Urological Health Prostate Health Anatomy of the Prostate Gland Understanding Prostate Zones and Lobes By Jennifer Whitlock, RN, MSN, FN linkedin Jennifer Whitlock, RN, MSN, FNP-C, is a board-certified family nurse practitioner. She has experience in primary care and hospital medicine. Learn about our editorial process Jennifer Whitlock, RN, MSN, FN Medically reviewed by Medically reviewed by Matthew Wosnitzer, MD on April 28, 2020 twitter linkedin Matthew Wosnitzer, MD, is a board-certified urologic surgeon and physician scientist. He specializes in male infertility. Learn about our Medical Review Board Matthew Wosnitzer, MD on April 28, 2020 Print The prostate is a small gland (about the size of a walnut when it has not been enlarged in size by disease) that wraps around the urethra, the tube that carries urine from the bladder to outside the body. Ariel Skelley / Getty Images While it is small, different areas of the prostate have different functions. Most surgeons attempt to remove only the necessary tissue when performing prostate surgery (for benign enlargement, or outflow obstruction) or a biopsy in order to preserve as much function as possible. For known prostate cancer, surgical intervention includes removal of the entire gland of the prostate (called a radical prostatectomy). When describing the prostate's anatomy, it is divided into both zones and lobes. Your surgeon may refer to a specific zone, a specific lobe, or both when describing your surgery or diagnosis. Zones of the Prostate The prostate anatomy can be divided into zones, which are categorized by the function of the prostate tissue. The prostate is made up of the peripheral, central, and transitional zones. The peripheral zone is the outermost area of the prostate, resting closest to the wall of the rectum. It makes up approximately 70 percent of a healthy prostate gland. The next layer is the central zone, which is approximately 25 percent of the prostate tissue. This area contains the ejaculatory ducts, which help move semen through the urethra and out of the body. The transitional zone of the prostate, resting next to the urethra, makes up around 5 percent of the prostate at puberty. This zone continues to increase in size throughout adulthood. Lobes of the Prostate The anatomy of the prostate is made up of three lobes: the central lobe and lobes on either side called the anterior lobes. The central lobe of the prostate is pyramid-shaped and rests between the ejaculatory ducts and the urethra. The anterior lobes of the prostate rest near the urethra. This tissue is non-glandular, meaning it does not secrete fluids. It is made up of muscle and fibrous tissue. The Size of the Prostate A typical prostate is approximately slightly larger than the size of a walnut and weighs about 10-12 grams. Radiation and some treatments for prostate disease can make the prostate smaller than usual, while diseases such as benign prostatic hyperplasia or prostate cancer can make the prostate much larger than usual, as large as 70-100 grams. It is common for men to experience symptoms, including difficulty urinating, when the prostate begins to enlarge. Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Anatomy of the Prostate Gland. The Ohio State University Hospitals.