Upper GI Disorder: Gastric system

Question 1

What are examples of some GI tract disorders?

Answer 1

Gastroesophageal Reflux Disease (GORD)
Peptic Ulder Disease (PUD)
Duodenal Ulcer
Nausea
Emesis
IBS
Diarrhoea
Constipation

Question 2

What are the main sites for therapeutic intervention in GI system?

Answer 2

Stomach
Oesophagus
Mouth 
Pancreas
Liver 
Large intestine
Small intestine

Question 3

What are the accessory organs within the mouth?

Answer 3

Salivary Glands
Teeth
Oral cavity

Question 4

What is the function of the mouth?

Answer 4

Ingestion and fragmentation of food

Question 5

What is oral ulceration?

Answer 5

Break in oral epithelium, which exposes the nerve endings

Question 6

What can cause oral ulceration?

Answer 6

Chemical/physical injury
Infections
Drugs
Malignancy
Systemic disease

Question 7

What is Stomatitis?

Answer 7

Inflammation of the lining of any soft tissues in the mouth

Question 8

What can cause Stomatisis?

Answer 8

Poor oral hygiene
Poorly fitted dentures
Heart burns
Drugs
Allergy 
Infection

Question 9

What is Leukoplakia?

Answer 9

Painless white patches on the side of the mouth

Question 10

What is Dysphagia?

Answer 10

Difficulty swallowing

Question 11

What is the function of the Oesophagus?

Answer 11

Contracts rhythmically to propel food towards stomach

Question 12

What is the function of the Upper Oesophageal Sphincter (UOS)?

Answer 12

It prevents air entering the oesophgus and oesophgopharyngeal reflux

Question 13

What is the function of the Lower Oesophageal Sphincter (LOS)?

Answer 13

Prevents gastroesophageal reflux. The high intraluminal pressure keeps it closed until food needs to be dumped.

Question 14

What are some dysfunctional physiologies and diseases of oesophagus?

Answer 14

GORD- Obesity, Medication, Spicy, acidic, Smoking
Hiatal hernia
Motility disorders

Question 15

What are some examples motility disorders?

Answer 15

Achalasia
Diffuse oesophageal Spasm
Hypercontraction
Ineffective oesophageal Motility

Question 16

What is Achalasia?

Answer 16

Inadequate LOS relaxation

Question 17

What is Diffuse oesophageal Spasm?

Answer 17

Uncoordinated contraction

Question 18

What is Dyspepsia?

Answer 18

Upper GI tract

Includes heartburn, abdominal discomfort, eructation, nausea

Question 19

What is Peptic ulceration?

Answer 19

Benign lesion of gastric/duodenal mucosa at a site where mucosa is exposed to acif and pepsin

Question 20

What are symptoms of dyspepsia?

Answer 20

Epigastric pain

Commonly vommitting

Question 21

How is GORD caused?

Answer 21

Exposure of ‘unprotected’’ oesophageal epithelium to acid

Transient LOS relaxation in absence of swallowing

Question 22

What are the three distinct types of GORD?

Answer 22

Non-erosive reflux disease
Erosive oesophagitis
Barrett’s oesophagus

Question 23

What is Non-erosive reflux disease?

Answer 23

Heartburn

Question 24

What is Erosive oesophagitis?

Answer 24

Acute inflammatory response

Question 25

What is Barrett's oesophagus?

Answer 25

Metaplasis of mucosa

Question 26

Which one of the three types of GORD, poses a risk of cancer?

Answer 26

Barrett's oesophagus

Question 27

What are the acid secreting cells in the oxyntic gland area?

Answer 27

Mucous cells Chief cells Parietal cells ECL cells

Question 28

What are the secreting cells in the pyloric gland area?

Answer 28

Mucous cells G cells D cells No parietal cells

Question 29

Why are there no parietal cells in the pyloric gland area?

Answer 29

Not necessary to secret HCL at the bottom of the stomach

Question 30

Function of the mucous cells

Answer 30

Secrete mucous

Question 31

Function of chief cells

Answer 31

Secrete pepsinogen

Question 32

Function of ECL cells

Answer 32

Secrete histamine

Question 33

Function of parietal cells

Answer 33

Secrete HCl

Question 34

Function of D cells

Answer 34

Secrete somatostatin

Question 35

Function of G cells

Answer 35

Secrete gastrin

Question 36

How many litres of HCl is secreted per day by parietal cells?

Answer 36

1-2 L

Question 37

What concentration is the HCl?

Answer 37

150-160 mM

Question 38

What are the three positive factors in HCl acid production?

Answer 38

Gastrin ACh Histamine

Question 39

What is the one negative regulator in HCl production?

Answer 39

D cells

Question 40

What receptor does ACh bind to in the acid secretion pathway?

Answer 40

M3 receptor

Question 41

What receptor does Gastrin bind to in the acid secretion pathway?

Answer 41

Cholecystokinin B (CKKB/CKK2) receptor

Question 42

What receptor does Histamine bind to in the acid secretion pathway?

Answer 42

H2 receptor

Question 43

Which pathway does ACh and Gastrin carry out acid secretion?

Answer 43

Act through G-coupled receptors | Increase in Ca2+ and diacylglycerol via PLC, IP3 pathway.

Question 44

Which pathway does Histamine carry out acid secretion?

Answer 44

G-coupled receptor to increase cAMP. | MOST powerful stimulus for HCl secretion

Question 45

What are the three phases of Acid Secretion Stimulation?

Answer 45

1) Celiac phase 2) Gastric phase 3) Intestinal phase

Question 46

What is the Celiac phase?

Answer 46

The Sight/Smell/Thought of food

Question 47

What is the Gastric phase?

Answer 47

When food is in the stomach and there is continuous secretion of HCl and pepsin Higher pH

Question 48

What is the Intestinial phase?

Answer 48

Chyme enters duodenum Duodenal stimulation of hormones Lower pH stimulates D cell activity

Question 49

Stomach distnetion via vagovagal reflex increases parietal cell acid by? (4 steps)

Answer 49

1) Direct stimulation of ECl to release histamine 2)Direct stimulation of G cells to release gastrin via GRP. 3)Inhibition of somatostatin release from D cells in antrum 4)Pyloric antrum exposure to peptides- G cells release gastrin >HCl by direct stimulation G cells and ECL histamine release

Question 50

What happens when there is too much acid?

Answer 50

Stimulation of D cells to release somatostatin and inhibits gastrin release to limit acid secretion.

Question 51

What are the 6 steps of HCl secretion?

Answer 51

1) CO2 diffuses into parietal cell from plasma 2) Combines with water to form carbonic acid 3) Carbonic acid dissociates into carbonate ions and H+ ions 4) H+/K+ ATPase actively transports H+ out, K+ in 5) K+ is recycled to gastric lumen via K+ channel 6) Cl- exists passively from cell via Cl- channel

Question 52

How does Mucosal Protection from HCl happen?

Answer 52

1) Vagal stimulation and irritation stimulate gastric mucous cells --> mucin

Question 53

What do gastric surface epithelial cells release?

Answer 53

HCO3-

Question 54

What stimulates epithelial cells?

Answer 54

ACh HCl PGs

Question 55

What happens to HCO3- released by Gastric epithelial surface cells?

Answer 55

Accumulate near the cell surface.

Question 56

What happens to mucin produced by the epithelial cells?

Answer 56

They are cleaved by pepsin