Brainscape's Knowledge GenomeTM

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


See full index

Gastrointestinal > Function of the Stomach > Flashcards

Function of the Stomach Flashcards

1
Q

Describe the pathway of hormones in the stomach.

A

Hormones are peptides released from the endocrine cells. They are released into the portal circulation and pass through the liver. They then enter the systemic circulation.

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

Describe Paracrine Signalling.

A

Peptides are released by the endocrine cells and act in a local environment, diffusing through short distances.

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

Describe Neurocrine Signalling.

A

Peptides are released by neurones in the GI tract after an action potential.

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

Give an example of a neurocrine signalling molecule and what it does.

A

Gastrin Releasing Petide increases the release of gastrin from G cells.

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

What are the 2 broad categories of Gastrointestinal Hormones?

A
  1. Gastrin family.

2. Secretin family.

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

Which hormones are part of the gastrin family?

A

Gastrin and Cholecystokinin (CCK).

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

Which hormones are part of the secretin family?

A

Secretin and Gastric Inhibitory Polypeptide.

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

Describe the action of gastrin.

A

Increases gastric acid secretion.

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

Describe the location where gastrin is secreted.

A

G cells in the antrum of the stomach.

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

Describe the action of Cholecystokinin (CCK).

A

Increases pancreatic/gallbladder secretions.

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

How is Cholecystokinin stimulated?

A

By fat and proteins. The gallbladder contracts and the pancreas is stimulated.

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

Where is Cholecystokinin secreted?

A

I cells in the duodenum and jejunum.

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

Where is Secretin secreted?

A

S cells in the duodenum.

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

How is Secretin stimulated?

A

H+ and fatty acids stimulate secretin.

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

What does Secretin do?

A

Increase HCO3 from the pancreas/gallbladder and decrease gastric acid secretion.

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

Where is Gastric Inhibitory Polypeptide (GIP) secreted?

A

Duodenum and jejunum.

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

What stimulates GIP?

A

Sugars, amino acids and fatty acids.

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

What does GIP do?

A

Increase insulin and decrease gastric acid secretion.

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

What are the basic functions of the stomach?

A
  1. Receive food- short term storage.
  2. Disrupt food: vigorous contraction of smooth muscle.
  3. Continue/commence digestion (proteins).
  4. Disinfect.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the epithelial change from the lower oesophagus to the stomach?

A

Stratified squamous to columnar. This is for secretion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe rugae.

A

Mucosa/submucosa are thrown into folds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Name some epithelial cells in the gastric pits/glands.

A
  1. Mucous cells.
  2. Parietal Cells.
  3. Chief Cells.
  4. G cells.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Name the layers of the stomach smooth muscle.

A
  1. Circular.
  2. Longitudinal.
  3. Oblique.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What does the extra oblique layer of muscle in the stomach do?

A

Contractions: to mix/grind the contents and move the contents along.

25
Q

Describe the smooth muscle in the upper stomach.

A

The upper stomach has sustained contractions which create a basal tone.

26
Q

Describe the smooth muscle in the lower stomach.

A

Strong peristalsis mixes the stomach contents. This movement is coordinated, with contractions every 20 seconds. The movements are proximal to distal.

27
Q

Describe the shape of the stomach and how this ensures the stomach functions effectively.

A

Larger (proximal) to smaller (distal.
The shape allows the contents to accelerate. The lumps are left behind to separate contents. Liquid chyme is ejected into the duodenum 3 times a minute.

28
Q

What is the arterial blood supply to the stomach?

A

Coeliac trunk.

29
Q

What is the venous drainage of the stomach?

A

Portal Vein.

30
Q

Describe the stomaches function of receiving food.

A

Food is received from the oesophagus. Food is stored because we consume food faster than we can digest.
Food is able to enter because of receptive relaxation (l
vagally mediated relaxation of the orad stomach. This allows food to enter the stomach without raising the intra-gastric pressure too much. This prevents reflux of the stomach contents during swallowing.
The rugae allow for this distension.

31
Q

Describe the digestion is the stomach.

A

Acidic conditions help to:

  1. Unravel proteins.
  2. Activate proteases (pepsinogen to pepsin).
  3. Disinfect the stomach contents.
32
Q

What does the stomach secrete?

A
  1. HCl.
  2. Intrinsic factor.
  3. Mucus/HCO3-.
  4. Pepsinogen (pepsin).
33
Q

What does the parietal cell produce?

A

HCl and intrinsic factor.

34
Q

What do G cells produce?

A

Gastrin.

35
Q

What does the Enterochromaffin Like Cell (ECL) produce?

A

Histamine.

36
Q

Which cells produce Pepsinogen?

A

Chief Cells.

37
Q

What cells produce somatostatin?

A

D Cells.

38
Q

What do mucous cells (surface and neck) produce?

A

Mucus.

39
Q

Where are things secreted from?

A

Gastric Pit and Gastric Gland.

40
Q

Where are parietal cells located?

A

The body of the stomach.

41
Q

Where are chief cells located?

A

The body of the stomach.

42
Q

Where are mucous cells located?

A

The antrum of the stomach.

43
Q

Which cells are located in the cardia?

A

Predominantly mucus secreting cells.

44
Q

What is secreted in the fundus/body?

A

Mucus, HCl and pepsinogen.

45
Q

What is secreted in the pylorus?

A

Gastrin and somatostatin.

46
Q

How is HCl production controlled?

A

Parietal cell are stimulated by:

  1. Gastrin by G cell.
  2. Histamine by Enterochromaffin like cell.
  3. ACh.
47
Q

Describe the control of gastrin secretion.

A

G cells are stimulated by:

  1. Peptides/amino acids in the stomach lumen.
  2. Vagal stimulation by ACh and GRP.
48
Q

How do you inhibit HCl production?

A

Inhibit G cells.

  1. Food leaves stomach.
  2. pH drops as food acts as a buffer.
  3. Low pH activates D cells to make somatostatin.
  4. Somatostatin inhibits G cells.
  5. Stomach distension reduces causing reduced vagal activity.
49
Q

Describe how HCl is produced?

A

Chloride from the blood moves in via the anion antiport protein and HCO3- moves out. The chloride then moves into the apical side by a chloride channel protein. the HCO3- is replenished by carbon dioxide diffusing into the stomach and dissociating into HC03- and H+ via carbonic anhydrase. This means H can move out in the apical membrane by a H+/K+ ATPase. The potassium is moving out so to maintain it a K+ channel protein is present.

50
Q

Name the 3 stages of digestion.

A
  1. Cephalic.
  2. Gastric.
  3. Intestinal.
51
Q

Describe the Cephalic Stage of Digestion.

A

The cephalic stage makes 30% of the total HCl. It is activated by parasympathetic stimuli stimulated by smelling, tasting, chewing and swallowing. There is a direct stimulation of parietal cells by the vagus nerve and stimulation of G cells with GRP released.
Anticipating the food also increases gastric motility.

52
Q

Describe the Gastric Stage of Digestion.

A

The gastric stage makes 60% of the total HCl. Distension of the stomach stimulates the vagus nerve which stimulates the parietal and G cells. The presence of amino acids and small peptides stimulates G cells. The food acts as a buffer in the stomach, removing inhibition of gastrin production.
The enteric nervous system and gastrin cause strong muscle contractions.

53
Q

Describe the Intestinal Stage of Digestion.

A

The intestinal stage of digestion makes 10% of the total HCl production. Chyme initially stimulates gastrin secretion as partially digested proteins are detected in the duodenum (a short phase). This is soon overtaken by inhibition of G cells by the presence of lipids activating the enterogastric reflex, reducing the vagal stimulation. Chyme stimulates CCK and secretin to help suppress secretion.

54
Q

How does the stomach protect itself from digestion?

A
  1. Mucus by surface mucous cells and neck cells.
  2. HCO3- release by surface mucous cells and neck cells.
    This in combination forms a thick alkaline viscous layer that adheres to epithelium keeping it at a high pH.
  3. High turnover of epithelial cells to keep the epithelia in tact.
  4. Prostaglandins: maintain mucosal blood flow, supplying the epithelium with nutrients.
55
Q

Name factors that beach the stomach defences?

A
  1. Alcohol.
  2. Helicobacter pylori.
  3. NSAIDs.
56
Q

Explain how alcohol disrupts the stomach defences?

A

Dissolves the mucus layer.

57
Q

Explain how helicobacter pylori disrupts the stomach defences?

A

Chronic active gastritis.

58
Q

Explain how NSAIDS disrupt the stomach defences?

A

Inhibit prostaglandins which maintain mucosal blood flow to supply the epithelium with nutrients.

Gastrointestinal (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions