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Dissection of male pelvis from a lateral approach

Nerve supply to levator ani and coccygeus muscles, medial view

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Image #172-5
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Dissection of male pelvis from a lateral approach
Nerve supply to levator ani and coccygeus muscles, medial view
The prostate has been removed. The superior fascia of the pelvic diaphragm has been dissected to expose the branches from the third and fourth sacral nerves that supply the muscles of the right half of the diaphragm. Note that one nerve (25) passes into the coccygeus muscle and emerges inferiorly on the medial side of the levator ani.
1 . Left pointer: Lateral umbilical ligament (cut off) Right pointer: Superior vesical artery (cut off)
2 . Psoas major muscle
3 . Femoral nerve
4 . Iliacus muscle
5 . Upper pointer: Obturator artery Lower pointer: Obturator nerve
6 . External iliac artery and vein
7 . Lacunar ligament
8 . Superior pubic ramus
9 . Obturator fascia (obturator internus visible deep to fascia)
10 . Pubic symphysis
11 . Levator ani muscle (puborectalis muscle, covered by fascia)
12 . Tendinous arch of pelvic fascia
13 . Internal iliac artery
14 . Lumbosacral trunk
15 . Left pointer: Superior gluteal artery Right pointer: Lateral sacral artery
16 . Sacral nerve I
17 . Left pointer: Internal pudendal artery Right pointer: Inferior gluteal artery
18 . Sympathetic trunk
19 . Sacral nerve II
20 . Sacrum (cut away near midline)
21 . Sacral nerve III
22 . Piriform muscle
23 . Sacrum (dorsal surface)
24 . Upper pointer: Pudendal nerve Lower pointer: Sciatic nerve
25 . Nerve to Levator ani muscle and coccygeus muscle (this branch penetrates muscle, reappearing on the inner surface of the muscle nearly opposite the anal canal)
26 . Nerve to Levator ani muscle
27 . Coccyx
28 . Coccygeus muscle
29 . Location of ischial spine
30 . Anococcygeal ligament
31 . Levator ani muscle (pointer on iliococcygeus muscle)
32 . Levator ani muscle (pointer on pubococcygeus muscle)
33 . Tendinous arch of levator ani muscle (not clearly defined in this specimen)
34 . Anal canal
35 . Urogenital diaphragm
36 . Urethra