Dissection of muscles of male perineum and pelvic diaphragm

Muscles of urogenital diaphragm

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Image #174-4
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Dissection of muscles of male perineum and pelvic diaphragm
Muscles of urogenital diaphragm
The inferior fascia of the urogenital diaphragm has been removed to reveal the sphincter of the urethra within the deep perineal space. There was no evident deep transverse perineal muscle on either side of this specimen. The bulbourethral gland has been excised. Muscle fibers (4, lower pointer) that are directed posteriorly toward the central point of the perineum were found to be continuous with fibers of the superficial transverse perineal muscle on the left.
1 . Penis (sectioned)
2 . Dorsal vein of the penis
3 . Upper pointer: Dorsal nerve of the penis Lower pointer: Dorsal artery of penis
4 . Upper pointer: Sphincter muscle of urethra Lower pointer: Muscle fibers within urogenital diaphragm that pass medially towards central tendinous point of perineum
5 . Penis artery
6 . Superior fascia of urogenital diaphragm
7 . Obturator fascia
8 . Obturator internus muscle
9 . Ischial tuberosity
10 . Fibers of levator ani muscle passing to tissue alongside anus
11 . Levator ani muscle
12 . Pubic arcuate ligament
13 . Transverse perineal ligament
14 . Membranous part of urethra (cut off at lower surface of urogenital diaphragm)
15 . Obturator membrane
16 . Posterior border of obturator foramen
17 . Sacrotuberous ligament
18 . External anal sphincter muscle
19 . Anus
20 . Anococcygeal ligament
21 . Coccyx