Glands are organs of the human body that manufacture some liquid products which are secreted from the cells. There are two types of glands:
(1) Ducted Glands: They secrete their products through well defined ducts
e.g., liver- secretes bile in the stomach ; Lachrymal- tears in the eyes; salivary - saliva in the mouth ; Sweat glands in the skin - secrete
sweat.
(2) Ductless glands: Also called endocrine glands or internally secreting glands. They secrete hormones directly into the blood stream in response to brain's instructions.