Perineal membrane

The borders of the anterior compartment are the pubic symphysis ventrally the components of the levator ani muscle laterally (Fig. 1.1b) and the perineal membrane (see Table 1.1) caudally. There is no distinct border between the anterior and middle compartment in the female. The contents of the anterior compartment are bladder and urethra (Fig. 1.1b). 

An additional fibrous structure can be found to close the hiatus ventrally a plate of dense connective tissue fills the space between pubic bone and urethral sphincter, thus constituting the perineal membrane (Fig. 1.11a). 

Fig. l.lla,b. External urethral sphincter (asterisks), a Axial section (400 pm) of a 24-week-old female fetus, embedded in the transverse perineal membrane. x9. b Computer-assisted three-dimensional reconstruction of a female fetus, p o, pubic bone u, urethra... 

This muscle lies deep to the perineal membrane, forming a complete cuff of the urethra, just distal to the prostate. Peripheral fibers anchor to the perineal membrane, the inferior pubic rami and the perineal body. 

From the ischial tuberosity following the posterior border of the perineal membrane. 

Webster GD (1989) Perineal repair of membranous urethral stricture. Urol Clin North Am 16 303-312... 

The membranous urethra, about 1-2 cm long, passes through the uro-genital diaphragm, which contains the Cowper glands. In this tract the urethra is surrounded by the striate sphincter and the perineal muscles. 

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