Anatomy of the Urinary Tract

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Here’s the ultimate guide to the function of the 4 major parts of the urinary tract.

Understanding how the major parts of the urinary tract work together can be helpful in navigating urinary health related issues. Let’s dive into the urinary system and understand the function of each organ.

• The urinary tract is the body’s system for removing and draining urine to prevent waste and toxins from building up in the blood ⁽¹⁾.
• Urine is made of waste and extra fluids.
• Normal urination occurs when all the parts of the urinary tract are functioning ⁽²⁾
• The urinary tract is made up of the bladder, kidneys, ureters, the urethra, and various muscles that support their functions.

Kidney

• There are two kidneys. One of the main functions of the kidneys is to filter blood. Blood enters the kidneys and filters waste into urine. The urine is then passed to the ureters.
• The kidneys are a powerhouse. Some other functions of the kidneys include filtering blood to be sent back to the heart and producing hormones that produce red blood cells, control blood pressure and maintain bone health ^{(3, 4)}.
• Some common conditions that impact the kidneys include kidney disease, kidney stones, and UTIs.

Ureters

• The ureters are small tubes that are connected to each of the kidneys and the bladder. Their main function is to carry urine from the kidneys to the bladder which is made possible by the muscles of the ureter walls that continually tighten and relax, forcing urine downward, away from the kidneys.
• A few complications in the ureters include ureteral blockages, various congenital diseases, and UTIs.

Bladder

• The bladder is a balloon-like structure where urine is stored ⁽⁵⁾. The walls of the bladder are able to relax and expand which creates a contraction that empties urine through the urethra ⁽³⁾.
• There are nerves in the bladder that alert the brain when it’s time to urinate ⁽³⁾.
• The bladder’s functionality can be impacted by enlarged prostate (for males). A few other complications in the bladder include bladder control conditions, cystitis, and UTIs.

Urethra

• The urethra is the tube that empties urine from the bladder.
• The nerve signals from the bladder tell the brain to squeeze the bladder muscles which squeezes the urine out of the bladder through the urethra ⁽³⁾.
• The urethra can experience inflammation and infections that impact its funcationality making it painful or difficult to urinate.

Since the the urinary tract works together, it can be impacted by various conditions including but not limited to: UTIs, bacterial vaginosis, cystitis, kidney stones, bladder control conditions, enlarged prostate, and more.

UTIs are the second most common infection in the U.S. ⁽⁶⁾. At its most basic level, a urinary tract infection (UTI) occurs when bacteria enters through the urethra and travels up to the bladder ⁽⁷⁾. In the bladder, bacteria multiply and cause an inflammatory response in the body, resulting in the all-too-familiar UTI symptoms. If you’re dealing with the cycle of UTIs, it’s important to seek care from a specialist who understands these infections.

1. Healthdirect Australia. (n.d.). Urinary system. Healthdirect. Retrieved from https://www.healthdirect.gov.au/urinary-system
2. U.S. Department of Health and Human Services. (n.d.). The Urinary Tract & How It Works. National Institute of Diabetes and Digestive and Kidney Diseases. Retrieved from https://www.niddk.nih.gov/health-information/urologic-diseases/urinary-tract-how-it-works 
3. Anatomy of the urinary system. Anatomy of the Urinary System | Johns Hopkins Medicine. (2019, November 19). Retrieved from https://www.hopkinsmedicine.org/health/wellness-and-prevention/anatomy-of-the-urinary-system
4. U.S. Department of Health and Human Services. (n.d.). Your kidneys & how they work. National Institute of Diabetes and Digestive and Kidney Diseases. Retrieved from https://www.niddk.nih.gov/health-information/kidney-disease/kidneys-how-they-work 
5. U.S. Department of Health and Human Services. (n.d.). 15 tips to keep your bladder healthy. National Institute on Aging. Retrieved from https://www.nia.nih.gov/health/15-tips-keep-your-bladder-healthy
6. Medina, M., & Castillo-Pino, E. (2019, May 2). An introduction to the epidemiology and burden of urinary tract infections. Therapeutic advances in urology. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6502976/
7. Mayo Foundation for Medical Education and Research. (2022, September 14). Urinary tract infection (UTI). Mayo Clinic. Retrieved from https://www.mayoclinic.org/diseases-conditions/urinary-tract-infection/symptoms-causes/syc-20353447