Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Block 1 Week 2 > Gastric Motility and Secretion > Flashcards

Gastric Motility and Secretion Flashcards

(58 cards)

Start Studying
1
Q

Name 5 functions of the stomach.

A
  1. To store food
  2. To minimize ingestion of bacteria
  3. To dissolve and partially digest the macromolecules in food
  4. To regulate the rate at which the contents of the stomach empty into the small intestine.
  5. To secrete intrinsic factor
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What 3 different things does gastric motility allow the stomach to do?

A
  1. Serve as a reservoir for a large volume of food
  2. Fragment the food into smaller particles and mix it with gastric secretions
  3. Empty gastric contents into the duodenum at a controlled rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What comprises the Orad region of the stomach?

A

The top half of the body of the stomach and the Fundus.

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

What comprises the Caudad region of the stomach?

A

The bottom half of the body of the stomach and the Antrum.

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

What are the folds of the mucosa and submucosa in the stomach called?

A

Rugae

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

What is the mechanism called through which the stomach increases its volume to receive food?

A

Receptive relaxation

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

What is the approximate volume of an empty stomach of an adult?

A

50ml.

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

What are the 4 layers of the wall of the GI tract, going from the lumen outwards?

A
  1. Mucosa
  2. Submucosa
  3. Muscularis
  4. Serosa
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Contractions of what create the rugae in the stomach?

A

Muscularis mucosae

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

In which layer of the GI tract wall is the muscularis mucosae found?

A

Mucosa

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

What are the 2 branches of the enteric nervous system?

A
  1. Myenteric plexus

2. Submucosal plexus

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

What does the submucosal plexus of the stomach influence?

A

Secretion

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

What does the myenteric plexus of the stomach influence?

A

Smooth muscle cell activity

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

Which nerve co-ordinates with the stomach’s enteric nerve plexuses to bring about receptive relaxation?

A

Vagus nerve.

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

What do the enteric neurons release which mediates the relaxation of the smooth muscle cells of the muscularis mucosae?

A

Nitric oxide (NO) and Serotonin.

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

What is chyme?

A

Chyme is a thick semifluid mass of partially digested food and digestive secretions.

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

How many layers of smooth muscle does the muscularis of the stomach consist of? What are they?

A

3 layers:

  1. Inner oblique layer.
  2. Middle layer of circular muscle.
  3. Outer layer of longitudinal muscle.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the different patterns of electrical activity which cross the membranes of smooth muscle cells to coordinate contractions of smooth muscle?

A
  1. Slow waves

2. Action potentials

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

What is another name for the basic electrical rhythm of the GI tract?

A

Slow waves

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

What is another name for the slow waves of the GI tract?

A

Basic electrical rhythm.

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

What is the frequency of gastric slow waves?

A

Approximately 3 per minute.

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

Where in the stomach is the rhythm of gastric slow waves generated?

A

The pacemaker zone.

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

What do slow waves do and not do in relation to contractions?

A

Slow waves do not elicit contractions. They co-ordinate contractions by controlling the appearance of action potentials.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How do hormones and neurotransmitters help to fire action potentials in the stomach?

Study These Flashcards
A

They further depolarize the cell, thereby increasing the amplitude of slow waves.

25
What determines the number of action potentials fired at the peak of the slow waves?
The concentration of the hormones and neurotransmitters.
26
What does the number of action potentials occurring at the peak of a slow wave determine in terms of contractions?
The strength of the muscle contraction.
27
What is the pyloric sphincter?
A ring of smooth muscle and connective tissue between the gastric antrum and the duodenum.
28
In what way do the sympathetic nerve fibres affect the pyloric sphincter?
Increase the constriction of the sphincter.
29
In what way do the parasympathetic nerve fibres affect the pyloric sphincter?
1. Inhibitory vagal fibres relax the sphincter. | 2. Excitatory vagal fibres constrict the sphincter.
30
Which 4 hormones affect the pyloric sphincter and in what way?
1. Gastrin 2. Cholecystokinin 3. Gastric inhibitory peptide 4. Secretin They all elicit constriction of the sphincter.
31
Receptors in the duodenum sense what 3 types of materials which decrease the rate of gastric emptying?
1. High in fat digestion products 2. Highly acidic 3. Very hypertonic
32
What are the 4 main components of gastric juice?
1. Enzymes: pepsinogens, gastric lipase 2. Intrinsic factor 3. Hydrochloric acid 4. Mucus
33
What is secreted by the parietal cells of the stomach?
Intrinsic factor and hydrochloric acid.
34
What is secreted by the G cells of the stomach?
Gastrin
35
What is secreted by the chief cells of the stomach?
Pepsinogen
36
Which cells are predominant in the oxyntic gland area of the stomach?
Parietal cells.
37
What are the 3 primary gastric effects of Gastrin?
1. Stimulation of the secretion of acid, pepsinogens, mucus and bicarbonate. 2. Stimulation of gastric motility. 3. Inhibition of gastric emptying.
38
What are the 2 gastric effects of Histamine?
1. Stimulation of acid secretion. | 2. Increased local blood flow, which supports the increase in metabolism associated with acid secretion.
39
In the stomach, from which cells is histamine secreted?
Enterochromaffin-like cells (ECL).
40
In the stomach which cells produce somatostatin?
D cells.
41
What are the 2 gastric effects of somatostatin?
1. Inhibition of gastrin release. | 2. Inhibition of acid secretion.
42
What causes the conversion of pepsinogen to pepsin?
Exposure to low pH in the gastric lumen.
43
Pepsin accelerates the digestion of what?
Proteins.
44
What type of molecular structure is intrinsic factor?
Glycoprotein.
45
What is intrinsic factor essential for the absorption of?
Vitamin B12.
46
How much HCl does the stomach secrete per day?
Approximately 2-3 litres.
47
What is the pH of the gastric lumen?
Between 1 and 2.
48
What is the general shape of a parietal cell?
Pyramid/triangular.
49
What do the extensive invaginations of the luminal membrane of parietal cells form?
Canaliculi.
50
Why do parietal cells require a high content of mitochondria?
Because parietal cells have many proton pumps. Proton pumps are active transporters which use energy derived from the hydrolysis of ATP. Mitochondria synthesize ATP molecules.
51
What are the 4 steps of the mechanism of acid secretion by parietal cells?
1. H+ and HCO3- are produced from CO2 and H2O. 2. H+ is secreted into the lumen by a H+/K+-ATPase pump (proton pump). 3. HCO3- moves out of the cell, across the basolateral membrane via an antiport with Cl-. 4. Cl- diffuses passively into the lumen via a Cl- channel.
52
Which 3 things stimulate gastric acid secretion?
1. Gastrin 2. Acetylcholine 2. Histamine
53
Which 3 things inhibit gastric acid secretion?
1. Somatostatin 2. Prostaglandins E2 and I2. 3. Intestinal hormones.
54
Which neurotransmitter and hormone stimulate the release of histamine from ECL cells in the stomach?
Acetylcholine and Gastrin.
55
What molecule type are prostaglandins?
Lipids
56
What substance are prostaglandins derived from?
Arachidonic acid.
57
The gastric mucosal barrier requires which 2 things?
Mucus and bicarbonate.
58
What is a gastric ulcer?
A lesion in the gastric mucosa.

Block 1 Week 2 (10 decks)

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