Functions of the stomach

Question 1

What are the 4 basic functions of the stomach?

Answer 1

Receive food
Disrupt food
Continue digestion
Disinfect

Question 2

Where does the stomach receive food from?

Answer 2

From the oesophagus

Question 3

Why does the stomach have to store food?

Answer 3

As we consume faster than we can digest

Question 4

What is receptive relaxation?

Answer 4

Vagally mediated relaxation of orad stomach which allows food to enter the stomach without raising the intra-gastric pressure too much

Question 5

What does receptive relaxation prevent?

Answer 5

Acid reflux during swallowing and rugae allow distension

Question 6

How does the stomach disrupt food?

Answer 6

Vigorous contractors of the smooth muscle

Question 7

What kind of cells are present in the stomach?

Answer 7

Columnar epithelial cells

Question 8

What are mucosa and submucosal folds called?

Answer 8

Rugae

Question 9

What are the little holes in the stomach called?

Answer 9

Gatric pits

Question 10

What are the names of the different kinds of cells in the stomach?

Answer 10

Mucous cells
Parietal cells
chief cells
G cells

Question 11

What does the extra oblique layer in the stomach do?

Answer 11

Contracts to mix and move contents

Question 12

What does the upper stomach create?

Answer 12

Has sustained contractions which creates a basal tone

Question 13

How does the lower stomach move?

Answer 13

Peristalsis- coordinated movement by contracting every seconds from proximal to distal

Question 14

Where is the stomach larger and smaller and why?

Answer 14

Stomach is large in the proximal and small at distal so contents can be accelerated as like a funnel

Question 15

How often is liquid chyme ejected into the duodenum?

Answer 15

3 times a minute

Question 16

What do acidic conditions help to do?

Answer 16

Unravel proteins
Activate proteases like pepsin
Disinfect stomach

Question 17

What is secreted by the stomach?

Answer 17

HCl
Intrinsic factor
Mucus 
Pensinogen
Histamine 
Gastrin 
Somatostatin

Question 18

What do parietal cells secrete?

Answer 18

HCl and intrinisic factor

Question 19

What is fundus and body?

Answer 19

Parts of the stomach- fundus is near the top and body is near the middle

Question 20

What controls the secretion of HCl?

Answer 20

Gastrin
Histamine
ACh

Question 21

How is HCl inhibited?

Answer 21

Essentially G cells are inhibited which means when food leaves pH will drop, low pH will activate D cells to release somatostatin which inhibits G cells so stomach distention reduces and vagal activity of the stomach

Question 22

What do mucous cells secrete?

Answer 22

Mucus

Question 23

What do chief cells secrete?

Answer 23

pensinogen

Question 24

What do G cells secrete?

Answer 24

Gastrin

Question 25

What do D cells secrete?

Answer 25

Somatostatin

Question 26

What is gastrin released controlled by?

Answer 26

Controlled by peptised and amino acids in stomach lumen and vagal stimulation- ach and gastrin releasing peptide

Question 27

What are the three stages of digestion?

Answer 27

Cephalic Gastric Intestinal

Question 28

What starts of the cephalic phase of digestion?

Answer 28

Parasympathetic stimuli- smelling, tasting, chewing and swallowing

Question 29

What occurs in the cephalic stage?

Answer 29

30% of HCl produced Direct stimulation of parietal cells by vagus nerve Stimulate G cells by vagus nerve and releases GRP Anticipating food increase gastric motility slightly

Question 30

What happens in the gastric phase of digestion?

Answer 30

60% of HCl produced Distention of stomach stimulates Vagus which stimulates parietal and G cells Presence of amino acids and small peptides stimulates G cells Food acts as a buffer in the stomach and removes inhibition of gastrin production Enteric nervous system and gastrin cause strong smooth muscle contractions

Question 31

What happens in the intestinal phase of digestion?

Answer 31

10% of HCl produced Chyme stimulates gastrin secretion Partially digested proteins are detected in the duodenum Quickly overtaken by inhibition of G cells Presence of lipids activates enterogastric reflex Reduces vagal stimulation Chyme stimulates CKK and secretin

Question 32

What are the stomachs defences?

Answer 32

Mucus | HCO3-

Question 33

Why does the stomach need defences?

Answer 33

Designed to digest biological material so can digest itself

Question 34

Where is mucus and HCO3- secreted from?

Answer 34

Mucus cells and neck cells in gastric glands

Question 35

What does HCO3- and mucus form?

Answer 35

A thick alkaline viscous layer that adheres to the epithelium

Question 36

What maintains the epithelium?

Answer 36

Prostaglandins maintain mucosal blood flow and supply epithelium with nutrients

Question 37

What breach stomach defences?

Answer 37

Alcohol can dissolve the mucus layer Heliobacter pyloric is chronic active gastritis NSAIDs inhibit prostaglandins

Question 38

Why is there a part of the stomach called the cardia?

Answer 38

as it is near the heart

Question 39

What is pepsinogen activated in?

Answer 39

The presence of acid

Question 40

What is secreted in the cardia?

Answer 40

Mucus

Question 41

What is secreted from the funds and body?

Answer 41

mucus, HCl and Pepsinogen (acids)

Question 42

What is secreted in the pylorus?

Answer 42

Gastrin and somatostatin (hormones)

Question 43

How is HCl producted?

Answer 43

Gastrin binds to CCK receptor on parietal cell Histamine can bind to H2 receptor Vagus nerve can release ACH

Question 44

How is gastrin produced?

Answer 44

Somatostatin can stimulate | Vagus nerve can stimulate

Question 45

What Cant take aspirin if stomach problems?

Answer 45

damages prostaglandins so ruin blood flow