Describe Perineal Body Flashcards

Tendinous junction for muscles and other structures in the perineum. Attaches to the posterior margin of the perineal membrane, and lies between the ischial tuberosities.

As the urogenital septum reaches the cloacal membrane the labioscrotal folds fuse posteriorly forming the perineal body, which separates the urogenital membrane from the anal membrane.

External anal sphincter muscle
Bulbuspongiosus muscle
Superficial transverse perineal muscle
Deep transverse perineal muscle
Levator ani
External urinary sphincter

Muscles pull the perineal body in different directions at different angles, resulting in elevation of the pelvic floor. Essential for integrity of the pelvic floor.

Planned surgical incision into the perineum at the vaginal vestibule, can be made midline or at an angle. Made to allow the head of the fetus to pass through the vagina if a perineal tear is likely. It is performed under local pudendal anesthesia and is sutured closed after birth.

Below the pelvic diaphragm (levator ani) in the perineum, only within the urogenital triangle. Free posterior border anchored by the perineal body, attaches laterally to the ischiopubic rami and anteriorly to the inferior pubic ligament.

Erectile tissues anchored to superficial surface, covers hiatus in the levator ani but is still perforated to allow the urethra and vagina (in women) to pass through.

The deep perineal space is located between the perineal membrane and the pelvic diaphragm.

Deep transverse perineal muscle - fixes and stabilizes perineal body External urethral sphincter - encircles and constricts urethra Compressor urethrae muscle - found in close association with the sphincter urethrovaginalis muscle in females, supports urethral and vaginal constriction All muscles innervated by the deep branch of the perineal nerve (branch of the pudendal nerve)

Superficial transverse perineal muscle - fixes and stabilizes the perineal body, attaches to the ischial rami and tuberosities laterally Bulbospongiosus muscle - compresses the bulb of penis or the bulbs of vestibule, also constricts the vaginal orfice or the spongy urethra Ischiocavernosus muscle - compresses the corpus cavernosum

Female
Two crura of the clitoris - attached to ischiopubic rami, become corpora cavernosa, covered by ischiocavernosus muscles Two bulbs of the vestibule - surround the urogenital openings, firmly attached to the perineal membrane, covered by bulbospongiosus muscle
Male
Two crura - attached to ischiopubic rami, become corpora cavernosa, covered by ischiocavernosus muscles Bulb of the penis - attached to perineal membrane, becomes corpus spongiosum, covered by bulbospongiosus muscle

Space between the legs and below the true pelvis, separated from pelvis by pelvic diaphragm. Contains external genitalia and external outlets of the anus and urethra (and vagina in women) as well as associated nerves, blood vessels, and fascia. Anterior boundary – pubic symphysis
Posterior boundary – coccyx
Lateral boundaries – ischial tuberosities
Anterolateral boundaries – ischiopubic ramus
Posterolateral boundaries – sacrotuberous ligament

Anterior portion of the perineum, contains scrotum and bulb of the penis in males, and opening of the vagina, clitoris, and external urethra in females. Contains Colle’s fascia deep to the skin and fatty Camper’s fascia. Colle’s fascia is continuous with Scarpa’s. Anterior boundary - pubic symphysis
Anterolateral boundary - ischiopubic rami
Posterior boundary- superficial transverse perineal muscle/line between the ischial tuberosities

Area of perineum posterior to the urogenital triangle, contains anus (and the external anal sphinchter), bounded posteriorly by the coccyx and anterolaterally by the ischial tuberosities.

Triangular fibrous membrane separating deep and superficial perineal pouches. Attaches laterally to the inferior ischiopubic rami, separated anteriorly from the pubic symphisis by an opening for the deep dorsal vein of the penis in males. Continuous with Colles’ and pelvic fascia as it connects to perineal body.

Perforated by the urethra, ducts of the bulbourethral glands, arteries to the bulb, deep arteries to the penis, and dorsal arteries and nerves of the penis.

Urethra, deep dorsal nerve, artery and vein of the clitoris, vagina, artery to bulb of vestibule, pudendal nerve and arteries, and the perineal nerve and arteries.