Pee is one of the first body fluids a kid learns about. You probably learned about pee (also called urine) when you were little and started using the toilet instead of diapers. Now that you're older, you can understand much more about the amazing yellow stuff called pee. Parts of the Urinary Tract You drink, you pee. But urine is more than just that drink you had a few hours ago. The body produces pee as a way to get rid of waste and extra water that it doesn't need. Before leaving your body, urine travels through the urinary tract. The urinary tract is a pathway that includes the: kidneys: two bean-shaped organs that filter waste from the blood and produce urine ureters: two thin tubes that take pee from the kidney to the bladder bladder: a sac that holds pee until it's time to go to the bathroom urethra: the tube that carries urine from the bladder out of the body when you pee The kidneys are key players in the urinary tract. They do two important jobs — filter waste from the blood and produce pee to get rid of it. If they didn't do this, toxins (bad stuff) would quickly build up in your body and make you sick. That's why you hear about people getting kidney transplants sometimes. You need at least one working kidney to be healthy. You might wonder how your body ends up with waste it needs to get rid of. Body processes such as digestion and metabolism (when the body turns food into energy) produce wastes, or byproducts. The body takes what it needs, but the waste has to go somewhere. Thanks to the kidneys and pee, it has a way to get out. When you're asked to give a urine sample during a doctor's visit, the results reveal how well your two kidneys are working. For example, white blood cells in the urine can be a sign of an infection. Pee also is a way for your body to keep the right amount of water. Did you ever notice that if you drink a lot, you pee more and the pee is pale yellow? That's because your body is getting rid of extra water and your pee has more water in it than usual. What's Pee Made Of? Let's talk more about how the kidneys filter blood. When blood goes through the kidneys, water and some of the other stuff that is in blood (like protein, glucose, and other nutrients) go back into the bloodstream, while the waste and excess stuff is taken out. Urine is what is left behind. But what is it exactly? Urine contains: water urea, a waste product that forms when proteins are broken down urochrome, a pigmented blood product that gives urine its yellowish color salts creatinine, a waste product that forms with the normal breakdown of muscle byproducts of bile from the liver ammonia You've Got to Go! Once pee is produced, it travels from the kidney to the bladder, where it's stored until you need to go to the bathroom. The bladder expands as it fills; when it's full, nerve endings in the bladder wall send a message to the brain that you need to pee. When you're in the bathroom, ready to go, the bladder walls contract and the sphincter (a ringlike muscle that guards the exit from the bladder to the urethra) relaxes. The urine then flows from the bladder and out of the body through the urethra. For boys, the urethra ends at the tip of the penis. For girls, it's in front of the vaginal opening. Urinary Tract Health You might not think much about peeing or your urinary tract, but here's how you can help keep everything flowing as it should: Drink enough fluids. There's no magic amount, but be sure to drink plenty of water, especially when it's warm out or you're exercising and playing. For girls: Wipe from front to back, especially after going poop. Because of where the urethra is for girls, it's easy for bacteria from poop to get in that area. If some of those bacteria end up in the urinary tract, you could get an infection known as a UTI (urinary tract infection). For everyone: Go to the bathroom when you need to go. Holding too long isn't good for your urinary tract — and it can lead to accidents. Uh-oh! Back to Articles Related Articles Activity: Urinary System Do you know your urinary system? Label the parts of this important body system. Read More Getting a Urine Test (Video) If your doctor wants a urine sample, he or she means pee. It's easy to give a sample. Watch how this test is done in this video for kids. Read More Movie: Urinary System Watch this movie about the urinary system, which produces pee. Read More For Boys: Trouble "Down There" Boys might feel embarrassed if they get hurt or have a health problem "down there." Find out more in this article for kids. Read More Bedwetting Lots of kids wet the bed. Find out more in this article for kids. Read More Quiz: Urinary System Take this quiz about the urinary system, the system that produces pee. Read More How the Body Works Main Page The human body is an amazing machine. Learn more about it through movies, quizzes, articles, and more. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.