GLOSSARY

The bronchial tree is the branching system of airways from the trachea to the terminal bronchioles (and, in a wider definition, to the alveoli), so named because it resembles an upside-down tree.

Hierarchy

• Trachea (trunk).
• Main → lobar → segmental bronchi (large branches).
• Small bronchi → bronchioles → terminal bronchioles (small branches).
• Respiratory bronchioles → alveolar ducts → sacs and alveoli (leaves).

Important Features