Bronchiole facts for kids

Quick facts for kids Bronchiole
Diagram of the alveoli with both cross-section and external view.
System	Respiratory system

The bronchioles are very small tubes inside your lungs. They are an important part of your respiratory system, which helps you breathe. Think of them as the tiny, final branches of the airways that lead air deep into your lungs. Unlike the larger bronchi, bronchioles do not have cartilage to keep them open. Instead, their walls are made of smooth muscle.

What Are Bronchioles?

Bronchioles are the smallest airways in your lungs. They branch off from larger tubes called bronchi. These tiny tubes get smaller and smaller, like the branches of a tree. They finally lead to tiny air sacs called alveoli. This is where your body takes in oxygen and gets rid of carbon dioxide.

How Bronchioles Work

When you breathe in, air travels down your windpipe (trachea). From there, it goes into your two main bronchi, one for each lung. These bronchi then split into many smaller tubes, and eventually into the even smaller bronchioles.

The bronchioles act like tiny highways for air. They carry the air you breathe all the way to the alveoli. The walls of the bronchioles have special muscles. These muscles can relax to make the tubes wider, letting more air in. They can also tighten to make the tubes narrower. This helps control how much air reaches the alveoli.

Structure of Bronchioles

Bronchioles are different from the larger bronchi because they do not have cartilage rings. Cartilage is a tough, flexible tissue that helps keep the larger airways open. Without cartilage, the bronchioles rely on their smooth muscle walls to stay open.

There are different types of bronchioles:

• Terminal bronchioles: These are the smallest branches that still carry air.
• Respiratory bronchioles: These are even smaller and have some alveoli attached to their walls. This means they can start exchanging gases even before the air reaches the main alveoli.
• Alveolar ducts: These are the final tiny tubes that lead directly into the clusters of alveoli.

All these tiny tubes work together to make sure that the air you breathe reaches the millions of tiny air sacs in your lungs.

Why Bronchioles Are Important

Bronchioles are super important for breathing. They make sure that fresh, oxygen-rich air gets to every part of your lungs. They also help remove carbon dioxide, a waste gas, from your body when you breathe out.

If bronchioles get inflamed or narrow, it can make breathing difficult. Conditions like asthma affect the bronchioles, causing them to tighten. This makes it harder for air to move in and out of the lungs. Keeping your lungs healthy helps your bronchioles work their best!

Images for kids

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  A lobule of the lung enclosed in septa and supplied by a terminal bronchiole that branches into the respiratory bronchioles. Each respiratory bronchiole supplies the alveoli held in each acinus accompanied by a pulmonary artery branch.

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  Lungs showing bronchi and bronchioles.

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  Cross sectional cut of a primary bronchiole.

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  1. Trachea
  2. Primary bronchus
  3. Lobar bronchus
  4. Segmental bronchus
  5. Bronchiole
  6. Alveolar duct
  7. Alveolus

See also

In Spanish: Bronquiolo para niños