Exocrine Glands

Question 1

formation of exocrine glands

Answer 1

-stay connected to the surface

Question 2

formation of endocrine glands

Answer 2

• disappearance of duct cells

- pinch off from the surface

Question 3

general structure of exocrine glands

Answer 3

• secretory portion can be acinar or tubular, may be branched, produces secretory product
• conducting portion-branched of unbranced, modifies secretory product by absorption, can contribute to secretion
• simple- means duct isn’t branched
• compound means duct is branched
• tubular, acinar, coiled, and combos of them

Question 4

holocrine secretion

Answer 4

• lyse cell to release substance

- sebaceous

Question 5

merocrine secretion

Answer 5

• exocytosis of vesicle with substance inside

- salivary glands

Question 6

apocrine secretion

Answer 6

• bud vesicles off

- mammary glands

Question 7

serous cells

Answer 7

secrete proteins

• RER at base
• perinuclear golgi
• secretory vesicles in the apical portion
• exocytosis
• secretory product stains with H and E

Question 8

mucous cells

Answer 8

secretes mucous

• RER at the base
• perinuclear golgi
• secretory vesicles in the apical portion
• exocytosis
• mucous is not preserved with H and E, can be stained with PAS

Question 9

myoepithelial cells

Answer 9

• located between basal lamina and secretory or duct cells
• triangular or elongated nucleus
• possess long contractile actomyosin rich processes
• contraction helps expel secretory product
• present in sweat, salivary, and mammary glands

Question 10

ion and fluid transport across epithelium

Answer 10

• tight junctions seal off the apical surface from the basal surface
• differential distribution of ion channels and pumps
• mitochondria provide source of energy
• membrane specializations increase surface area

Question 11

goblet cells

Answer 11

-mucin secreting unicellular glands

Question 12

simple glands in the skin

Answer 12

-sebaceous and sweat glands

Question 13

sebaceous glands

Answer 13

• simple acinar glands
• holocrine secretion
• short duct to hair follicle
• sebum: triglyerides, cholesterol, squalene, wax esters
• holocrine secretion- cells proliferate, differentiate, accumulate lipid droplets and rupture
• acne

Question 14

sebaceous glands and acne

Answer 14

• increased sebaceous gland activity at puberty
• hair follicle may become plugged
• skin bacteria break sebum into free fatty acids
• fatty acids cause irritation and inflammation
• inflammation attract neutrophils, further escalating inflammation

Question 15

sweat glands

Answer 15

• simple coiled tubular glands

- both eccrine and aporcrine sweat glands are merocrine glands

Question 16

eccrine sweat glands

Answer 16

• located in the dermins
• thermoregulation and excretory functions
• sweat-water, ammonia, sodium, chloride, urea, uric acid, organic compounds, bactericidal peptides, proteolytic enzymes
• altered seat composition can be a disease indicatory
• secretion controlled by cholinergic fibers of SNS

Question 17

histological organization of eccrine sweat glands

Answer 17

• stratified cuboidal epithelium
• secretory portion has pale cells that secrete fluid, dark cells that secrete proteins, myoepithelial cells contract to expel product
• conducting portion reabsorbs nacl and water

Question 18

ultrastructure of eccrine sweat glands

Answer 18

• pale/clear cells- tight junctions, membrane infoldings, abundant mitochondria, intercellular canaliculi
• dark cells with RER and golgi, secretory granules
• myoepithelial cells have contractile actin/myosin bundles
• ducts have tight junctions, abundant mito, abundant Na /K ATPase

Question 19

histological organization of apocrine sweat glands

Answer 19

• located in the axillary, areolar and perineal regions
• associated with hair shafts
• simple coiled glands
• merocrine secretion
• large lumen
• simple cuboidal/columnar epithelium
• stimulated by adrenergic nerve fibers

Question 20

compound glands

Answer 20

• salivary glands and pancreas
• CT capsule
• septa divide parenchyma into lobules
• CT stroma has cap plexus, nerves, lymphocytes and plasma cells
• parenchyma has secretory acini or tubules, intercalated ducts, inntralobular ducts
• interlobular ducts in the septa

Question 21

salivary glands

Answer 21

• moisture and lubrication in oral cavity
• initiation of digestion of carbs
• immune defense- lysozyme, lactoferrin and sIgA
• secretion of calcium and phosphate to make acquired pellicle

Question 22

salivary glands clinical correlation

Answer 22

• reduced function due to radiotherapy or disease can lead to dental caries, oral mucosa trophy, speech difficulties
• salivary gland tumors- 80% are benign, pleiomorphic adenoma is 65% of benign tumors, accumulation of cartilage like material produced by myoepithelial cells

Question 23

general organization of salivary glands

Answer 23

• acini or tubules, serous, mucous, mixed, myoepithelial cells
• intercalated ducts-lack secretory vesicles
• intralobular ducts-striated in serous glands
• interlobular ducts-stratified epithelium

Question 24

serous acinar cells

Answer 24

• secrete proteins

- basal RER, golgi, apical secretory vesicles

Question 25

mucous acinar cells

Answer 25

- secrete mucous (heavily glycosilated protein) | - apical junctional complexes, myoepithelial cells, small lumen

Question 26

myoepithelial cells in salivary glands

Answer 26

- reside within the basal lamina - smooth muscle-like - triangular or elongated nuclei - long contractile processes - also present in intralobular ducts

Question 27

striated intralobular ducts in salivary glands

Answer 27

- up to 1.5 L of saliva per day - saliva composition- 7xK, 3x HCO3, 1/10 Na, compared to blood plasma - basal striations-cell membrane infoldings that house mitochondria - apical surface-tight junctions

Question 28

transcytosis- mechanism of sIgA secretion

Answer 28

-plasma cells secrete IgA dimer-->IgA binds receptor on an acinar cell-->endocytosis at the base of an acinar cell-->proteolytic processing-->exocytosis of sIgA at the apical surface

Question 29

parotid gland

Answer 29

-all serous, adipocytes

Question 30

submandibular gland

Answer 30

- mostly serous - compound tubuloacinar gland - some mixed and mucous - mixed with serous demilunes - mostly striated intralobular ducts

Question 31

sublingual gland

Answer 31

-mostly mucous

Question 32

exocrine pancreas

Answer 32

- secretes digestive proenzymes- lipases, nucleases,amylases - inactive proenzymes are activated by enterokinase cleavage in the duodenum - bicarbonate neutralizes stomach acid and creates optimum pH for pancreatic enzymes

Question 33

regulation of exocrine pancreas

Answer 33

- acidic chyme stimulates enteroendocrine cells in duodenum - those cells release CCK and secretin - CCK stimulates proenzymes, secretin HCO3

Question 34

exocrine pancreas 2

Answer 34

- compound acinar gland - serous acini- polarized serous cells, abundant RER and golgi, zymogenic granules in the apical half of the cell -lack of myoepithelial cells - intercalated ducts-protrude into acini as centro acinar cells - produce bicarbonate - intralobular ducts- lact striations, secrete bicarbonate rich fluid - interlobular ducts-low columnar epithelium, also secrete bicarbonate