano-derm covers 1-1.5 cm below dentate line-
squamous epithelium supplied with somatic
nerves.

26. Anatomy of EAS & IAS
 EAS : sub-divided into 3 parts, subcutaneous,
superficial & deep.
 EAS is shorter anteriorly in females, deep EAS is
intimate with pubo-rectalis, the sub-cutaneous
part is circular may have attachment with perineal
body anteriorly & ano-coccygeal ligament
posteriorly.
 IAS: is thickened continuation of circular smooth
muscles of bowel and ends with the well defined
round edge 6-8 mm above the anal margins at the
junction of superficial & subcutaneous part of the
EAS.
 IAS: It is pale in appearance to naked eye.