GI tract

Question 1

Is the GI tract permeable?

Answer 1

Yes, it is selectively permeable

Question 2

What is the oesophagus lined with and why?

Answer 2

Lined with non-keratinised stratified squamous cells
Because epithelial surface is not absorptive

Question 3

What provides protection for the oesophagus?

Answer 3

The non-keratinised stratified squamous cells
Provides protection as peristalsis propels food towards the stomach

Question 4

What provides the propulsion in the oesophagus?

Answer 4

Thick muscle layers

Question 5

Is the epithelial surface of the stomach absorptive?

Answer 5

Yes

Question 6

What is the simple glandular epithelium composed of in the stomach?

Answer 6

Gastric pits opening into deep gastric glands

Question 7

What do the gastric pits/gastric glands in the stomach contain?

Answer 7

Parietal cells which secrete hydrochloric acid
Pepsinogen secreting chief cells
Mucus producing goblet cells
enteroendocrine cells producing hormones

Question 8

What are the 3 types of muscle layer in the stomach?

Answer 8

Longitudinal
Circular
Oblique

Question 9

Why are mucus producing goblet cells important in the stomach?

Answer 9

Protect the lining because it is very acidic

Question 10

Where is the duodenum?

Answer 10

Small intestine

Question 11

What increases the surface area in the duodenum?

Answer 11

Villi and microvilli

Question 12

What is the duodenum lined with?

Answer 12

Simple columnar epithelial cells also with microvilli

Question 13

What is the submucosa in the duodenum filled with and what do they do?

Answer 13

Filled with Brunners glands
They release bicarbonate rich secretion into lumen to neutralise the acidic content release from the stomach - preventing an ulcer

Question 14

What muscle layers are there in the duodenum?

Answer 14

Longitudinal and circular

Question 15

Where are the jejunum and ileum?

Answer 15

Small intestine

Question 16

What lines the jejunum and ileum?

Answer 16

Simple columnar epithelium

Question 17

What does the submucosa in the jejunum and ileum contain?

Answer 17

Peyer’s patches which are large lymphoid aggregates

Question 18

What does the epithelium in the colon contain?

Answer 18

Large crypts of lieberkuhn lined by goblet cells

Question 19

How is the longitudinal layer of the muscle arranged in the colon?

Answer 19

Is organised into 3 thin bands called teniae coli - no longer forms a sheet of smooth muscle around the tube

Question 20

What do the teniae coli do in the colon?

Answer 20

contracts lengthwise to produce the haustra

Question 21

What is gastroscopy?

Answer 21

Camera tube inserted into mouth that can look at oesophagus, stomach and duodenum

Question 22

What is a colonoscopy?

Answer 22

Camera tube inserted in the anus, can look at whole colon to ileocecal valve

Question 23

What can continuous acid reflux lead to?

Answer 23

Dysplasia

Question 24

What can a helicobacter pylori chronic infection lead to?

Answer 24

Gastric ulcer

Question 25

How does the helicobacter plyori penetrate the mucus layer?

Answer 25

Using its shape and flagella

Question 26

What is the most common type of colorectum tumour?

Answer 26

Adenocarcinoma