MALE PERINEUM LECTURE BY PROF. ANSARI 16-05-07 WEDNESDAY 09.30-10.30 AM

BOUNDARIES OF PERINEUM

Anterior triangle of perineum It is also called as urogenital triangle. In male,it contains male external genitalia, perineal muscles and perineal pouches. In females,female external genitalia,perineal muscles and pouches are the contents.

Female urogenital triangle

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The Colles’ fascia The Colles’ fascia is the extension of superficial fascia from ant. Abdominal wall getting attached to pubic symphysis,pubic tubercles,conjoint ischiopubic rami, and free border of peineal membrane.

The posterior triangle is the anal triangle

The deep perineal pouch is the space between perineal membrane and superior fascia of urogenital diaphragm

The perineal muscles of male Superficial transverse perineii muscle, Deep transverse perineii muscle, Bulbospongiosus, Ischiocavernosus, Sphincter ani externus, Perineal body, Sphincter urethrae, Pelvic diaphragm.

The bulbospongiosus on contraction expels last/final drops of urine & semen. The ischiocacvernosus helps in fixing the root of penis to get attached to the conjoint ischiopubic rami and also helps in erection of penis. The perineal body is a fibromuscular tendon formed by intersection of perineal muscles,helps in supporting the pelvic organs.

Erection,emission & ejaculation The erection of penis is a parasympathetic activity, controlled by S2+3+4 segments. The emission of seminal fluid is due to the peristalsis of ductus deferens+seminal glands+prostatic fluid + and bulbourethral glands. Emission is a sympathetic response, L1+L2 segments.

The ejaculation results from Closure of the internal urethral sphincter at the neck of the urinary bladder- sympathetic response (L1+L2). Contraction of the urethral muscle – parasympathetic response (S2+S3+S4). Contraction of the bulbospongiosus muscles,Pudendal nerves (S2+3+4).

The perineal nerves

The perineal vessels

The nerves of perineum

Applied anatomy Extravasation of urine in to the superficial perineal pouch after injury and rupture of membranous urethra. Pudendal nerve block is done for surgery in the perineum region. Injury to the perineal body leads to prolapse of rectum rectocele/bladder cyctocele/ and prolapse of uterus.

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