FORM & FUNCTION (Glands) Flashcards
Glandular epithelium:
-secretory cells of the exocrine and endocrine glands
-formed by the proliferation of surface epithelial cells into the underlying connective tissue
Exocrine glands:
-mostly multicellular glands with a ductal system
>connected to surface epithelium
-ducts carry secretions into the sites of utilization
-simple and compound glands
Simple (exocrine) glands:
-one or more secretory units connected to a simple duct
-contain acinus or alveolus
Acinus:
-small and narrow
Alveolus:
-large and distended
Compound (exocrine) glands:
-many secretory units connected to a complex ductal system
Endocrine glands:
-multicellular glands that do not have a ductal system
-secretory products are hormones
-secretion is released into the intercellular fluid and then carried by the blood and lymph
Glands can contain:
-just glandular epithelium OR
-parenchyma (does the job) and stroma (helps hold it together)
Parenchyma:
-both glandular epithelium + ductal system (also composed of epithelial cells)
>glandular epithelium: produces the secretory product
>ductal system: transports the secretory product
Stroma:
-made of connective tissue
Large glands divided:
-into lobes and lobules
Lobules:
-contain secretory units (either acinus/alveolus)
Myoepithelial cells:
-cells that exhibit the characters of both muscle and epithelium
-found at the base of the secretory cells/units
-helps to release the secretion into the duct when contracted in response to a stimulus
Unicellular glands examples:
-goblet cells found among epithelial cells lining the gastrointestinal tract and respiratory tract lumen
Multicellular glands:
-intraepithelial
-extraepithelial
-endocrine
-exocrine (simple and compound)
Multicellular exocrine glands: morphologic characteristics:
-simple tubular
-simple coiled tubular
-simple branched tubular
-simple acinar & simple branched acinar
-simple alveolar & & simple branched alveolar
-compound alveolar
-compound tubular acinar/alveolar
Simple alveolar & simple branched alveolar:
-larger/extended
-lumen is larger
Simple cuboidal: Intralobular duct:
-also called striated ducts
-striations due to abundance of mitochondria
>provide energy for active transport (ex. electrolyte balance)
Stratified cuboidal: Intralobular duct:
-larger interlobular ducts might have stratified columnar epithelium
Types of glands based on nature of secretory product:
-serous
-mucous
-mixed or seromucous
Serous:
-thin watery product
-contains zymogen granules (precursors of enzymes)
-stain pink/purple
-ex. parotid gland, exocrine pancreas
Mucous:
-thick and viscous mucin
-contains mucinogen (precursors of mucin)
-stain white/clear
-ex. salivary gland
Mixed or seromucous:
-contains serous, mucous or seromucous secretory units
-serous towards side/base=serous demilune
-ex. parotid gland, sweat glands
