Division of Bronchi into Bronchioles

Primary Bronchi

Extrapulmonary in the conducting respiratory zone surrounded by hyaline cartilage with mucus glands present

Secondary Bronchi

Intrapulmonary in the conducting respiratory zone surrounded by hyaline cartilage with mucus glands present

Tertiary Bronchi

Intrapulmonary in the conducting respiratory zone surrounded by hyaline cartilage with mucus glands present

4th order bronchi, 5th order bronchi, etc.

Intrapulmonary in the conducting respiratory zone surrounded by hyaline cartilage (starting to see smooth muscle) with no mucus glands present

Large Bronchioles

Intrapulmonary in the conducting zone surrounded by smooth muscle with no mucus glands present

Small Bronchioles

Intrapulmonary in the conducting zone surrounded by smooth muscle with no mucus glands present

Terminal Bronchioles

Intrapulmonary in the conducting zone surrounded by smooth muscle with no mucus glands present

Respiratory Bronchioles

Intrapulmonary in the respiratory zone surrounded by smooth muscle with no mucus glands present

Alveolar Ducts

Intrapulmonary in the respiratory zone surrounded by alveoli made of simple squamous epithelia with no mucus glands present