The prostate is a glandular organ surrounding the urethra at the outlet of the urinary bladder in males. About the size of a walnut, it plays a role in sexual functioning. The organ develops as a result of male hormonal influence, and it may be subject to a number of conditions associated with aging.
Anatomy
The prostate weighs about 20 g in a normal adult male. It lies behind the pubic bone, or pubic symphisis. The urethra runs from the bladder through the prostate to the penis. The ejaculatory ducts also run through the prostate and meet the urethra. The prostate consists of a central zone surrounding the urethra, a transitional zone, a peripheral zone and the region of the anterior fibromuscular stroma. The fibromuscular tissues of the prostate make up a sphincter that controls the flow of urine, and the glandular tissue adds prostate fluid to semen. The blood supply to the prostate is from the internal pudendal, inferior vesical and middle rectal arteries. Nerves from the autonomic or involuntary nervous system supply the prostate. It drains lymphatic fluid to a number of sites as well.
Function
The prostate gland helps control the flow of urine and seminal fluid through the urethra. The glandular tissue also contributes about one-third of the fluid to semen. The alkaline fluid nourishes and protects sperm from the acidic environment of the vagina. The prostate enhances arousal and orgasm and prevents urine from mixing with the semen during ejaculation. In addition the prostate helps expel semen during ejaculation.
PSA
PSA, or prostate specific antigen, is a protein that is made by both normal and abnormal prostate tissue. Levels of the protein are normally found in the blood and may be elevated in certain disease states. Causes of elevated PSA include perineal trauma, prostate cancer, benign prostatic hyperplasia, also called BPH, and prostate inflammation or infection.
BPH
BPH, or benign prostatic hypertrophy, is the growth of nodules in the prostate, particularly in the area surrounding the urethra. The condition becomes increasingly common with aging, leading to difficulty controlling the stream of urine. It is associated with the potent male hormone DHT, or dihydrotestosterone. Diagnosis is usually made from history and physical exam, including a digital rectal exam, and measurement of the PSA levels. Several classes of drugs and surgical options are available for treatment.
Cancer
Prostate cancer is one of the most common cancers in the United States. According to the National Cancer Institute, the incidence is about 157 per 100,000 people. It is usually detected during screening, but symptoms may be similar to BPH. The most common approaches to screening are digital rectal exam and measurement of PSA. Diagnosis is usually established on biopsy. Treatment depends on how advanced the cancer is at the time of diagnosis. Complete removal of the prostate and radiation treatment are common treatment modalities. More advanced cancers are treated with hormone therapy and chemotherapy.
Prostatitis
Prostatitis means inflammation of the prostate. It may be acute or chronic, infectious, or part of a pelvic pain syndrome. Usual signs of a bacterial infection of the prostate include pelvic pain, pain with urination, fevers, chills, muscle aches and cloudy urine, similar to a bladder infection. Diagnosis includes urine studies, and treatment involves antibiotics. Chronic bacterial prostatitis is similar to acute but is long-lasting and requires a longer course of antibiotics. Chronic abacterial prostatitis or pelvic pain syndromes are of unknown cause and may respond to pain medications such as non-steroidal anti-inflammatory drugs, or NSAIDs.
