GIT Flashcards by Munieh A

What do the salivary glands secrete?

Amylase
lipase
mucin

How well did you know this?

Not at all

Perfectly

What is the role of mucin?

Aids lubrication and swallowing of material

How well did you know this?

Not at all

Perfectly

What are the 3 sets of salivary glands called?

Sublingual
Submandibular
Parotid

How well did you know this?

Not at all

Perfectly

Which virus infects the salivary glands, in particular the parotid glands?

Mumps

How well did you know this?

Not at all

Perfectly

What is dysphagia and how is it caused?

Difficulty swallowing - caused by damage to nerves

How well did you know this?

Not at all

Perfectly

What is the function of the lower oesophageal sphincter?

Contract and seal the top of the stomach to prevent acid from passing into oesophagus

How well did you know this?

Not at all

Perfectly

What is Barret’s oesphagus?

When normal squamous epithelial cells are replaced with abnormal specialised columnar cells which are cancerous. This happens as a result of cells being exposed to stomach acid

How well did you know this?

Not at all

Perfectly

Patients with Barrett’s oesophagus are less likely to get adenocarcinoma. True or false?

False - at increased risk - even if reflux is controlled and the oesophagus heals - the cancerous cells remain

How well did you know this?

Not at all

Perfectly

What do g cells secrete?

gastrin - this stimulates secretion of acid

How well did you know this?

Not at all

Perfectly

Where are G-cells found?

In the stomach antrum

How well did you know this?

Not at all

Perfectly

Where are chief cells found?

in the stomach fundus/body

How well did you know this?

Not at all

Perfectly

What do chief cells secrete?

Pepsinogen and lipase

How well did you know this?

Not at all

Perfectly

What do the parietal cells secrete?

Acid (HCl)

How well did you know this?

Not at all

Perfectly

What is the role of gastric lipase?

Converts triglycerides into monoglycerides

How well did you know this?

Not at all

Perfectly

What are the 4 types of gastric cells?

Mucous cells
G cells
Chief cells
Parietal cells

How well did you know this?

Not at all

Perfectly

Pepsinogen is converted into pepsin when it comes into contact with what?

HCl

How well did you know this?

Not at all

Perfectly

How are H2 receptors involved in the secretion of gastric acid?

Stretch of the stomach upon entry of food causes the release of histamine which binds to histamine receptors and causes the release of HCl

How well did you know this?

Not at all

Perfectly

What are the ways in which gastric acid is produced in the stomach?

proton pump secretes acid
site and smell of food triggers receptors and impulses go into brain. The brain fires impulses down neurone into stomach. When these arrive in stomach, ACh is released and binds to receptor causing release of HCl from parietal cells
G-cells produce gastrin which stimulates release of HCl
Stretch of stomach upon entry of food releases histamine and causes release of HCl

How well did you know this?

Not at all

Perfectly

What are the drug classes that can reduce stomach acid secretion?

H2 receptor antagonists

PPIs

How well did you know this?

Not at all

Perfectly

Name a H2 receptor antagonist

Ranitidine

Climetidine

How well did you know this?

Not at all

Perfectly

Name a PPI

Omeprazole

How well did you know this?

Not at all

Perfectly

Proton pump inhibitors reversibly bind to SH group of the proton pump. True or false?

False - irreversibly bind

How well did you know this?

Not at all

Perfectly

What is the role of carbonic anhydrase in a parietal cell?

It catalyses the combination of carbon dioxide and water to form carbonic acid
It also splits carbonic acid into bicarbonate and protons

How well did you know this?

Not at all

Perfectly

What prevents the stomach form digesting itself?

Pepsinogen (pepsin protease secreted in the inactive form)

How well did you know this?

Not at all

Perfectly

The stomach secretes HCl. What 3 factors prevent the stomach from suffering from burns as a result?

Mucus secretion Tight junctions High cell turnover throughout the GIT

How does mucus protect the stomach from acidic conditions:?

It is alkaline so neutralises acid. It forms a barrier, stopping pepsin getting through and digesting underlying tissue

What is the role of tight junctions in the stomach?

They lock epithelial cells together and so restrict movement of acid/protease to underlying tissue

Why is the high cell turnover throughout the GIT beneficial to the stomach?

damaged cells are frequently replaced with cells from gastric pits

What is peritonitis and how is it caused?

Inflammation of the lining of the peritonea as a result of a bacterial infection due to perforated ulcer

Peritonitis is a medical emergency and requires hospitalisation. True or false?

True

How can H.pylori lead to ulcer formation?

It infects the gastric mucosa leading to a decrease in barrier efficiency leading to ulcer formation

What are the 3 surgical procedures for obesity?

Gastric sleeve Gastric band Roux en Y bypass

What is peristalsis?

Wave of muscular contraction that pushes material in the lumen along the intestine

How does targeting longitudinal muscles help in treatment of diarrhoea?

Retain contents in GIT longer so there is an increase in water absorption and the consistency of contents changes

What drug is used for treatment of diarrhoea?

Loperamide

Targeting M_____ P______ will reduce the activity of longitudinal muscles

Myenteric plexus

Where are bile acids produced?

Liver

What are bile acids important for the absorption of?

Lipids and for lipid emulsification

Which vitamins are lipid soluble vitamins?

A, D, E and K

Where are bile acids stored?

Gall bladder

Ulcers develop where there is an imbalance between the agents that protect the stomach and those that attack it. True or false?

True

Reflux may cause chronic cough and laryngitis and is associated with asthma. True or false?

True

What group of drugs is the first choice for dyspepsia and mild symptoms of GORD?

Antacids and alginates

H2 receptor antagonists bind irreversibly. True or false?

False - reversible

A side effect of magnesium containing antacids is constipation. True or false?

False - antacids containing aluminium

What is a side effect of antacids containing magnesium?

Laxative effect- stools may become looser

Antacids have high sodium content. This may be a problem for which groups of patients?

Those on a salt restricted diet Pregnant women Renal and cardiac conditions Hypertension

What is the definition of low sodium?

sodium content of less than 1mmol per tablet of 10ml dose

Why can antacids damage enteric coating of other drugs, if taken together?

Because they will raise the pH as they neutralise acid

H2 antagonists are able to heal duodenal and gastric ulcers at low doses. True or false?

False - at high doses

H2 antagonists are not available OTC. True or false?

False - available OTC in low doses

H2 antagonists are more effective than PPIs in treatment of GORD. True or false?

False - less effective

H2 antagonists are licensed for NSAID prophylaxis. True or false?

True - they prevent NSAIDs causing ulceration

Which H2 antagonist interacts with warfarin?

Cimetidine - it inhibts its metabolism and increases INR

Cimetidine interacts with which PDE inhibitor?

Theophylline

Nearly all duodenal ulcers and most gastric ulcers not associated with NSAIDs are caused by H.pylori. True or false?

True

H.pylori produces an antibody response. What tests can detect this?

Serum Saliva Urine

Antibody tests for H.pylori can be done after eradication therapy. True or false?

False - antibody titre could still be high even after infection has been cleared

How many days is eradication therapy for H.pylori?

What does presence of symptoms after eradication of H.pylori indicate?

GORD

How can NSAID associated ulcers be treated?

PPI H2 antagonist Misoprostol (3rd line)

The epithelium of the small intestine is one cell thick. True or false?

True

Which cells in the epithelium of the small intestine secrete mucus?

Goblet cells

What is the role of sucrase?

Breaks down sucrose into glucose and fructose

What is the role of lactase?

Breaks down lactose into glucose and galactose

What is the role of maltose?

Breaks down maltose into glucose and glucose

Which transporter protein transports glucose and galactose into the enterocytes?

SGLT1

For glucose and galactose to be absorbed in the intestine, what needs to be present?

Sodium

Which transporter transports fructose into the enterocytes?

GLUT5

The transport of fructose is sodium independent. True or false?

True

What transporter transports small peptides and what ion needs to be present for this to happen?

PEPT1 - happens in presence of H+ ions

Penicillin is a substrate of which uptake transporter?

PEPT1

Enalapril is a susbtrate for which uptake transporter?

PEPT1

Which transporter uptakes cephalosporins?

PEPT1

Val-acyclovir can only be transported via PEPT1 transporter. True or false?

False - PEPT1 and OCTN2

Pravastatin is a substrate for which uptake transporter?

OATP2B1

Quinidine is a susbtrate for which uptake transporter?

OCTN2

Fexofenadine is a substrate for which uptake transporter?

OATP2B1

Valproic acid is taken up by which uptake transporter?

OCTN2

Imatinib is taken up by which uptake transporter?

OCTN2

What are the 2 major efflux transporters?

P-gp | BCRP

BCRP is only found in breast cancer. True or false?

False - found throughout the body

Name some p-gp substrates

Antibiotics Immunosuppressants HIV PI Cardiotonics

Digoxin is safe to take with atorvastatin. True or false?

False - they interact, resulting in an increase in digoxin AUC

Digoxin interacts with ritonavir. True or false?

True

Digoxin interacts with talinolol. True or false?

True