Anatomy Question And Answers<\/a><\/strong><\/p>\nPerineum Boundaries:<\/strong><\/p>\n\n- Perineum Superficial:<\/strong>\n
\n- Anterior:<\/strong> Scrotum in the male and mons pubis in the female.<\/li>\n
- Posterior:<\/strong> Buttocks.<\/li>\n
- On each side:<\/strong> Upper part of the medial aspect of the thigh.<\/li>\n<\/ul>\n<\/li>\n
- Perineum Deep:<\/strong>\n
\n- Anterior:<\/strong> Inferior margin of the pubic symphysis.<\/li>\n
- Posterior: <\/strong>Coccyx.<\/li>\n
- On each side:<\/strong> From before backward, ischiopubic ramus, ischial tuberosity, and sacrotuberous ligament.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n
Perineum Divisions:<\/strong><\/p>\nA transverse line passing through the anterior ends of two ischial tuberosities divides the perineum into two triangular areas:<\/p>\n
\n- Anterior triangle, the urogenital region.<\/li>\n
- Posterior triangle, the anal region.<\/li>\n<\/ul>\n
Perineum Anatomy<\/strong><\/p>\nQuestion 2. Write a short note on the perineal body.\u00a0<\/strong>
\nAnswer:<\/strong><\/p>\nPerineal body:<\/strong><\/p>\n\n- It is a fibromuscular node situated in the midline of the perineum at the junction of urogenital and anal triangles.<\/li>\n
- In the male, it lies close to the bulb of the penis, while in the female it lies between the canal and pudendal cleft. It develops from the tip of the anorectal septum.<\/li>\n<\/ul>\n
Perineal body Formation:<\/strong><\/p>\nIt is formed by 10 muscles: 4 paired and 2 unpaired.<\/p>\n
![\"Perineum](\"https:\/\/anatomystudyguide.com\/wp-content\/uploads\/2023\/08\/Perineum-Perineal-Body.png\")
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\n- Perineal Body Paired:<\/strong>\n
\n- Bulbospongiosus<\/li>\n
- Superficial transverse perineal<\/li>\n
- Deep transverse perinei<\/li>\n
- Levator ani<\/li>\n<\/ul>\n<\/li>\n
- Perineal Body Unpaired:<\/strong>\n
\n- Sphincter ani externus (external anal sphincter)<\/li>\n
- Conjoint longitudinal muscle coat of anal canal<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n
Perineal body Applied anatomy:<\/strong><\/p>\n\n- Damage of the perineal body, viz. during parturition:<\/strong> It weakens the pelvic floor and leads to prolapse of the uterus and vagina.<\/li>\n
- Episiotomy (incision in the posterior vaginal wall):<\/strong> It is given to facilitate childbirth and prevent rupture of the perineal body in primiparous females.<\/li>\n<\/ul>\n
Perineum Anatomy<\/strong><\/p>\nQuestion 3. Write a short note on the perineal membrane.\u00a0<\/strong>
\nAnswer:<\/strong><\/p>\nIt is a strong triangular membrane (fascial sheath) that stretches across the urogenital triangle between the ischiopubic rami at the sides. It intervenes between the deep perineal pouch above and the superficial perineal pouch below, thus forming the inferior boundary of the deep perineal pouch and the superior boundary of the superficial perineal pouch.<\/p>\n
\n- In front, it is thickened to form the transverse perineal ligament and is continuous with the superior fascia of the urogenital diaphragm.<\/li>\n
- Behind, it is fixed to the perineal body in the midline and splits into two layers.<\/li>\n
- The upper layer is continuous with the superior fascia of the urogenital diaphragm, while the inferior layer is continuous as Colles\u2019 fascia.<\/li>\n<\/ul>\n
Question 4. Numerate the structures piercing the perineal membrane<\/strong>
\nAnswer:<\/strong><\/p>\nThe structures piercing the perineal membrane are given in the table<\/p>\n
![\"Perineum](\"https:\/\/anatomystudyguide.com\/wp-content\/uploads\/2023\/08\/Perineum-Male-And-Femal.png\")
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![\"Perineum](\"https:\/\/anatomystudyguide.com\/wp-content\/uploads\/2023\/08\/Perineum-Structure-Of-Male-And-Femal-1.png\")
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Question 5. Write a short note on the urogenital diaphragm<\/strong>
\nAnswer:<\/strong><\/p>\nThe urogenital diaphragm (UD) is a musculofascial partition across the pubic arch below the pelvic diaphragm that separates the true pelvic cavity from the anterior part of the pelvic outlet.<\/p>\n
Perineum Anatomy<\/strong><\/p>\nUrogenital Formation:<\/strong><\/p>\n\n- It is a triangular muscle sheet formed by the sphincter urethrae and deep transverse perineal muscles.<\/li>\n
- On the deeper aspect, it is covered by a thin layer of endopelvic fascia called the superior fascia of the urogenital diaphragm, and on the superficial aspect.<\/li>\n
- It is covered by the perineal membrane called the inferior fascia of the urogenital diaphragm<\/li>\n<\/ul>\n
This triangular diaphragm occupies the urogenital triangle with its apex behind the pubic symphysis and its sides are attached to the ischiopubic rami. It contains bulbourethral glands in the male.<\/p>\n
Structures piercing UD:<\/strong><\/p>\n\n- In male:<\/strong> Urethra.<\/li>\n
- In females:<\/strong> Urethra and vagina.<\/li>\n<\/ul>\n
Urogenital Relations:<\/strong><\/p>\n\n- Below: <\/strong>Superficial perineal pouch.<\/li>\n
- Above:<\/strong>\n
\n- The apex of the prostate in males\/neck of the bladder in females.<\/li>\n
- Anterior fibers of levator ani muscles.<\/li>\n
- Anterior recesses of ischiorectal fossa.<\/li>\n<\/ul>\n<\/li>\n
- In front: <\/strong>Triangular gap between the arcuate pubic ligament and transverse perineal ligament. This gap transmits deep dorsal vein of penis\/clitoris.<\/li>\n<\/ul>\n
Urogenital Actions:<\/strong><\/p>\n\n- Supports prostate\/bladder<\/li>\n
- Constricts vagina in the female<\/li>\n
- Fixes perineal body<\/li>\n
- Constricts urethra<\/li>\n<\/ul>\n
Question 6. Write a short note on the superficial perineal pouch.<\/strong>
\nAnswer:<\/strong><\/p>\nThe superficial perineal pouch is a space between Colles\u2019 fascia and the perineal membrane.<\/p>\n
Superficial perineal pouch Boundaries:<\/strong><\/p>\n\n- Inferior\/floor Colles\u2019 fascia.<\/li>\n
- Superior (roof) Perineal membrane.<\/li>\n
- On each side Ischiopubic ramus.<\/li>\n
- Posterior Posteriorly, the space is closed by the fusion of Colles<\/strong>\u00a0fascia and perineal membrane.<\/li>\n
- Anterior Anteriorly, it remains open and is continuous with spaces of the scrotum, penis, and lower anterior abdominal wall.<\/li>\n<\/ul>\n
Superficial perineal pouch Contents: <\/strong>Sows the contents of the superficial pouch in the male and female.<\/p>\nStructures Within the Superficial Perineal Pouch:<\/strong><\/p>\n![\"Perineum](\"https:\/\/anatomystudyguide.com\/wp-content\/uploads\/2023\/08\/Perineum-Superficial-Perineal-Pouch-Male-And-Female-1.png\")
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Superficial perineal pouch Applied anatomy:<\/strong><\/p>\nRupture of the urethra:<\/strong> The rupture of the urethra superficial to the perineal membrane leads to extravasation of urine in a superficial perineal pouch which subsequently accumulates in the scrotum, penis, and anterior abdominal wall deep to Scarpa\u2019s<\/strong> Fascia,<\/strong> and may extend up to the axilla.<\/p>\nPerineum Anatomy<\/strong><\/p>\nQuestion 7. Write a short note on the deep perineal pouch.
\nAnswer:<\/strong><\/p>\nDeep perineal pouch:<\/strong><\/p>\nThe deep perineal pouch is an interfascial space between the superior and inferior fascia of the urogenital diaphragm. It is situated deep in the perineal membrane in the region of the urogenital triangle.<\/p>\n
![\"Perineum](\"https:\/\/anatomystudyguide.com\/wp-content\/uploads\/2023\/08\/Perineum-Boundaries-And-Contents-Of-The-Deep-And-Superficial-Perineal-Pouches-In-Male.png\")
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![\"Perineum](\"https:\/\/anatomystudyguide.com\/wp-content\/uploads\/2023\/08\/Perineum-Boundaries-And-Contents-Of-The-Deep-And-Superficial-Perineal-Pouches-In-Female.png\")
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perineal pouch Boundaries repetition:<\/strong><\/p>\n\n- Below:<\/strong> Perineal membrane\/inferior fascia of the urogenital diaphragm.<\/li>\n
- Above:<\/strong> Superior fascia of the urogenital diaphragm.<\/li>\n
- On each side:<\/strong> Ischiopubic ramus.<\/li>\n
- Posteriorly:<\/strong> Space is closed by the union of the perineal membrane with the superior fascia of the urogenital diaphragm.<\/li>\n
- Anteriorly:<\/strong> Space is closed by the union of the perineal membrane with the superior fascia of the urogenital diaphragm at the transverse perineal ligament.<\/li>\n<\/ul>\n
Deep perineal pouch<\/strong> Contents:<\/strong><\/p>\n\n- In male:<\/strong>\n
\n- Membranous urethra<\/li>\n
- Bulbourethral glands<\/li>\n
- Dorsal nerve of the penis<\/li>\n
- Artery of penis<\/li>\n
- Muscular branches of the perineal nerve<\/li>\n
- Sphincter urethrae muscle<\/li>\n
- Deep transverse perineal muscle<\/li>\n<\/ul>\n<\/li>\n
- In female:<\/strong>\n
\n- Urethra<\/li>\n
- Vagina<\/li>\n
- Dorsal nerve of clitoris<\/li>\n
- Sphincter urethrae muscle<\/li>\n
- Deep transverse perineal muscle<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n
Deep perineal pouch Applied anatomy:<\/strong><\/p>\nThe rupture of the urethra, deep to the perineal membrane, leads to extravasation of urine in the extraperitoneal space of the pelvis, which subsequently accumulates in the anterior abdominal wall.<\/p>\n
Perineum Anatomy<\/strong><\/p>\nQuestion 8. Describe the ischiorectal\/ischioanal fossa in brief.<\/strong>
\nAnswer:<\/strong><\/p>\nIschiorectal Introduction:<\/strong><\/p>\n\n- It is a wedge-shaped space on each side of the anal canal below the pelvic diaphragm. The two fossae communicate with each other behind the anal canal.<\/li>\n
- They are filled with fat, which helps in the dilatation of the rectum and anal canal, during defecation (i.e., the passage of feces).<\/li>\n
- Dimensions: Length, width, and depth = 2″ \u00d7 1″ \u00d7 2″.<\/strong><\/li>\n<\/ul>\n
Ischiorectal Boundaries:<\/strong><\/p>\n\n- Lateral: <\/strong>Fascia covering obturator internus and medal surface of ischial tuberosity.<\/li>\n
- Medial: <\/strong>Fascia covering levator ani in the upper part and external anal sphincter in the lower part.<\/li>\n
- Posterior: <\/strong>Sacrotuberous ligament.<\/li>\n
- Anterior: <\/strong>Posterior border of perineal membrane.<\/li>\n
- Floor (base): <\/strong>Perineal skin.<\/li>\n
- Roof (apex): The meeting<\/strong> point of fascia covering the obturator internus and anal fascia (inferior fascia of the pelvic diaphragm).<\/li>\n<\/ul>\n
![\"Perineum](\"https:\/\/anatomystudyguide.com\/wp-content\/uploads\/2023\/08\/Perineum-Boundaries-Of-the-Ischiorectal-Fossa.png\")
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Ischiorectal Recesses:<\/strong><\/p>\n\n- Anterior recess: <\/strong>It extends above the urogenital diaphragm and reaches up to the posterior surface of a body of the pubis.<\/li>\n
- Posterior recess<\/strong>: It is small and present deep to the sacrotuberous ligament.<\/li>\n
- Horseshoe recess: <\/strong>It connects 2 ischiorectal fossae behind the anal canal.<\/li>\n<\/ul>\n
Perineum Pain<\/strong><\/p>\nIschiorectal Contents:<\/strong><\/p>\n\n- Ischiorectal pad of fat<\/li>\n
- Inferior rectal nerve and vessels<\/li>\n
- Perineal branch of the 4th sacral nerve (S4)<\/li>\n
- Posterior scrotal (or labial) nerves and vessels<\/li>\n
- Perforating cutaneous branches of S2 and S3 nerves<\/li>\n
- Pudendal Canal and its contents<\/li>\n<\/ul>\n
![\"Perineum](\"https:\/\/anatomystudyguide.com\/wp-content\/uploads\/2023\/08\/Perineum-Contents-Of-The-Ischiorectal-Fossa.png\")
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Ischiorectal Applied Anatomy:<\/strong><\/p>\n\n- Loss of fat in the fossa may lead to rectal prolapse, especially in young children.<\/li>\n
- Ischiorectal abscess: Ischiorectal fossa is the common site of infection due to its location and often leads to ischiorectal abscess. This abscess may either burst into the anal canal or on the surface of the perineum or both.<\/li>\n
- In last case track may form connecting the surface of the perineum to the anal canal called a fistula in ano. The unilateral abscess may become bilateral through horseshoe recess.<\/li>\n<\/ul>\n
Question 9. Describe the pudendal canal (Alcock\u2019s canal) in brief.\u00a0<\/strong>
\nAnswer:<\/strong><\/p>\nPudendal Canal:<\/strong><\/p>\n\n- It is a fascial tunnel situated in the lateral wall of the ischiorectal fossa about 2.5 cm above the ischial tuberosity.<\/li>\n
- It extends from the lesser sciatic notch to the deep perineal pouch.<\/li>\n
- It conveys pudendal nerve and internal pudendal vessels from lesser sciatic notch to the deep perineal pouch.<\/li>\n<\/ul>\n
Pudendal Canal Formation:<\/strong><\/p>\nIt is formed either by splitting of the fascia lunata or by splitting of obturator fascia or by separation between lunata and obturator fascia.<\/p>\n
Perineum Pain<\/strong><\/p>\nPudendal Canal Contents:<\/strong><\/p>\n\n- The pudendal nerve divides within the canal into the dorsal nerve of the penis and the perineal nerve.<\/li>\n
- Internal pudendal vessels.<\/li>\n<\/ul>\n
The arrangement of structures within the canal from above downward is as follows:<\/strong><\/p>\n\n- Dorsal nerve of the penis or clitoris<\/li>\n
- Internal pudendal vein<\/li>\n
- Internal pudendal artery<\/li>\n
- Perineal nerve<\/li>\n<\/ul>\n
Question 10. Describe the pudendal nerve in brief. <\/strong>
\nAnswer:<\/strong><\/p>\nPudendal Nerve:<\/strong><\/p>\nThe pudendal nerve provides principal innervation to the perineum.<\/p>\n
Pudendal Nerve Origin, course, and distribution:<\/strong><\/p>\n\n- The pudendal nerve arises from ventral rami of S2, S3, and S4 in the pelvis. It leaves the pelvis through greater sciatic foramen below the piriformis muscle, medial to internal pudendal vessels.<\/li>\n
- It crosses the dorsum of the ischial spine and immediately disappears through the lesser sciatic foramen to enter the pudendal canal (Alcock\u2019s canal).<\/li>\n<\/ul>\n
![\"Perineum](\"https:\/\/anatomystudyguide.com\/wp-content\/uploads\/2023\/08\/Perineum-Course-And-Branches-Of-The-Pudendal-Nerve.png\")
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In the posterior part of the canal, it gives off:<\/strong><\/p>\n\n- Inferior rectal nerve, which crosses the fossa to innervate the external anal sphincter, perianal skin, and anal canal<\/li>\n
- A large perineal nerve, and<\/li>\n
- A small dorsal nerve of the penis (or clitoris).<\/li>\n<\/ul>\n
The perineal nerve bifurcates almost at once into deep and superficial branches:<\/strong><\/p>\n\n- The deeper branch supplies the sphincter urethrae and other muscles of the urogenital triangle, viz. superficial and deep transverse perineal, ischiocavernosus, and bulbospongiosus.<\/li>\n
- Its superficial branch innervates the posterior 2\/3rd of the scrotum (or labium majus) through the posterior scrotal (or labial nerves).<\/li>\n
- The dorsal nerve of the penis (or clitoris) runs in the pudendal canal and in the deep perineal pouch close to the pubic arch, then traverses through a gap below the arcuate pubic ligament to reach the dorsum of the penis.<\/li>\n<\/ul>\n
Perineum Pain<\/strong><\/p>\nPudendal Nerve<\/strong> Branches:<\/strong><\/p>\n\n- Inferior rectal nerve<\/li>\n
- Perineal nerve<\/li>\n
- Dorsal nerve of penis\/clitoris<\/li>\n<\/ul>\n
Pudendal Nerve Applied Anatomy:<\/strong><\/p>\nPudendal nerve block:<\/strong><\/p>\n