Summary histology of glands

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SUMMARY OF GLANDULAR TISSUE
GLANDULAR TISSUE

Glandular epithelia are tissues formed by cells specialized to produce secretion.
There are two types of glands in our body. They are exocrine and endocrine glands.
The cells or parenchyma of these glands develop from epithelial tissue. Exocrine
glands secrete their products into ducts and endocrine glands secrete their products into
the circulatory system.

CLASSIFICATION OF GLANDS:

1.Exocrine and Endocrine glands

2.Unicellular and multicellular
Exocrine glands:

All exocrine glands have the same basic organization: the parenchyma made up of
secretory cells, the stroma made up of connective tissue, the duct system to convey the
secretions out of the gland.
Endocrine glands:

These glands do not have ducts, are highly vascularised, and their secretory products
enter blood stream (capillaries) for systemic distribution
CLASSIFICATION OF EXOCRINE GLANDS

Unicellular glands consist of single cells. eg goblet cells found in the epithelia of
small and large intestines and in the respiratory passages

Multicellular glands: characterized by a secretory portion, an end piece where the
epithelial cells secrete a product, and an epithelium-lined ductal portion which brings
the secretion out of the gland.

Based on secretory unit:

1.Tubular glands: secretory units are straight, coiled, or branched e.g. gastric glands

2.Acinar glands: round or oval secretory units, e.g.salivary glands

3.Alveolar glands: secretory units are flask shaped.greatly distended units are called
saccular glands.

Different types of glands are:

SIMPLE GLANDS: The secretory cells discharge into one duct

1.Unicellular exocrine glands: goblet cells in the intestine