5.3 Flashcards
What is a gland?
A gland is a cell or group of cells that has the ability to manufacture and
discharge a secretion.
How do Glands develop embryologically?
Glands form from epithelial infoldings during embryonic development. Some
retain ducts (exocrine), while others lose them (endocrine).
What is the difference between endocrine and exocrine Glands? Can you give examples of each?
Endocrine glands release hormones directly into the bloodstream without ducts, while exocrine glands secrete substances through ducts onto the body surface or into specific organs; examples of endocrine glands include the pituitary gland and thyroid, while exocrine glands include salivary glands and sweat glands
In general, How are multicellular exocrine Glands constructed?
Multicellular Exocrine Glands – Consist of a secretory unit (produces
secretions) and a duct (transports secretions). Surrounded by connective tissue for support, blood supply, and sometimes myoepithelial cells for secretion assistance.
Where are goblet cells found? What type of secretion do they produce?
The goblet cell is a modified columnar epithelial cell found interspersed amongthe columnar cells of the respiratory and digestive tracts and in the conjunctiva of the eye. Goblet cells secrete mucin, a thick, sticky mixture of glycoproteins and proteoglycans. When combined with water, mucin becomes mucus. The mucus functions in two ways: it helps protect the apical surface of the epithelial layer, and it assists with the entrapment of microorganisms and foreign particles.
Can you describe merocrine, apocrine, and holocrine glands? How do they differ from one another?
Merocrine – Secrete via exocytosis without damaging cells (e.g., sweat glands).
Apocrine – Release secretions by shedding the apex of the cell (e.g., mammary
glands).
Holocrine – Entire cell disintegrates to release its contents (e.g., sebaceous
glands).
How are serous and mucous secretions di\erent?
Serous – Watery, enzyme-rich (e.g., digestive enzymes).
Mucous – Thick, viscous, contains glycoproteins (e.g., respiratory tract mucus).
Mixed Glands – Produce both types (e.g., salivary glands)
