Digestive Glands, Liver, and Pancreas

Question 1

Generalizations of the pancreas and CT support

Answer 1

-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

Question 2

What is the main excretory duct of the pancreas

Answer 2

Duct of Wirsung

Question 3

What is the smaller accessory duct of the pancreas

Answer 3

Duct of Santorini

Question 4

Interlobular ducts of the pancreas are lined with

Answer 4

simple columnar epithelium and goblet cells

Question 5

Intercalated ducts of the pancreas are lined with

Answer 5

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

Question 6

Intercalated ducts of the pancreas structure and secretion

Answer 6

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

Question 7

Acinar cells are _______ serous cells

Answer 7

pyramidal

Question 8

Histological appearance and function of Acinar cells

Answer 8

• 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

Question 9

Histology of Centroacinar cells

Answer 9

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

Question 10

Acinus structure and function

Answer 10

• Are serous glands
• No striated ducts
• No myoepithelial cells
• contain Acinar, Centroacinar, ductal epithelial cells
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  • 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

Question 11

function of CCK on pancreas

Answer 11

triggers the release of digestive enzymes from serous acinar cells

Question 12

Function of secretin on pancreas

Answer 12

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

Question 13

Digestive enzymes are concentrated and stored in vesicles by _____

Answer 13

Golgi apparatus

Question 14

Pancreatic digestive enzymes are referred to as

Answer 14

zymogen granules

Question 15

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

Answer 15

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

Question 16

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 _______

Answer 16

Secretin, duodenal enteroendocrine cells, small intestine

Question 17

Synthesis pathway of bicarbonate ions

Answer 17

• 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

Question 18

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

Answer 18

Islets of Langerhans

Question 19

What are the 3 cell types of the Islets of Langerhans

Answer 19

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

Question 20

function of alpha cells in islets of langerhans

Answer 20

Produce Glucagon

Question 21

Function of beta cells in islets of langerhans

Answer 21

produce insulin

Question 22

function of D cells in islets of langerhans

Answer 22

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