Replica casts of the entire respiratory airways of experimental animals.

A method is presented for producing silicone rubber replica casts of the entire respiratory airways (nasal cavity, pharyngeal region, and lungs) for toxicological assessment of inhaled particles and gases. Established methods for producing casts of the lungs are combined with other methods for faithful casting of the nasopharyngeal region to simultaneously cast all the respiratory regions of a given animal. The resulting detailed, flexible casts can be examined for comparison of the features and relative positions of the regions of the respiratory tracts of various animal species.