① acinus: a serous acinus structure pyramidal or cuboidal ③入 round basally-located N apical zymogen granule-acidophilic basal: basophilic-RER, ribosome function: secret salivary amylase(淀粉酶)① acinus: a. serous acinus: structure: • pyramidal or cuboidal • round basally-located N • apical: zymogen granule-acidophilic • basal: basophilic-RER, ribosome function: secret salivary amylase（淀粉酶）