Describe serous cells?

Rounded nuclues localized at junctions of middle and lower third of the cell, apical pole has granulation, limits barely the visibility of its lumen, basal pole rich in RAR and mitochondrion, golgi apparatues developed, secretory apparatues occupy the top of the cell, densely, containing active or inactive enzymes (zymogen) merging with apical pole plasma membrane before going out