Lecture 3 - Exocrine Glands

Question 1

glands - what are they made up of? where do they ducts empty?

Answer 1

-glands are aggregations of secretory epithelium
- exocrine glands have ducts that empty products into cavity/surface
-cells that comprise ducts are also epithelium but often dont secrete so they look different from the secretory portion

Question 2

how are exocrine glands CLASSIFIED?

Answer 2

-morphology of ducts: simple (if duct is unbranched) and compound (if duct is branched)
(the larger the compound gland, the more elaborate the duct system)

• morphology of secretory portion: tubular or acinar (round cluster of cells). It is possible to have either of these in simple or compound and some compounds will have a mixture of them

-mode of secretion: merocrine, apocrine, holocrine

-type of secretion (only for merocrine): serous, mucous, mixed

Question 3

classify by morphology - Simple glands (how they are named, 5 examples)

Answer 3

-single unbrnahced duct
-gland named for secretory portion
-secretory portion can be single or branched
-types are simple straight tubular, simple coiled tubular, simple acinar, simple branched tubular, simple branched acinar

Question 4

classify by morphology - compound glands

Answer 4

-generally large structures
-branched ducts converging in common duct; usually seen as multiple sections through tubes of variable height epithelium with obvious lumen
-compound glands classified by structure of secretory portion
-compound tubular, compound acinar, compound tubuloacinar

Question 5

classify by MODE of secretion - merocrine secretion; how comon, best for what, what type of glands can produce it

Answer 5

mode means how secretory cells produe and release their product
-vast majority of glands use exocytosis to do this (i.e. merocrine)
-this mode is best for protein and CHO
-merocrine secretions can be prouced by simple and compound glands

Question 6

classify by MODE of secretion - holocrine and apocrine, what type of secretion compared to merocrine

Answer 6

-some glands make lipid rich secretions that cant be secreted by merocrine glands
-so there are some specialized glands that accumulate lipid in secretory cells, then cells die and cell debris is the gland product = holocrine
-some glands have secretory cells that pinch off lipid rich regions of the cytoplasm and release them from the apical surface = apocrine

Question 7

what is an example of merocrine, holocrine, and apocrine gland

Answer 7

merocrine = salivary gland
holocrine = sebaceous gland
apocrine = mammary gland

Question 8

what are myoepithelial cells? features? where are they prominent

Answer 8

-they are specialized cells found in most glands; especially prominent in apocrine glands
-have molecular features and epithelial cells; contractile function and found at base of epithelium inside the basement membrane

Question 9

type of secretions in merocrine glands

Answer 9

-serous = often protein rich and/or watery
-mucous = CHO rich/sticky
-mixed = both serous and mucous, made by different cells in the same glad (only compound glands)

type of secretion will reflet organelle abundance and staining properties of secretory cells

Question 10

goblet cells - what do they secrete, what are they a special case of, where can they be found

Answer 10

• single cell gland that secretes mucous
  -can be the secretory cell of other types of glands
  -can also be found in isolation
  -they are a special case of a simple gland

Question 11

what is the parenchyma

Answer 11

functional unit of compound glands (ducts and secretory units)

Question 12

what is the stroma

Answer 12

supportive CT - capsulemade up of collagen, elastic and reticular fibers