Brainscape's Knowledge GenomeTM

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


See full index

Year 2 GI (JK) > Gastric secretion > Flashcards

Gastric secretion Flashcards

1
Q

What is the fundus of the stomach mainly used for?

A

storage

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

List some of the stomach bodies uses

A

storage

Produce mucus, HCL, pepsinogen and intrinsic factor

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

Why is mucus important in the stomach?

A

To protect from acid

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

What is pepsinogen a precursor for and why is it stored in this way?

A

pepsin - to prevent autodigestion

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

Where is gastrin synthesised?

A

the ANTRUM and duodenum

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

What is gastrin?

A

A hormone produced from g cells which initiates gastric acid secretion by acting on cells in the stomach

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

What is the gastric pit?

A

The top part of the gastric gland containing the surface mucousal cells

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

What do the mucousal neck cells produce? What is special about these cells?

A

mucus

can migrate upwards to become surface mucousal cells

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

What are the 3 parts of the gastric gland?

A

mucous neck cells, parietal cells and chief cells

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

What do the parietal cells produce?

A

HCL, intrinsic factor

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

What do the chief cells produce?

A

pepsinogens

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

Why is it very important for the tight junctions between the cells in gastric glands to be very tight?

A

to prevent acid getting in

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

What 3 substances turn on gastric acid secretion?

A

Gastrin, histamine and acetylcholine

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

What substance turns off gastric acid secretion?

A

prostaglandins

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

What cells does gastrin work on?

A

parietal cells

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

What is released to work on the protein kinase in terms of gastrin?

A

calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Explain the similarities and differences between prostaglandin and histamine action on gastric acid secretion

A

Histamine is stimulatory of adenylate cyclase to convert ATP to cAMP whereas prostaglandins inhibits this process to turn on the cyclic kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is acetylcholine production innervated?

A

By parasympathetic nerves to act on muscarinic cholinergic receptors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What messenger is used in terms of acetylcholine and gastric acid secretion?

A

calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the 3 broad mechanisms of gastric acid secretion?

A

neurocrine
endocrine
paracrine

21
Q

When does the cephalic phase of digestion begin? What does this innervate?

A

thought, smell, sight of food and whilst eating

vagus nerve

22
Q

What does the vagus nerve stimulate in the cephalic phase?

A

acetylcholine release
Work on g cells to form gastrin
These both work on parietal cells

23
Q

What other chemical do acetylcholine and gastrin act on in the cephalic phase?

A

ECL cells to release histamine which also works on the parietal cells

24
Q

What is the gastric phase?

A

food has physically entered the stomach

25
Q

What does the distension of the stomach do in the gastric phase?

A

vagal (long) and enteric (short) reflexes releasing acetylcholine to act on parietal cells

26
Q

What stimulates the G cells to release gastrin in the gastric phase?

A

peptides in the lumen

27
Q

What stimulates histamine release in the gastric phase?

A

Same as in the cephalic phase - gastrin and acetylcholine work on ECL cells to promote histamine release

28
Q

What inhibits the cephalic phase of producing acid?

A

stopping eating as this reduces vagal activity

29
Q

Why does the gastric phase cease to produce acid?

A

pH falls as the acid is produced and this works by negative feedback and reduces gastrin secretion

30
Q

What 2 things does acid in the duodenum stimulate?

A

enterogastric reflex

secretin release

31
Q

What does acid sensed in the duodenum ultimately lead to?

A

reduced gastrin secretion and decreased gastrin stimulation of parietal cells

32
Q

What happens when fat is sensed in the duodenum?

A

GIP is released to decrease gastrin secretion and parietal HCL secretion

33
Q

What are enterogastrones?

A

Hormones released from gland cells in the duodenal mucosa

34
Q

What are the 3 enterogastrones?

A

secretin, CCK, GIP

35
Q

What 4 situations are enterogastrones released in response to?

A

acid ALL IN DUODENUM
hypertonic solutions
fatty acids
monoglycerides

36
Q

What do enterogastrones allow?

A

Prevention of acid buildup in the duodenum

37
Q

What 2 ways do enterogastrones prevent acid buil up?

A

reduce gastric motility and gastric acid secretion

38
Q

What is a zymogen?

A

An inactive precursor

39
Q

Why is pepsin stored as an inactive precursor?

A

to prevent autodigestion

40
Q

What cells secrete pepsinogen?

A

chief cells

41
Q

Is the pepsinogen-pepsin loop positive or negative feedback?

A

positive

42
Q

What pH is pepsin inactivated?

A

neutral

43
Q

What cells in the gastric gland secrete mucus?

A

Epithelial surface cells and mucous neck cells

44
Q

In what 2 ways does mucus protect?

A

From injury - lubrication

From acid - bicarbonate present

45
Q

What is the only essential function of the stomach?

A

intrinsic factor

46
Q

What cells produce intrinsic factor?

A

parietal cells

47
Q

Why is intrinsic factor needed?

A

Vitamin B12 absorption - prevent pernicious anaemia

48
Q

Where is the vit B12 - intrinsic factor absorbed?

A

ileum

Year 2 GI (JK) (39 decks)

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