﻿第七章气管、支气管疾病第一节先天性气道畸形一、气管软化气管软化（tracheomalacia）因气管软骨先天发育不良所致，可同时伴有喉软化（laryngomalacia），两者是先天性喉喘鸣的主要原因。
O O O O B-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis O O O B-dis I-dis I-dis I-dis I-dis I-dis I-dis O O B-dis I-dis I-dis I-dis B-dis I-dis I-dis I-dis O B-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis O O B-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis O O O O O O O O B-dis I-dis I-dis O B-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis I-dis O O O O O B-dis I-dis I-dis I-dis I-dis I-dis O O O O O O