Anatomy of the lower urinary tract

The lower urinary tract consists of the bladder and urethra and, in the male, the prostate. The function of the lower tract is the storage of urine produced by the upper tract and the voluntary expulsion of urine at an appropriate time and place. The lower tract may be affected by functional disorders such as bladder overactivity and urinary incontinence or by carcinoma, lithiasis and obstructive disorders such as prostatic enlargement and stricture disease. A thorough knowledge of the relevant anatomy is vital to understand the pathophysiological mechanisms and appropriate management of these conditions. There are considerable variations in the anatomy and biomechanics of the male and female urinary tract and we depict these, in addition to providing a comprehensive description of the histology, vasculature and innervation of the lower urinary tract organs.