EXOCRINE GLANDS:
Unicellular exocrine glands consist of
single cells
specialized for secretion scattered amongst other non-secretory
epithelial cells of a surface membrane.
They have no ducts, of course,
but they secrete their products directly
on the free surface of open body cavities and
thus, are considered exocrine.
The most common unicellular exocrine glands are the
goblet cells (mucus secreting cells)
found in the epithelium of the
trachea and the digestive tube.