Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

The Alimentary Canal > Gastric Secretion > Flashcards

Gastric Secretion Flashcards

1
Q

What are the 3 parts of the stomach?

A

Fundus
Body
Antrum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the function of the fundus?

A

Storage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the function of the body of the stomach?

A

Storage
Mucus, HCl, Pepsinogen and intrinsic factor production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of the antrum of the stomach?

A

Mixing/ Grinding
Gastrin production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does mucous neck cells secrete?

A

Mucus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does chief cells secrete?

A

Pepsinogens - inactive precursor of pepsin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does parietal cells secrete?

A

HCl and Intrinsic factor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 3 main gastric glands?

A

Mucous neck cells
Chief cells
Parietal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Explain how HCl is produced and released out apical membrane into stomach lumen

A

CO2 from blood crosses basolateral membrane of cell - joins with water and carbonic anhydrase to make carbonic acid
This dissociates into H and bicarbonate
H uses HKATPase pump
H and Cl join with water to make HCl

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What happens to bicarbonate when dissociated from carbonic acid?

A

Exchanges with Cl across basolateral membrane and leaves into blood to increase pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What can stimulate the HKATPase pump ?

A

Gastrin (hormone) binding on basolateral membrane to release Ca - protein kinase C
Histamine binds to release Gs then AC to convert ATP to cAMP which releases protein kinase A
ACh binds to muscarinic receptor releasing Ca - protein kinase C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What can inhibit the HKATPase pump?

A

Prostaglandins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What 3 mechanisms control gastric acid secretion?

A

Neurocrine - vagus/ local reflexes
Endocrine - gastrin
Paracrine - histamine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Explain the cephalic phase - stimulating gastric acid secretion

A

Sight, smell and taste of food causes vagus nerve to release ACh and G cells to release gastrin - works on parietal cells
Gastrin/ACh works on ECL cells releasing histamine - parietal cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What during the gastric phase stimulates gastric acid secretion?

A

Distention of stomach
Peptides in lumen
Gastrin/ ACh

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does distention of stomach stimulate gastric acid secretion?

A

Triggers vagal/ enteric reflexes releasing ACh which stimulates parietal cells

17
Q

How does peptides in stomach stimulate gastric acid secretion?

A

Triggers G cells which release gastrin - stimulates parietal cells

18
Q

How does gastrin/ ACh stimulate gastric acid secretion?

A

Triggers ECL cells to release histamine which stimulates parietal cells

19
Q

What in the cephalic phase inhibits secretion of gastric acid?

A

Stopping eating decreases vagal activity

20
Q

What in the gastric phase inhibits gastric acid secretion?

A

Decreased pH from increased HCl production then decreases gastrin

21
Q

What in the intestinal phase inhibits gastric acid secretion?

A

Acid in the duodenum
Fat/ CHO in the duodenum

22
Q

How does acid in the duodenum stop gastric acid secretion?

A

Enterogastric reflex and secretin release
These decrease gastric secretion and gastrin stimulation of parietal cells

23
Q

How does fat and CHO in the duodenum stop gastric acid secretion?

A

Causes GIP release which decreases gastrin secretion and parietal HCl secretion

24
Q

What are enterogastrones?

A

Hormones released from gland cells in the duodenal mucosa - secretin, CCK and GIP

25
Q

Why are enterogastrones released?

A

In response to acid , hypertonic solutions, fatty acids or monoglycerides in duodenum

26
Q

What is the function of enterogastrones?

A

Act collectively to prevent further acid build up in the duodenum

27
Q

What are the 2 strategies that enterogastrones use to prevent build up of acid in duodenum?

A

Inhibit gastric acid secretion
Reduce gastric emptying so inhibit motility/ contract pyloric sphincter

28
Q

When is pepsin active?

A

In low pH <3

29
Q

What does zymogen storage prevent?

A

Zymogen is inactive precursor and prevents cellular digestion

30
Q

When is pepsins inactivated?

A

Neutral pH

31
Q

Where is gastric mucus produced?

A

By surface epithelial cells and mucus neck cells

32
Q

Explain the cytoprotective role of gastric mucus

A

Protects mucosal surface from mechanical injury
Neutral pH from bicarbonate protects against gastric acid corrosion and pepsin digestion

33
Q

What is required for vitamin B12 absorption?

A

Intrinsic factor

34
Q

What is the only non-compensated/ essential function of the stomach?

A

Production of intrinsic factor

35
Q

Where is intrinsic factor/B12 complex absorbed?

A

From ileum

36
Q

What is the defect if low production of intrinsic factor?

A

Pernicious anaemia - failure of erythrocyte maturation

The Alimentary Canal (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions