Bronchioles

Definition

Bronchioles are the small, thin-walled branches of the bronchi that lead to the alveoli in the lungs. They play a crucial role in air passage and gas exchange within the respiratory system.

5 Must Know Facts For Your Next Test

1. Bronchioles are smaller than bronchi and lack cartilage in their walls.
2. They can constrict or dilate to regulate airflow to the alveoli.
3. The lining of bronchioles contains smooth muscle and elastic fibers.
4. Bronchiole inflammation can occur in conditions like asthma and bronchitis.
5. The smallest bronchioles, called terminal bronchioles, lead directly to alveolar ducts.

Review Questions

• What is the primary function of bronchioles in the respiratory system?
• How do bronchioles differ from bronchi in terms of structure?
• What happens to airflow when bronchioles constrict?

Related terms

Alveoli:

Tiny air sacs at the end of bronchioles where gas exchange occurs.

Bronchi:

The larger airway passages that branch off from the trachea into each lung.

Asthma: A chronic condition characterized by inflammation and narrowing of the airways including the bronchioles.