Cuticle and mucous glands in the oesophagus of an annelid (Nereis virens).
The oesophagus of Nereis virens is divided into anterior and posterior regions and possesses several peculiar features not previously described for cuticle or glands of Polychaetes either in body or foregut integument. The mucous cells which are permanent glands in both regions secrete a carboxylated acidic mucus and possess apical mechanisms permitting the opening and closing of the neck of the glands. The cuticle of the posterior oesophagus bears numerous striated spines and several hypotheses concerning their physiological role are discussed.
D000818:Animals; D004947:Esophagus / Q000648:ultrastructure; D005088:Exocrine Glands / Q000378:metabolism / Q000648:ultrastructure; D009093:Mucus / Q000378:metabolism; D011077:Polychaeta / Q000502:physiology / Q000648:ultrastructure*