Synonyms: involuntary muscle of bronchus principalis smooth muscle of bronchus principalis bronchus principalis non-striated muscle non-striated muscle of main bronchus primary bronchus smooth muscle tissue bronchus principalis smooth muscle tissue non-striated muscle of bronchus principalis principal bronchus smooth muscle principal bronchus non-striated muscle non-striated muscle of primary bronchus principal bronchus involuntary muscle bronchus principalis smooth muscle involuntary muscle of primary bronchus primary bronchus non-striated muscle smooth muscle tissue of bronchus principalis main bronchus smooth muscle tissue main bronchus non-striated muscle smooth muscle tissue of main bronchus smooth muscle tissue of principal bronchus smooth muscle of main bronchus bronchus principalis involuntary muscle smooth muscle of principal bronchus involuntary muscle of main bronchus non-striated muscle of principal bronchus smooth muscle tissue of primary bronchus smooth muscle of primary bronchus primary bronchus involuntary muscle primary bronchus smooth muscle principal bronchus smooth muscle tissue main bronchus involuntary muscle involuntary muscle of principal bronchus