Bronchiole

Definition

Bronchioles are small air passages in the lungs that branch off from the bronchi and lead to the alveoli. They play a crucial role in regulating airflow and gas exchange.

5 Must Know Facts For Your Next Test

1. Bronchioles lack cartilage which makes them more susceptible to collapse or obstruction.
2. They are lined with smooth muscle, allowing them to constrict or dilate and thus regulate airflow.
3. Bronchioles are part of the lower respiratory tract, which is often affected by infections such as bronchiolitis.
4. The terminal bronchioles mark the end of the conducting zone of the respiratory system, where no gas exchange occurs.
5. Respiratory bronchioles lead into alveolar ducts and then into alveolar sacs where gas exchange primarily happens.

Review Questions

• What structural feature makes bronchioles more prone to obstruction?
• How do bronchioles contribute to regulating airflow in the lungs?
• What type of infections commonly affect the bronchioles?

Related terms

Bronchus: A larger airway in the respiratory tract that branches into smaller airways called bronchioles.

Alveolus: A tiny air sac within the lungs where gas exchange occurs between air and blood.

Smooth Muscle: Type of involuntary muscle found within various internal structures including bronchioles, allowing them to constrict or dilate.