Perineal membrane

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Perineal membrane
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Coronal section of anterior part of pelvis, through the pubic arch. Seen from in front. (Inferior layer labeled at bottom left.)
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Median sagittal section of pelvis, showing arrangement of fasciæ. (Inferior layer labeled at center left.)
Details
Location Perineum
Identifiers
Latin membrana perinei
TA98 A09.5.03.002
TA2 2444
FMA 30514
Anatomical terminology

The perineal membrane is an anatomical term for a fibrous membrane in the perineum. The term "inferior fascia of urogenital diaphragm", used in older texts, is considered equivalent to the perineal membrane.

Contents

It is the superior border of the superficial perineal pouch, and the inferior border of the deep perineal pouch.

Structure

The perineal membrane is triangular in shape. [1] It attaches to both ischiopubic rami of the pelvis. It also attaches to the perineal body. It is about 4 cm. in depth.[ citation needed ]

Its apex is directed forward, and is separated from the arcuate pubic ligament by an oval opening for the transmission of the deep dorsal vein of the penis or the deep dorsal vein of the clitoris.

Its lateral margins are attached on either side to the inferior rami of the pubis and ischium, above the crus penis.

Its base is directed toward the rectum, and connected to the central tendinous point of the perineum. The base is fused with both the pelvic fascia and Colle's fascia.

Relations

It is continuous with the deep layer of the superficial fascia behind the superficial transverse perineal muscle, and with the inferior layer of the diaphragmatic part of the pelvic fascia.

Perforations

In males, it is perforated, about 2.5 cm below the pubic symphysis, by the urethra, the aperture for which is circular and about 6 mm in diameter, by the arteries to the bulb, and the ducts of the bulbourethral glands close to the urethral orifice; by the deep arteries of the penis, one on either side close to the pubic arch, and about halfway along the attached margin of the fascia; by the dorsal arteries and nerves of the penis near the apex of the fascia. Its base is also perforated by the perineal vessels and nerves, while between its apex and the arcuate pubic ligament the deep dorsal vein of the penis passes upward into the pelvis.

Contents

If the inferior fascia of the urogenital diaphragm is detached on either side, the following structures will be seen between it and the superior fascia:

Additional images

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The vaginal support structures are those muscles, bones, ligaments, tendons, membranes and fascia, of the pelvic floor that maintain the position of the vagina within the pelvic cavity and allow the normal functioning of the vagina and other reproductive structures in the female. Defects or injuries to these support structures in the pelvic floor leads to pelvic organ prolapse. Anatomical and congenital variations of vaginal support structures can predispose a woman to further dysfunction and prolapse later in life. The urethra is part of the anterior wall of the vagina and damage to the support structures there can lead to incontinence and urinary retention.

References

PD-icon.svgThis article incorporates text in the public domain from page 428 of the 20th edition of Gray's Anatomy (1918)

  1. Peschers, U; DeLancey, J. O. L. (2007). J. Laycock, J. Haslam (ed.). Therapeutic Management of Incontinence and Pelvic Pain: Pelvic Organ Disorders (2 ed.). London: Springer. pp. 9–20.