5. Histology of the Small and Large Intestine

Question 1

What glands are located in the submucosa of the duodenum?

Answer 1

Brunner’s glands

Question 2

What is the function of Brunner’s glands?

Answer 2

Secretion of an alkaline fluid to neutralize acidic chyme.

Question 3

How many submucosal glands do we find in the jejunum?

Answer 3

The jejunum has no submucosal glands.

Question 4

What glands can be found in the submucosa of the stomach?

Answer 4

There are no submucosal glands in the stomach. The gastric glands are located in the gastric mucosa.

Question 5

What do we call the lymphatic structure that assists with the absorption of fat in the intestinal villi?

Answer 5

Lacteal

Question 6

Where are paneth cells unique to?

Answer 6

The small intestine.

(Specifically the base of the intestinal glands in the small intestine)

Question 7

Where are Brunner’s glands located histologically?

Answer 7

In the submucosa of the duodenum

Question 8

What cells of the small intestine secrete lysozyme, alpha-defensins, and other glycoproteins for antimicrobial defense?

Answer 8

Paneth cells

Question 9

What prevents the plicae circulares from ever laying completely flat?

Answer 9

The plicae circulares have a submucosal core

Question 10

Histologically speaking, where are intestinal glands found?

Answer 10

Throughout the mucosal layer of the entire small intestine

Question 11

If you’re looking at a section of small intestine, and you see no Peyer’s patches and no Brunner’s glands, what section of the small intestine are you looking at?

Answer 11

The Jejunum

Question 12

Which part of the intestine typically has the longest villi?

Answer 12

The jejunum

Question 13

What do we call the simple columnar cells of the large intestine?

Answer 13

Colonocytes

Question 14

What is the primary indicator histologically of a slide coming from the colon?

Answer 14

A multitude of goblet cells without villi

Question 15

What layer, in the colon, forms the tinea coli?

Answer 15

The outer longitudinal layer of the muscularis externae

Question 16

What protein is defective in Hirschprung’s disease?

Answer 16

The RET gene, which is responsible for neural crest cell development

Question 17

What is the basic pathophysiology of Hirschsprung’s disease?

Answer 17

Neural crest cells fail to differentiate causing an absence of the plexus of Auerbach in the colon. This results in absent peristalsis, and leads to megacolon through impactions.

Question 18

What is the most common type of Hirschsprung’s disease?

Answer 18

“Short segment disease” – where the issue is confined to the “rectosigmoid region” (rectum and sigmoid colon).

Question 19

What two diseases are included in the term Inflammatory Bowel Disease?

Answer 19

Ulcerative colitis and Crohn’s disease

Question 20

What histological region is affected by ulcerative colitis?

Answer 20

Specifically the mucosa of the large intestine.

Question 21

Where is damage from Crohn’s disease localized?

Answer 21

The terminal ileum

(However it has been observed in the large intestine as well)

Question 22

What are the three divisions of the anal canal?

Answer 22

The colorectal zone, the anal transitional zone, and the squamous zone.

Question 23

Where does the enteric nervous system end?

Answer 23

At the anal transitional zone of the anal canal

Question 24

Where are anal glands found?

Answer 24

Extending into the submucosa and muscularis externa of the anal canal.

Question 25

What are the anal columns formed from?

Answer 25

Mucosal folds of the anal canal

Question 26

What type of glands are the circumanal glands?

Answer 26

Simply apocrine sweat glands in humans