The pelvic diaphragm is formed by the levator ani and coccygeus muscles on both sides. It separates the pelvis from the perineum. The levator ani has three parts: the pubococcygeus, iliococcygeus, and ischiococcygeus. The pubococcygeus has anterior, middle, and posterior fibers that surround structures like the prostate, vagina, and anus. The levator ani and coccygeus close the pelvic outlet and support pelvic organs. They also help maintain continence during actions like coughing and prevent prolapse. The muscles are innervated by sacral nerves and help with functions

2. Pelvic Diaphragm
 Levator Ani and coccygeus of both the
side combinely forms pelvic diaphram
 Diaphram seperates the pelvis from
perineum
 These is devided into 3 parts
◦ Pubococcygeus
◦ Iliococcygeus
◦ Ischicoccygeus [coccygeus]

5. Pubococcygeus part
 Having three parts of fibers
◦ Anterior fibers
◦ Middle fibers
◦ Posterior fibers

6. Anterior fibers
◦ Arise from medial part of the pelvic
surface of the body of the pubis
◦ In male
 Fibers closely surround the prostate known as
levator prostate
◦ In female
 these fibers are arround the vagina and forms
the sphincter vagina
 In both cases anterior fibers inserted
into perineal body

9. Middle fibers
 The middle fibres constitute the
puborectalis.
 These arise from the lateral part of the
pelvic surface of the body of the pubis.
 They form a loop arround the
anorectal junction
 In female anterior portion of
puborectalis is shorter

10.  The posterior fibres of the
pubococcygeus arise from the anterior
half of the white line on the obturator
fascia. These get attached to
anococcygeal ligament and tip of
coccyx

14. Iliococcygeus Part
 The fibres of this part arise from:
◦ The posterior half of the white line on the
obturator fascia; and
◦ The pelvic surface of the ischial spine.
 They are inserted into the
◦ anococcygeal ligament and into the side
of the last two pieces of coccyx.

16. The Coccygeus
 This muscle represents
◦ the posterior or ischiococcygeus part of the
pelvic diaphragm.
 It is triangular in shape.
 It is partly muscular and partly tendinous.
 Its fibres arise from
◦ (a) The pelvic surface of the ischial spine,
and
◦ (b) the sacrospinous ligament.
 It is inserted into the side of the coccyx,
and into the fifth sacral vertebra

21. Nerve Supply
 The levator ani is supplied by
◦ (1) a branch from the fourth sacral
nerve;
◦ (2) a branch either from the inferior
rectal nerve, or from the perineal
division of the pudendal nerve.
 The coccygeus is supplied by a
branch derived from the fourth and
fifth sacral nerves.

22. Actions of Levators Ani and
Coccygeus
 The levatores ani and coccygeus close the
posterior part of the pelvic outlet.
 2. The levators ani fix the perineal body and
support the pelvic viscera.
 3. During coughing, sneezing, lifting and
other muscular efforts, the levators ani and
coccygei counteract or resist increased intra-
abdominal pressure and help to maintain
continence of the bladder and the rectum.

23.  In micturition, defaecation and parturition,
a particular pelvic outlet is open,
 but contraction of fibres around other
openings resists increased intra-abdominal
pressure and prevents any prolapse
through the pelvic floor.
 The increase in the intra-abdominal pressure
is momentary in coughing and sneezing and
is more prolonged in yawning, micturition,
defaecation and lifting heavy weights.
 It is most prolonged and intense in
second stage of labour.

24.  The coccygei pull forwards and
support the coccyx, after it has
been pressed backwards during
defaecation or parturition or child-
birth

25. Relations of the Levator Ani
 The superior or pelvic surface is
covered with pelvic fascia which
separates it from the bladder, the
prostate, the rectum and the
peritoneum.
 2. The inferior or perineal surface is
covered with anal fascia and forms the
medial boundary of the ischiorectal
fossa.

26.  3. The anterior borders of the two
muscles are separated by a triangular
space for the passage of the urethra
and the vagina.
 4. The posterior border is free and
lies against the anterior margin of
the coccygeus

27.  evolution, the muscles have been
modified to form the pelvic diaphragm
which supports the viscera
 . Such support became necessary
with the adoption of the erect
posture by man.

28. CLINICAL ANATOMY
 The muscles of the pelvic floor may be
injured during parturition
 . When the perineal body is torn, and
has not been repaired satisfactorily,
the contraction of anterior fibres of
the levator ani increases the normal
gap in the pelvic floor, instead of
decreasing it.
 This results in abnormalities like
cystocoele, or prolapse of the
uterus.

29. MCQ
1. Part of the pelvic diaphram are all
except
a) Pubococcygeus
b) Iliococcygeus
c) Ishiococcygeous
d) Piriformis
2. Levator ani is supplied by
a) Branch from forth sacral nerve
b) Branch from the inferior rectal nerve
c) Both of them
d) None of them

30. 3. which of the following is not true about
the relations of levator ani
a) Posterior border is lies against coccygeus
b) Anterior borders are joined with each other
c) Inferiorly covered with anal fascia
d) Superior is covered with pelvic fascia
4. Pelvic diaphram helps in all the actions
except
a. Prolapse of uterus
b. Micturation, Defecation
c. Parturation
d. Lifting heavy wight

31. 5.Branch of the posterior devision of the
internal iliac artery
a) Superior gluteal artery
b) Inferior gluteal artery
c) Superior vesical artery
d) Middle rectal artery

32. Neurourol Urodyn. 2015 Sep 28. doi: 10.1002/nau.22891•Xicohténcatl-
Rugerio
I1, Corona-
Quintanilla
DL2, Nicolás
L2, Martínez-
Gómez
M2,3, Cuevas
E2, Castelán
F2, Rodríguez
-Antolín J2.
The role of
the
pubococcyg
eus muscle
in the
urethrogenit
al reflex of
male rats.
To determine
the response
of the
pubococcyge
us muscle
(Pcm) during
the
urethrogenital
reflex (UGR).
The Pcm is
innervated by
the caudal
branch of the
somatomotor
branch of
the pelvic ner
ve. The
electrically
induced
contraction of
the Pcm
increased the
UP. The
mechanical
stimulation of
the urethra
during the
induced
micturition
caused the
reflex activity
of the Pcm.
Our results
suggest that
the activation
of the Pcm is
relevant for
the UGR in
male rats.
Neurourol.
Urodynam. ©
2015 Wiley
Periodicals,
Inc.