Internal urethral sphincter

Ok kiddo, so you know that when you go pee-pee, the urine comes out of your body through a tube called the urethra. Well, there is a special little muscle called the internal urethral sphincter that helps keep the urine in your bladder when you don't want to go potty.

When you have to pee, the muscle starts to relax and let the urine flow out. But when you're done going potty, the muscle tightens back up to keep any more pee from coming out until the next time you need to go. This muscle is like a guard that stays at the bottom of your bladder, making sure that your pee only comes out when you want it to. It's a really important part of your body that helps you stay clean and healthy.