2)Submucosa LCT with BV, LV and n ● tracheal gland:mxed ● diffuse LT and ln SIg a= secretory component (secreted by epi cell)+ lg a produced by plasma cell)2) Submucosa: LCT, with BV, LV and N tracheal gland: mixed diffuse LT and LN * S Ig A = secretory component (secreted by epi. cell) + Ig A ( produced by plasma cell)