Digestive Glands, Liver, and Pancreas Flashcards Preview

Histology Exam III Material > Digestive Glands, Liver, and Pancreas > Flashcards

Flashcards in Digestive Glands, Liver, and Pancreas Deck (22)
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1
Q

Generalizations of the pancreas and CT support

A

-Lobulated, compound, tubulo-alveolar gland with both an exocrine and an endocrine secretory function

CT support:

  • No organized capsule
  • think layer of loose CT from which septa pass internally dividing the gland into many small lobules
  • The delicate CT contains blood vessels, lymphatics, nerves, and excretory ducts
2
Q

What is the main excretory duct of the pancreas

A

Duct of Wirsung

3
Q

What is the smaller accessory duct of the pancreas

A

Duct of Santorini

4
Q

Interlobular ducts of the pancreas are lined with

A

simple columnar epithelium and goblet cells

5
Q

Intercalated ducts of the pancreas are lined with

A
  • low cuboidal cells
  • cells with receptors for secretin
  • Cells secrete water and bicarbonate ion
6
Q

Intercalated ducts of the pancreas structure and secretion

A
  • lined with low cuboidal cells
  • Cells with receptors for secretin
  • Cells secrete water and bicarbonate ion
7
Q

Acinar cells are _______ serous cells

A

pyramidal

8
Q

Histological appearance and function of Acinar cells

A
  • Basal zone which is basophilic and contains nucleus and RER
  • Apical zone with zymogen granules:
    • Precursors of the enzymes in pancreatic juice
    • Trypsin, Chymotrypsin, Amylase, and Lipase
    • Specific receptors for cholecystokinin
9
Q

Histology of Centroacinar cells

A
  • Form a truncated cuboidal epithelium within the lumen of acini
  • Continuous with the epithelium of the intercalated duct
  • Unique to pancreas
10
Q

Acinus structure and function

A
  • Are serous glands
  • No striated ducts
  • No myoepithelial cells
  • contain Acinar, Centroacinar, ductal epithelial cells
    fxn:
    • release of digestive enzymes from serous acinar cells is stimulated by CCK
    • Bicarbonate-rich, alkaline fluid is released by ductal epithelial cells in response to secretin
11
Q

function of CCK on pancreas

A

triggers the release of digestive enzymes from serous acinar cells

12
Q

Function of secretin on pancreas

A

triggers the release of bicarbonate-rich, alkaline fluid from ductal epithelial cells of Acini

13
Q

Digestive enzymes are concentrated and stored in vesicles by _____

A

Golgi apparatus

14
Q

Pancreatic digestive enzymes are referred to as

A

zymogen granules

15
Q

Synthesis and secretion of pancreatic digestive enzymes is controlled by _______ secreted by _________

A

Cholecystokinin (CCK), which is a peptide hormone secreted by duodenal enteroendocrine cells

16
Q

Secretion of bicarbonate ions from the ductal epithelial cells of the Acini in the pancreas is regulated by _____ which is secreted by ____ when stimulated by food entering the _______

A

Secretin, duodenal enteroendocrine cells, small intestine

17
Q

Synthesis pathway of bicarbonate ions

A
  • Carbon dioxide diffuses into intercalated ducts form blood
    • CO2 + H2O —> H2CO3 (requires carbonic anhydrase)
  • H2CO3 —> HCO3- + (H+)
  • HCO3- is actively transported to lumen of intercalated duct
  • Na+ and H+ are changed with Na+ flowing into duct lumen and H+ flowing into blood
18
Q

These are endocrine cell aggregations which are interspersed irregularly among the acini of the pancreas

A

Islets of Langerhans

19
Q

What are the 3 cell types of the Islets of Langerhans

A
  • A-cells (alpha cells)
  • B-Cells (beta cells)
  • D-Cells (delta cells)
20
Q

function of alpha cells in islets of langerhans

A

Produce Glucagon

21
Q

Function of beta cells in islets of langerhans

A

produce insulin

22
Q

function of D cells in islets of langerhans

A

secrete somatostatin, which helps to control levels of insulin and glucagon