human_reference_atlas Homo sapiens segmental bronchus http://upload.wikimedia.org/wikipedia/commons/d/df/Illu_quiz_lung05.jpg https://ccf-ontology.hubmapconsortium.org/objects/v1.2/VH_F_Lung.glb https://ccf-ontology.hubmapconsortium.org/objects/v1.2/VH_M_Lung.glb https://ccf-ontology.hubmapconsortium.org/objects/v1.4/3d-vh-f-lung.glb https://ccf-ontology.hubmapconsortium.org/objects/v1.4/3d-vh-m-lung.glb UMLS:C0444439 tertiary bronchus VHOG:0001446 EHDAA:7049 EHDAA:7070 tertiary bronchus Wikipedia:Segmental_bronchus uberon NCIT:C33526 UBERON:0002184 MA:0000439 SCTID:245513001 EHDAA:7058 tertiary bronchus EHDAA:7043 EMAPA:37739 EHDAA:7064 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. [WP,unvetted]. FMA:7407 AS bronchus tracheobronchial tree