The naive uninflamed condition with low mucin synthesis is illustrated with thin arrows of water flowing into the two left buckets, whereas the metaplastic inflamed condition with high mucin synthesis is illustrated with thick arrows flowing into the two right buckets. Buckets representing WT (+/+) mice have large outlets so that little water accumulates in the naive condition and only a moderate amount in the metaplastic condition, whereas buckets representing SNAP23 Het (+/−) mice have small outlets so that some water accumulates even in the naive condition and a large amount in the metaplastic condition. In all scenarios, hydrostatic pressure increases until steady state outflow matches inflow.