GI III

Question 1

lacteal

Answer 1

lymphatic channels in core of the villus

Question 2

where does fat absorption take place

Answer 2

through the alcteal and conveyed to the larger lymphatic structures

Question 3

Function of smooth muscle within the lamina propria

Answer 3

contract and compress lacteal and move lymph from the lacteal to the lymphatic duct to the submucosa

Question 4

What do the plasma cells in the lamina propria secrete?

Answer 4

antibodies, specifically IgA

Question 5

What forms the intestinal glands (crypts of Liberkuhn)

Answer 5

epithelium invaginating into the lamina propria

Question 6

Where is the stem cell niche in the intestinal gland, and what takes place there

Answer 6

base of the gland

mitotic events

Question 7

Paneth cells

Answer 7

present at the bottom of the instinal glands
prominent acidophilic granules
granules contain lysozymes (which are bacteriolytic)

Question 8

Brunner’s glands

Answer 8

hallmark feature of duodenum
secrete alkaline mucus and human epidermal growth factor
don’t exist in jejunum

Question 9

human epidermal growth factor

Answer 9

stimulates cell proliferation

inhibits acid secretion from parietal cells

Question 10

Ileum

Answer 10

is flat
plicae circulares deminish in size
presence of peyer’s patches

Question 11

M cell

Answer 11

located in well-developed lymphatic nodules

involved in immune surveillance

Question 12

Teniae coli

Answer 12

3 longitudinal bands of muscularis externa that are found in the external aspect of the muscularis externa
not found in the rectum

Question 13

Haustra

Answer 13

present in the large intestine

Question 14

Plicae semilunares

Answer 14

semilunar folds

Question 15

Large intestine

Answer 15

lacks villi
brush border poorly developed
increased crypt density
increased goblet cell density
increased intestinal gland density
paucity of lymphatic vessels

Question 16

Mechanism of appendicitis

Answer 16

feaclith and intraluminal pressure

infection and mucosal ulceration

Question 17

Appenidix

Answer 17

lamina propria is rich in lymphatic tissue
muscularis extern has circular layer and outer longitudinal layer
villi absent

Question 18

Valves of houston/transverse rectal fold

Answer 18

3 permanent folds in the rectum
distal/inferior
middle
proximal/superior

Question 19

What is the function of the valves of houston

Answer 19

support and suspend the fecal mass until you poop

Question 20

What is the gut tube derived from ABOVE the pectinate line

Answer 20

hindgut

Question 21

what is the gut tube BELOW the pectinate line derived from

Answer 21

the proctodeum

Question 22

What is the innervation above the pectinate line

Answer 22

autonomic (no pain)

Question 23

What is the innervation below the pectinate line

Answer 23

somatic

Question 24

Where does cancer below the pectinate canal drain?

Answer 24

into the inguinal nodes

Question 25

Layers of the anal canal from the lumen out

Answer 25

simple columnar epithelia w/large population of goblet cells muscularis mucosae submucosae

Question 26

Submucosae of anal canal

Answer 26

contains internal hemorrhoidal (venous) plexus | plexus found in three anal columns called anal cushions

Question 27

Anal columns

Answer 27

ridges projecting into lumen

Question 28

What are the three anal cushions

Answer 28

left lateral right anterior right posterior (named as if the patient is in a supine position)

Question 29

Where do hemorrhoids develop

Answer 29

in the anal cushion

Question 30

Bottom of columns join together and form a wall called what

Answer 30

anal valves

Question 31

What is the name for the depressions at distal end of the columns

Answer 31

anal sinuses

Question 32

Anal sinuses

Answer 32

glandular secretions accumulate here | glands here can become infected and cause an anorectal abscess

Question 33

What are the epithelia transitions dital to the pectinate line

Answer 33

simple columnar stratified squamous non-keratinized epithelia stratified squamous keratinized epithelia

Question 34

Interspincteric groove (white line of HIlton)

Answer 34

ring-like depression just below pectinate line | represents the border between the internal and external anal sphincters

Question 35

What is the most common anorectal abscess

Answer 35

perianal

Question 36

Anorectal abscess

Answer 36

gland secretions and/or fecal matter plugging up anal sinuses, leading to inflammation and infection. Pockets up pus (abscesses) accumulate

Question 37

Fistula in ano

Answer 37

when anorectal abscesses develop in tubes which penetrate from anal canal to the skin of perineum.

Question 38

What are locations of fistula in ano from most to least common

Answer 38

1. intersphincteric 2. transspincteric 3. suprasphincteric

Question 39

Colonic DIverticula

Answer 39

happens in large intestine only found at sights of weakness between tenia coli formed by out pouching of mucosa and submucosa

Question 40

False diverticula involve _____ and ______

Answer 40

mucosa | submucosa

Question 41

True diverticula involves _____

Answer 41

all layers | ex) Meckel's diverticulum

Question 42

What is a common site for polyps?

Answer 42

large intestine

Question 43

Why do polyps develop

Answer 43

due to hyperproliferation of cells | Larger it is, more likely to be invasive

Question 44

Lymphatic vessels in the lamina propria of the large intestine

Answer 44

are poorly developed | are better developed in the presence of inflammatory bowel disease

Question 45

Ulcerative colitis

Answer 45

typically confined to large intestine

Question 46

Crohn's Disease

Answer 46

found anywhere along GI tract | much more likely to cause fissures and fistula

Question 47

Hirschsprung's disease will always involve what?

Answer 47

rectum

Question 48

Hirschsprung's disease (aka congenital megacolon)

Answer 48

neural crest cells do not migrate properly into involved segment of colon Will show a lack of myenteric and submucosal plexus causes area to remain constricted