Urinary Tract & Anatomy: Urogenital Tract, Prostate & Prostate Enlargement

Anatomy of the Male Urogenital Tract

The male urogenital tract comprises two functionally distinct but anatomically closely linked systems: the urinary tract and the genital tract.

The urinary tract consists of the kidneys, which filter the blood and produce urine, the ureters, which carry urine from the kidneys to the bladder, the bladder as the storage organ, and the urethra, which carries urine out of the body. In men, the urethra passes through the prostate, the pelvic floor and the penile shaft, making it considerably longer than in the female body; it also serves as the transport route for the ejaculate.

The genital tract begins with the testes, the site of sperm production and testosterone synthesis. The epididymides store the immature sperm and allow them to mature further and gain motility. The vas deferens transports mature sperm to the urethra during ejaculation. The seminal vesicles supply the largest share of the ejaculate volume and produce fructose as an energy source for the sperm. The prostate secretes a protein-rich, slightly acidic fluid that supports the fertilising capacity of sperm. The bulbourethral glands (Cowper's glands) produce a pre-ejaculatory fluid that neutralises the urethra and prepares it for the passage of sperm.

The functional coordination of both systems is ensured by the autonomic nervous system: during urination, the bladder sphincter opens while the ejaculatory duct remains closed; during ejaculation, active closure of the bladder neck prevents semen from flowing back into the bladder (retrograde ejaculation). Disruptions to this coordination – for example after prostate surgery or in diabetic neuropathy – can lead to retrograde ejaculation.

Common conditions of the urogenital tract include urinary tract infections, urethral strictures, infections of the testes and epididymis (orchitis, epididymitis), disorders of sperm production, and congenital malformations such as hypospadias. Diagnosis and treatment of urogenital conditions fall within the core field of urology.

The Prostate – Anatomy and Function

The prostate is a chestnut-shaped exocrine gland with a volume of roughly 20 to 25 ml in a young adult. It sits directly below the bladder, surrounds the proximal urethra, and borders the rectum posteriorly – a positional relationship that makes digital rectal examination an important diagnostic tool.

Functionally, the prostate produces a prostate-specific secretion containing enzymes such as PSA (prostate-specific antigen), zinc, and other substances that help liquefy the ejaculate after coagulation and support sperm activation. The prostate is anatomically divided into zones: the transition zone at the centre is the site of origin of benign prostatic hyperplasia; the peripheral zone, which makes up the largest portion, is the most common site of origin of prostate cancer.

Benign Prostatic Hyperplasia (BPH)

Benign prostatic hyperplasia is the most common urological condition of the ageing man. From the fifth decade of life, nearly every second man shows histological signs of BPH; it is clinically relevant – meaning associated with urinary symptoms – in around a third of men over 60. The exact pathogenesis is multifactorial; hormonal changes with an altered androgen-oestrogen balance and age-related proliferative changes in the transition zone play a significant role.

Enlargement of the transition zone compresses the surrounding urethra and increases outlet resistance. Symptomatically, this results in what are known as LUTS (lower urinary tract symptoms): a weakened or interrupted urinary stream, prolonged urination, delayed onset of urination, a sensation of incomplete bladder emptying, frequent urge to urinate during the day and at night (nocturia), and urgency. In advanced cases, urinary retention can occur.

Important: BPH is benign and not a precursor to cancer; it does not directly increase the risk of prostate cancer. Nevertheless, it should be monitored urologically, since elevated PSA values caused by an enlarged prostate can complicate interpretation in the context of cancer screening.

Treatment depends on the severity of symptoms and the individual burden. For mild symptoms, a watchful waiting approach with regular urological check-ups is possible. Medication options include alpha-1 receptor blockers (relax the smooth muscle in the prostate and bladder neck), 5-alpha-reductase inhibitors (reduce prostate volume by lowering DHT levels), or a combination of both. Herbal preparations (saw palmetto, pumpkin seed extract) have some evidence for mild symptoms. If response to medication is insufficient or complications arise, surgical procedures are indicated; transurethral resection of the prostate (TURP) is considered the gold standard, supplemented by minimally invasive procedures such as laser ablation, water vapour therapy, or prostatic artery embolisation.

Other Prostate Conditions

Prostatitis – inflammation of the prostate – encompasses a heterogeneous group of conditions: acute bacterial prostatitis is a serious condition with fever, perineal pain and urinary symptoms that requires antibiotic treatment. Chronic prostatitis/chronic pelvic pain syndrome (CPPS) is the most common form, often without evidence of a bacterial pathogen and with considerable suffering; treatment is complex and includes medical, physiotherapeutic and psychological approaches.

Prostate cancer is the most common cancer in men in Germany. Early stages are asymptomatic and are detected through PSA testing and digital rectal examination as part of screening. Treatment depends on stage, risk group, and individual factors, and ranges from active surveillance to radical prostatectomy and radiotherapy, up to hormonal and systemic therapy for advanced disease. A relevant surgical consequence for sexual function: after radical prostatectomy, erectile dysfunction and – with non-nerve-sparing technique – a functional shortening of the penis can occur, which require specific aftercare and, if necessary, surgical intervention.