The Urethra: Normal Anatomy, Radiology, Disease, and Injury

Abstract

The male urethra is divided anatomically and radiologically into the anterior and posterior urethra. The anterior urethra extends from the inferior fascia of the urogenital diaphragm to the external meatus. The anterior urethra consists of the penile urethra, from the external meatus to the penoscrotal junction below and the suspensory ligament above, and the bulbous urethra, from the penoscrotal junction to the inferior aspect of the urogenital diaphragm. The posterior urethra consists of the membranous urethra within the urogenital diaphragm and is approximately 1–1.5 cm long. It extends from the inferior fascia of the urogenital diaphragm to the inferior aspect of the verumontanum. The prostatic urethra extends from the inferior aspect of the verumontanum to the bladder neck and passes through the prostate gland a little anterior to the middle of the prostate. The urogenital diaphragm, which divides the urethra into the anterior and posterior urethra, is a triangular ligament extending horizontally from the inferior rami of the pubic arch, posteriorly attaching to the tendinous plate of the perineum and continuous with the anal fascia.