An important criterion for classifying exocrine glands concerns the shape of the secretory portion, in green color in the figure.
A and B – if the secretory unit is shaped as a tubule the gland is called tubulous gland.
C – the same name is used even if the gland does not have an excretory duct, meaning that the tubule secretes and conducts the secretion.
D – Simple branched tubular gland (a single duct with a branched tubular secretory unit).
E – Compound tubular gland (tubular secretory portions and branched duct).
F – Coiled tubular gland click on the link to see drawings of a sectioned coiled tubule
G – when the secretory unit is spherical or oval, it is an acinar gland, also called alveolar gland.
H – compound acinar gland – with a branched duct.
I – mixed tubular-acinar gland – some secretory portions are acini and other are tubules.
Later on we will study the classification of some types of glands according to the morphology and function of their cells.
3-5 Glandular epithelia
CLASSIFICATION OF EXOCRINE GLANDS – 2
