GI 2: Salivary & Gastric Secretions Flashcards Preview

Physiology for Pharmacy > GI 2: Salivary & Gastric Secretions > Flashcards

Flashcards in GI 2: Salivary & Gastric Secretions Deck (38)
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1
Q

what are the 3 pairs of salivary glands?

A
  1. parotid
  2. submandibular
  3. sublingual
2
Q

what are the 4 things saliva contains?

A
  1. mucous
  2. bicarb and phosphate ions
  3. salivary amylase ptyalin
  4. lysozyme
3
Q

what is the function of mucous in the saliva?

A

lubrication

4
Q

what is the function of bicarb and PO4 in the saliva

A

pH neutralization

5
Q

what is the function of salivary amylase ptyalin?

A

10% of carbohydrate digestion

6
Q

what is the function of lysozyme in saliva?

A

anti-bacterial

7
Q

~___L of saliva is secreted daily

A

1

8
Q

salivary secretions are stimulated by ____ signals in response to taste, touch, sight, and smell

A

parasympathetic

9
Q

lingual lyase breaks down ___

A

lipids

10
Q

the pH is ~___ when it reaches the esophagus

A

6.5

11
Q

the ____ layer of the stomach contains gastric pits

A

mucosa

12
Q

function of surface mucous cells

A

secrete mucous to line and protect

13
Q

function of the mucous neck cells

A

secrete HCO3 (act as buffer)

14
Q

what are the 4 different types of cells in the gastric pits?

A
  1. mucous cells
  2. parietal cells
  3. chief cells
  4. endocrine cells
15
Q

what are the 3 types of endocrine cells and the tings they secrete

A
  1. G cells = gastrin
  2. ECL cells = histamine
  3. D cells = somatostatin
16
Q

what is the function of the mucous cells of the gastric pits?

A

secrete alkaline mucous to protect stomach from its low pH

17
Q

what is the function of the parietal cells?

A

secrete HCL and intrinsic factor

18
Q

what is intrinsic factor?

A

protein needed for absorption of B12

19
Q

what is the function of the chief cells?

A

secrete pepsinogen

20
Q

what does the suffix “ogen” mean?

A

secreted in inactive form

21
Q

once activated, what is the function of pepsinogen?

A

breakdown peptides

22
Q

what is responsible for the stomach’s low pH?

A

HCL secreted by parietal cells

23
Q

what are the 5 functions of HCL secretion in the stomach?

A
  1. antibacterial
  2. denatures proteins
  3. transforma pepsinogen to pepsin
  4. inactivates salivary amylase
  5. activates lingual lipase
24
Q

carbonic anhydrase converts ___ and __ into ___

A

CO2 and H20 into H2CO3

25
Q

H+ is ____ (active/passive) transported in the stomach lumen via_____

A

actively; H+/K ATPase

26
Q

HCO3 is ____ (active/passive) transported in the intestinal fluid via ____

A

passive; HCO3/Cl exchanger

27
Q

CL is transported in the stomach lumen via ___

A

uniport channel

28
Q

acid secretion in the stomach requires translocation of ___ from the cytoplasm to the apical membrane of the cell

A

H/atpases

29
Q

translocation of the H/ATPases is activated by what 3 things?

A
  1. gastrin
  2. histamine
  3. ACh (PNS)
30
Q

explain the potentiation of acid secretion involving histamine

A

histamine increases the cell’s sensitivity to gastrin and Ach, so the response is greater than the sum of the 3 individual effects

31
Q

where are H/atpases typically found before their translocation?

A

vessicles

32
Q

what is the role of somatostatin wrt H/ATPase?

A

reduces translocation to membrane

33
Q

give 2 examples of drugs used to decrease gastric acid secretion

A
  1. proton-pump inhibitor (omeprazole)

2. histamine H2 receptor antagonists

34
Q

explain how intrinsic factor helps with absorption of B12

A

intrinsic factor binds to b12 forming an indigestible complex that is then absorbed by the ileum by endocytosis

35
Q

B12 is critical due to its role in ___ synthese

A

red blood cell (DNA synthesis)

36
Q

list 4 posible causes of B12 deficiencies

A
  1. dysfunction of gastric parietal cells (pernicious anemia)
  2. resection (surgical removal) of terminal ileum
  3. catabolism of the vitamin by bacteria in the small intestine
  4. pancreatic insufficiency
37
Q

adequate absorption of B12 from the diet depends on what 5 things?

A
  1. amount of dietary intake
  2. HCL and pepsin in stomach to free B12 from binding to dietary proteins
  3. pancreatic processes to free B12 from binding to R factors
  4. secretion of intrinsic factor by the gastric parietal cells
  5. intact ileum with functional receptors
38
Q

B12 must be bound to ___ to be protected

A

protein