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Flashcards in Digestive Glands Deck (22):
1

what does the parenchyma of digestive glands derive from?

epithelium of the gut tube (endoderm)

2

what are the 3 major salivary glands? what do they secrete?

parotid- all serous, submandibular- mostly serous, some mucous, sublingual- mostly mucous, some serous

3

what is the structure of salivary glands?

branched acinar

4

serous demilune

found in salivary glands with mixed sero-mucous

5

what are the classifications of ducts draining salivary glands?

intralobular- within lobules and interlobular- between lobules

6

what are the two types of intralobular ducts and what is their structure?

smaller- intercalated. simply squamous. closer to gland. intercalated ducts drain into striated ducts. striated ducts are larger and have cuboidal or columnar epithelium.

7

why are striated ducts striated?

their basal membranes have extensive folding and mitochondria accumulate there creating the pattern

8

what type of cell is responsible for the movement of gland secretion in parotid, submandibular and sublingual glands?

myoepthelium

9

describe the structure of an interlobular duct

pseudostratified columnar or, in large ducts, stratified columnar

10

how does the duct modify the secretion in salivary glands?

striated ducts reabsorb Na and Cl to create a hypo-osmotic solution. they also contribute IgA and lysozyme

11

describe 3 ways in which the exocrine pancrease differs from the salivary glands

no striated ducts. no mucous secretion (only serous). retrograde extension of the intercalated ducts into the lumen of the acinar gland.

12

what is the purpose of the retrograde extension of the intercalated ducts

they contribute large amounts of alkaline bicarbonate to the secretion. this will neutralize acidic gastric contents in the duodenum

13

what are the 2 general types of secretions of the pancreas? how is each regulated?

enzymes- proenzymes- amylase, lipase, trypsinogen, etc. controlled by cholecystokinin. water and ions (bicarbonate)- controlled by secretin

14

what are centroacinar cells?

the cells that have been extended backwards from the duct into the lumen of the pancreatic glands

15

describe what happens to blood after it travels through the portal triad

portal triads (branches off bile duct, portal vein, and hepatic artery) are located peripherally. branches will flow inward from the periphery, mix together, and pass through sinusoids on their way to a central vein. hepatocytes have their basal membrane adjacent to the sinusoids, thus can exchange materials

16

kupffer cells

resident liver macrophages found in the endothelium of sinusoids

17

ito cells

vitamin a storage and local immunity, found in the per-sinuoidal space of disse (between the sinusoid and basal membrane

18

describe the different sides of a hepatocyte

basal- faces sinusoid. apical- create walls of bile canaliculi. lateral- adjacent with other hepatocytes

19

how does bile get secreted from hepatocytes

exocytosed out the apical membrane into bile canaliculi, which travel out into terminal ductules (canals of Hering) and ultimately into the portal triad

20

describe the inner wall of the gallbladder

mucosa made of simple columnar epithelium, lamina propria, no muscularis mucosa. the wall is itself folded and the columnar epithelium have microvilli to increase surface area for concentrating bile

21

describe the outer layer of the gallbladder

facing the peritoneum- lined by a visceral membrane. facing the liver, lined by a tunica adventitia

22

how does the gallbladder concentrate bile?

it pumps Na and Cl out of the lumen, causing water to follow