7 Histo of the SI + LI

Question 1

Where a GI organ is covered in peritoneum, the outermost layer is called

Answer 1

Serosa

Question 2

The small intestine is characterized by what kind of crypts

Answer 2

Lieberkuhn

Question 3

What are the ways in which the SI functions to increase SA

Answer 3

Vili
Plica circularis (similar to rugae)
Microvilli (only found in SI)

Question 4

What does the villus capillary plexus of the SI supply

Answer 4

Intestinal villus and upper portion of crypts of lieberkuhn

Question 5

What does the pericryptal capillary plexus supply in the SI

Answer 5

Lower half of crypts of liberkuhn

Question 6

What do lacteals do

Answer 6

They are lymphatic vessels that can form GALT and function to transport fats

Question 7

Where is the plexus of meissner

Answer 7

Submucosa layer

Question 8

Where is the myenteric plexus of auerbach

Answer 8

In between the inner circular muscularis layer and the outer longitudinal layer

Question 9

What glands are characteristic of the duodenum

Answer 9

Brunner’s glands in the submucosa

Question 10

What do bruner’s glands do

Answer 10

Produce an alkaline secretion to neutralize acidic stomach contents

Question 11

What is a major characteristic of the gastroduodenal junction

Answer 11

Thick wall of muscle at the pyloric sphincter

Deep glands can be found in the duodenum

Question 12

What does the jejunum’s villi look like

Answer 12

They are longer than the ileum and they have developed lacteals underneath

Question 13

What is the difference between the jejunum and the duodenum

Answer 13

The jejunum lacks Brunner’s glands

Question 14

What does the jejunum not have that the ileum has

Answer 14

Peyer’s patches (developed lymph nodules)

Question 15

How do the villi of the jejunum and the ileum compare

Answer 15

Ileum has shorter and less plentiful villi

Question 16

What parts of the GI have paneth cells

Answer 16

Ileum and jejunum

Question 17

Where are paneth cells found in the ileum

Answer 17

Base of the crypts of lieberkuhn

Question 18

What type of cells are found within SI glands and crypts

Answer 18

Enteroendocrine cells, paneth cells, intestinal stem cells

Question 19

What is the surface of microvilli sometimes called

Answer 19

Brush border

Question 20

What holds up the microvilli so they remain upright

Answer 20

Terminal web (cytoskeletal filaments)

Question 21

What cell type appear to have microvilli but do not?

Answer 21

Goblet cells

Question 22

The apical domain of goblet cells is characterized by what

Answer 22

Large mucus granules

Question 23

The basal domain of goblet cells is characterized by what

Answer 23

rER, golgi, and nucleus to ship all the mucus granules

Question 24

What is the function of intestinal mucus

Answer 24

Hydrates intestinal mucus and forms a protective coat to shield from abrasion and bacterial invasion

Question 25

What do the enteroendocrine cells of the SI secrete

Answer 25

Gastrin, secretin, cholecystokinin

Question 26

What does secretin do

Answer 26

Stimulates bicarb secretion by pancreas Enhances insulin secretion by β cells in the islets of langerhans

Question 27

Wha does cholecystokinin do

Answer 27

Slows down emptying of stomach by acting on pyloric sphincter Stimulates bile release from gallbladder and the secretion of pancreatic enzymes

Question 28

What does gastrin do

Answer 28

Stimulates secretion of hydrochloric acid by parietal cells Stimulates insulin secretion Stimulates gastric motility and growth of mucosal cells

Question 29

What are paneth cells

Answer 29

Pyramidal shaped cells that secrete anti-microbial proteins (defensins, lysozyme, angiogenin 4)

Question 30

What types of cells do intestinal stem cells produce

Answer 30

Goblet cells, enterocytes, enteroendocrine cells

Question 31

What is the function of the LI

Answer 31

Absorb water, Na, vitamins, minerals Uptake of sedatives, anesthetics, steroids

Question 32

What are found in SI that are not found in the LI

Answer 32

Plicae circulares and intestinal villi

Question 33

Where are paneth cells found in the LI

Answer 33

Cecum

Question 34

What does the muscularis of the LI contain

Answer 34

Taeniae coli that form haustra

Question 35

What does the serosa of the LI contain

Answer 35

Appendices or fat tags related to a person’s weight

Question 36

How is the appendix different from the LI

Answer 36

The submucosa of appendix contains adipocytes and outer longitudinal layer is not well developed

Question 37

What is the cause of hirshprung’s disease

Answer 37

Missing myenteric or submucosal n plexuses

Question 38

What causes the aganglionosis in hirschprung’s disease

Answer 38

Failure of NCC to develop

Question 39

What mutation causes the aganglionosis of hirschprung’s disease

Answer 39

RET gene encoding a RTK

Question 40

What does the RET gene do in the colon

Answer 40

Required for: - formation of peyer’s patches - migration of NCC to LI - differentiation of neurons in enteric NS

Question 41

What does a biopsy from hirschprung’s show

Answer 41

Thick, irregular nerve bundles and abundant AChE staining

Question 42

The upper part of the rectum is characterized by what? Lower part

Answer 42

Mucosa and tubular glands 8-10 rectal/anal columns forming anal valves -base of anal columns is pectinate line

Question 43

What cell types are found at the pectinate line?

Answer 43

Proximal - simple columnar Distal - stratified squamous

Question 44

What is the skeletal muscle in the anal sphincter

Answer 44

External anal sphincter