Sentence:  The natural anatomical and physiological defensive features of the upper respiratory tract , such as the turbinates of the nose and the cilia of the <WSD>trachea</WSD> and larger bronchi , are capable of impinging out the larger particles to which we are ordinarily exposed in our daily existence . 
Meaning of the word marked with <WSD> tags:  membranous tube with cartilaginous rings that conveys inhaled air from the larynx to the bronchi