Sphincter facts for kids
A sphincter is a special kind of muscle. It's shaped like a ring and can open or close a body part. Think of it like a natural valve.
When a sphincter muscle tightens, it closes off a passage or opening. When it relaxes, it opens up. This allows things like liquids or solids to pass through.
You can find sphincters in many different animals. The human body alone has over 60 types! Some are very tiny, even microscopic.
What Do Sphincters Do?
Sphincters are very important for controlling what moves inside your body. They help manage the flow of liquids and solids.
For example, many marine mammals, like whales, have sphincters in their blowholes. These muscles help them close their blowholes when they dive underwater.
Sphincters and Digestion
Many sphincters work hard every day as part of your digestion system. They help food and waste move through your body correctly.
- Lower Esophageal Sphincter: This sphincter is at the top of your stomach. It acts like a gate, keeping stomach acids and food from going back up into your esophagus (the tube that carries food from your mouth to your stomach).
- Anal Sphincters: At the end of your digestive system, you have two sphincters in your anus. These muscles control when feces (poop) leaves your body. They help you hold it in until you are ready to go to the bathroom.
