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):
1

Generalizations of the pancreas and CT support

-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

What is the main excretory duct of the pancreas

Duct of Wirsung

3

What is the smaller accessory duct of the pancreas

Duct of Santorini

4

Interlobular ducts of the pancreas are lined with

simple columnar epithelium and goblet cells

5

Intercalated ducts of the pancreas are lined with

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

6

Intercalated ducts of the pancreas structure and secretion

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

7

Acinar cells are _______ serous cells

pyramidal

8

Histological appearance and function of Acinar cells

-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

Histology of Centroacinar cells

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

10

Acinus structure and function

- 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

function of CCK on pancreas

triggers the release of digestive enzymes from serous acinar cells

12

Function of secretin on pancreas

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

13

Digestive enzymes are concentrated and stored in vesicles by _____

Golgi apparatus

14

Pancreatic digestive enzymes are referred to as

zymogen granules

15

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

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

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 _______

Secretin, duodenal enteroendocrine cells, small intestine

17

Synthesis pathway of bicarbonate ions

- 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

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

Islets of Langerhans

19

What are the 3 cell types of the Islets of Langerhans

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

20

function of alpha cells in islets of langerhans

Produce Glucagon

21

Function of beta cells in islets of langerhans

produce insulin

22

function of D cells in islets of langerhans

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