Tertiary bronchus
1. Trachea 2. Mainstem bronchus 3. Lobar bronchus 4. Segmental bronchus 5. Bronchiole 6. Alveolar duct 7. Alveolus
Latin	bronchi segmentales

The tertiary bronchi (also known as the segmental bronchi) arise from the secondary bronchi. The respiratory epithelium lining their lumen is surrounded by a layer of smooth muscle. This layer is composed of two ribbons of smooth muscle that spiral in opposite directions. The smooth muscle layer is surrounded by irregular plates of hyaline cartilage which help maintain the patency of the airway.

Each of the tertiary bronchi serves a specific bronchopulmonary segment. There are 10 tertiary bronchi in the right lung, and eight in the left.

The tertiary bronchi get smaller and divide into primary bronchioles.

[edit] Additional images

Bronchi, bronchial tree, and lungs

Cross sectional cut of terminal bronchiole

Human respiratory bronchiole.

[edit] References

Gartner, Leslie P. and James L. Hiatt. Color Textbook of Histology, 2nd ed. (2001). ISBN 0-7216-8806-3

[edit] External links

• 1147863100 at GPnotebook
• SUNY Labs 19:17-0100 - "Pleural Cavities and Lungs: The Bronchi and Their Divisions" (1/2)
• SUNY Labs 19:17-0200 - "Pleural Cavities and Lungs: The Bronchi and Their Divisions" (2/2)

v • d • e Anatomy: lower respiratory system (TA A06.3-5, GA 11.1084) Lower RT Trachea Tracheal rings · Annular ligaments of trachea · Carina Lungs Surface right/left · apex/base/root/hilum · cardiac impression/cardiac notch/lingula borders (anterior, posterior, inferior) surfaces (costal, mediastinal, diaphragmatic) fissures (oblique, horizontal) Airway Conducting zone bronchi · main bronchus (right, left) · lobar/secondary bronchi (eparterial bronchus) · segmental/tertiary bronchi (bronchopulmonary segment) · bronchiole · terminal bronchiole Respiratory zone respiratory bronchiole · alveolar duct · alveolus · alveolar-capillary barrier respiratory system navs: anat nose,larynx/lower+thoracic cavity/physio/dev, noncongen/congen/tumors, symptoms+signs/eponymous, proc