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A Handbook of Biology

Unicellular:

Multicellular:

Responsible for secretion

Consists of isolated

glandular cells. E.g.

Goblet cells of the

alimentary canal.

(NEET 2020)

Contains cluster of cells.

E.g. Salivary glands.

Based on mode of pouring of secretions, glands are of 2 types:

Exocrine glands: Here, secretions are released through ducts (tubes).

Exocrine glands secrete mucus, saliva, earwax, oil, milk, digestive enzymes,

etc.

Endocrine glands: Ductless. They produce hormones which are secreted

directly into the fluid bathing the gland.

ÇØMPØÜÑD ËPÏTHËLÏÜM



Made up of more than one layer

(multilayered) of cells.



Limited

role

in

secretion

&

absorption.



They cover dry surface of skin,

moist surface of buccal cavity,

pharynx, inner lining of ducts of salivary glands and pancreatic ducts.



Function: Protect against chemical & mechanical stresses.



Cell junctions: The junctions that provide structural and functional links

between adjacent cells. They are of 3 types.

01

Tight junctions: Help to stop substances from

leaking across a tissue.

Multi-

layered

cells