Exocrine glands





Exocrine glands refer to glands that secrete substances onto an epithelial surface by way of a duct.



Exocrine glands include: sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate and mucous. 



The second type of gland is the endocrine gland which secrete their products directly into the bloodstream. 



The liver and pancreas are both exocrine and endocrine glands.



These organs are exocrine glands because they secrete their products bile and pancreatic juice into the gastrointestinal tract through a series of ducts.



They are endocrine glands because they secrete other substances directly into the bloodstream.



Exocrine glands have both a glandular portion and a duct portion.



The duct portion may be branched.


or unbranched.



The glandular exocrine portion may be tubular or acinar, or may be a mixture  of the two, tubuloacinar.



Exocrine glands are apocrine glands, holocrine glands, or merocrine glands based on secretion.



Merocrine secretion of their substances by exocytosis; pancreatic acinar cells.



Apocrine secretion; a portion of the cell membrane that contains the excretion buds off.



Holocrine secretion occurs when the entire cell disintegrates to excrete its substance; sebaceous glands of the skin and nose.



Serous cells secrete proteins, often enzymes: gastric chief cells and Paneth cells.



Mucous cells secrete mucus:Brunner’s glands, esophageal glands, and pyloric glands.



Mixed glands secrete both protein and mucus: salivary glands.



The  parotid gland is 20% serous.



Sublingual gland is a 5% mainly mucous gland, and the submandibular gland 70%is a mixed, mainly serous gland.



Sebaceous glands secrete sebum, a lipid product. 







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