Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Gastrointestinal > Session 5 - Functions of the stomach > Flashcards

Session 5 - Functions of the stomach Flashcards

1
Q

What are the basic functions of the stomach?

A
  • Receive food (short term storage)
  • Disrupt food (contractions)
  • Continue digestion (mainly proteins)
  • Disinfect
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the basic structure of the stomach?

A

Superior > Inferior

  • Oesophageal entry
  • Cardia
  • Fundus
  • Body
  • Antrum
  • Pylorus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the characteristics of the stomach?

A
  • Simple columnar epithelium
  • Mucosa/submucosa in folds - Rugae
  • Gastric pits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the gastric pits and their functions?

A

Epithelial pits, containing specialised cells.

  • Mucous cells
  • Parietal cells
  • chief cells
  • G cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the muscle layers of the stomach.

A

Inner oblique
Middle circular
Outer longitudinal

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

How does the shape of the stomach affect the chyme?

A

Larger (proximal) to smaller (distal)

Separates the contents - lumps left behind.

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

How is food moved through the stomach?

A

Strong peristalsis.
Proximal to distal. (every 20 seconds)
Liquid chyme ejected into duodenum 3 times per minute.

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

What are the orad and caudad regions of the stomach?

A

Orad - upper stomach

Caudad - Lower stomach

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

How does the stomach expand when food is eaten?

A
  • Vagally mediated relaxation of orad stomach (when food sensed in oesophagus)
  • Rugae can expand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why is it important for the stomach to extend when food is eaten?

A

Prevents an increase in intra-gastric pressure, which prevents reflux of stomach contents during swallowing.

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

Which cells secrete which products in the stomach?

A 
Parietal cell = HCL + intrinsic factor
G Cell = Gastrin
Enterochromaffin like cell = Histamine
Chief cell = Pepsinogen
D Cell = Somatostatin
Mucous cells = Mucus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Which products are mostly secreted in the cardia?

A

Mucus secretions

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

What is mostly secreted by the fundus/body?

A

Mucus, HCL, pepsinogen.

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

Which substances are secreted at the pylorus?

A

Gastrin, somatostatin

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

Which hormones control HCl production?

A 
Parietal cell
Stimulated by:
-Gastrin
-Histamine
-ACh
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Signals from which nerve to the stomach would increase HCl secretion?

A

Parasympathetic - Vagus.

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

What stimulates G-cells at the stomach to secrete gastrin?

A

Presence of peptides/amino acids in stomach lumen.

Vagal stimualtion (ACh, Gastrin-releasing peptide GRP)

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

How is HCl secretion inhibited in the stomach?

A
  1. pH drop when food leaves stomach (food is buffer)
  2. Low pH activates D cells - secrete somatostatin
  3. Somatostatin inhibits G cells. (and enterochromaffin cells) less gastrin, less histamine)
    - thus less H+, less gastrin
  4. Stomach distension reduces, thus reduced vagal activity.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the three phases of digestion?

A
  • Cephalic
  • Gastric
  • Intestinal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is cephalic digestion?

A

a) Parasympathetic stimuli (smelling/ tasting/ chewing/ swallowing) (30% of HCl)
- Causes direct stimulation of parietal cells by vagus.
- Stimulation of G cells by vagus.

b) Anticipating food = increases gastric motility slightly.

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

How does gastric digestion cause digestion of food?

A

60% total HCl
- Distension of stomach - vagal stimulation
=stimulate parietal / G cells

-Presence of amino acids / peptides
=stimulate G cells

-Food acts as buffer
=removes inhibition on gastrin production

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

What role does the enteric nervous system and gastrin have on the stomach?

A

Cause strong smooth muscle contractions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does intestinal digestion cause?

A

10% of HCl production

- Chyme initially stimulates gastrin secretion (partially digested proteins in duodenum)

24
Q

How does chyme in the intestines slow stomach digestion?

A
  • The presence of lipids activate enterogastric reflex, which reduces vagal stimulation to stomach.
  • Chyme stimulate CCK and secretin, helps suppress secretion.
25
Which cells in the stomach protect it from the highly acidic environment?
Mucus and HCO3- secretion by: - Surface mucus cells - Neck cells in gastric glands Forms thick alkaline viscous layer, which adheres to epithelium, keeping it at a higher pH.
26
Which other defenses does the stomach have to protect from the damaging acid effects?
- High turnover of epithelial cells, keeping it intact. | - Prostaglandins - maintain mucosal blood flow and nutrient supply.
27
Which things can breach the stomach's surface epithelial defences?
- Alcohol: dissolves mucus layer - Helicobacter pylori: Chronic active gastritis - NSAIDS: Inhibits prostaglandin
28
What is dyspepsia?
Indigestion! Affects up to 40% adults per year. Impaired digestion in stomach, usually short term.
29
What is gastro-oesophageal reflux disease? What are some symptoms?
``` When stomach contents reflux into oesophagus, causing acid to affect the lower oesophagus (irritate or damage) Symptoms: -Heartburn -Cough -Sore throat (high up reflux) -Dysphagia ```
30
What is barret's oesopagus?
Metaplasia of squamous epithelium of oesophagus to columnar (gastric) epithelium, due to chronic gastro-oesophageal reflux disease.
31
What can treat gastro-oesophageal reflux disease?
Lifestyle: weight, meal time changes, sleeping more upright. Pharmacological: Antacids, H2 agonists, Proton pump inhibitors. Surgery: rare - make a sphincter (from fundus)
32
What can treat gastro-oesophageal reflux disease?
Lifestyle: weight, meal time changes, sleeping more upright. Pharmacological: Antacids, H2 agonists, Proton pump inhibitors. Surgery: rare - make a sphincter (from fundus)
33
What is acute gastritis, and what are its causes?
Acute mucosal inflammation of stomach. - Heavy NSAID use - Lots of alcohol - Chemotherapy - Bile reflux
34
What are symptoms of acute gastritis?
- Asymptomatic OR - Pain, nausea, vomiting (occasional bleeding can be fatal)
35
What is chronic gastritis, and what causes it?
Chronic mucosal inflammation. - H-pylori infection - Autoimmune: e.g. antibodies against parietal cells (Can cause pernicious anaemia)
36
What is pernicious anaemia?
Anaemia caused by lack of intrinsic factor secretion in stomach due to loss of parietal cells. (maybe due to gastritis). This causes reduced vitamin B12 uptake.
37
What are symptoms of chronic gastritis cause by H-pylori?
- asymptomatic or similar to acute. - may have symptoms due to complications: peptic ulcers, adenocarcinoma, MALT lymphoma
38
What are the symptoms of autoimmune chronic gastritis?
- Symptoms of anaemia - Glossitis (inflammation of the tongue) - Anorexia - Neurological symptoms
39
What are the symptoms of autoimmune chronic gastritis?
- Symptoms of anaemia - Glossitis (inflammation of the tongue) - Anorexia - Neurological symptoms
40
What are peptic ulcers?
Defect in gastric/duodenal mucosa. | Must extend through muscularis mucosa.
41
Where are peptic ulcers most common?
First part of the duodenum. | also common in lesser curve of stomach
42
What are the most common causes of peptic ulcer disease?
- Stomach acid - H-pylori - NSAIDS (smoking can cause relapse) (Massive physiological stress e.g. burns)
43
Which symptoms would be found with peptic ulcer disease?
- Epigastric pain: burning/gnawing following meals, or often at night. -Serious symptoms: bleeding/ anaemia early satiety (fullness) Weight loss
44
What is functional dyspepsia?
- Symptoms of ulcer disease | - Peristalsis/ sensation is disturbed, but with no clear physiological reason.
45
Which clinical tests or scans can be performed in diagnosing gastric pathology?
1. Upper GI endoscopy (biopsies) 2. Urease breath test (urea breath test) 3. Erect chest X-ray 4. Blood test (anaemia etc)
46
What is the urease breath test?
Urea breath test. Used to detect if H-pylori present (as it can break down urea to ammonia and CO2) (radio labelled urea taken, then breath tested)
47
How are peptic ulcers treated?
``` - Eradicate H-pylori TRIPLE THERAPY 1) PPI 2) clarithromycin 3) Amoxicillin ``` Stop NSAIDS Endoscopy for bleeding ulcers
48
How do H2 blockers work to reduce peptic ulcers?
Histamine antagonist Block action of histamine at parietal cells. This reduces proton secretion.
49
Which proton pump inhibitor is most commonly given?
Omeprazole
50
Name two H2 blockers used for ulcers.
Cimetidine | Ranitidine
51
How is H-pylori spread? How does it remain in stomach?
Oral to oral, or faecal oral. - Helix, gram -ve - Flagellum = good motility (lives in mucus layer, adhering to epithelium)
52
How does H-pylori cause stomach damage?
- Releases cytotoxins - Expresses endotoxins, like urease, which creates ammonia. Ammonia is toxic to epithelia. - Promotes inflammatory response (self injury)
53
If found only in the antrum, what effect does H-pylori have?
Duodenal ulceration
54
If H-pylori colonisation was in the antrum, and body of the stomach, what would be the symptoms?
Asymptomatic
55
When may H-pylori lead to cancer?
If colonisation is predominantly in the body of the stomach.

Gastrointestinal (9 decks)

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