内分泌系
the urinary organ
the digestive system
the skeletal system
the arterial system
a secretory organ [gland]
the branch of medicine dealing with the endocrine glands and their secretions
(of exocrine glands) producing a secretion in which part of the secreting cell is released with the secretion
(of exocrine glands) producing a clear aqueous secretion without releasing part of the secreting cell