The serous glands are a collection of thin, long mucous glands located in the mucous membrane near the esophagus and in the submucosal layer of the rectum. There are up to 33-45 glands per 1 mm2 of tissue. They secrete mucus and serous secretions. The length of individual glands reaches 8-25 cm, the diameter is 0.5-5 mm. There are no serous glands in the area of the vaginal vault.