Digestive Histology

Question 1

GI tract layers (deep to superficial)

Answer 1

mucosa

submucosa

tunica muscularis

tunica serosa/adventitia

Question 2

three layers/parts of mucosa

Answer 2

surface epithelium
lamina propria
muscularis mucosae

Question 3

three parts of submucosa

Answer 3

dense irregular fibroelastic CT
blood and lymph
Meissner’s plexuses

Question 4

what are Meissner’s plexuses for?

Answer 4

motility and secretion of glands

Question 5

what does the tunica muscularis do?

Answer 5

moves contents of the lumen

Question 6

inner layer of tunica muscularis is _______ smooth muscle

outer layer is ______ smooth muscle

Answer 6

circular

longitudinal

Question 7

where are Auerbach’s plexuses and what do they do?

Answer 7

in tunica muscularis, between layers of muscularis externa

regulate activity of muscularis externa

Question 8

tunica that is connected to body wall is called ______

tunica that is connected to visceral peritoneum is called _______

Answer 8

adventitia

serosa

Question 9

in esophagus tunica muscularis:

cranial 1/3 is ____
middle 1/3 is ____
distal 1/3 is ____

Answer 9

skeletal

skeletal and smooth

smooth

(voluntary to involuntary control)

Question 10

environment of stomach is regulated by hormome ____

Answer 10

ghrelin (creates sensation of hunger)

Question 11

bolus of food is mixed with gastric juices and churned in to

Answer 11

chyme

Question 12

relaxes smooth muscle lining of stomach to receive a bolus of food

Answer 12

ghrelin

Question 13

longitudinal folds in the mucosa of the stomach that permit expansion

Answer 13

rugae

Question 14

4 anatomical areas of stomach

Answer 14

cardia
fundus
body
pylorus

Question 15

rugae are shallow in _____ and deepest in ______

Answer 15

cardia

pyloric region

Question 16

rugae with epithelia lining form

Answer 16

gastric pits to increase surface area

Question 17

at bottom of gastric pits are ________ with these special cells (6)

Answer 17

gastric glands

surface-lining cells - protect from autodigestion

regenerative cells - replace all specialized cells in 5-7 days

mucous neck cells - lubricate lining of stomach

parietal cells - secrete HCL and gastric inhibiting factor

chief cells - pepsinogen and leptin

diffuse neuroendocrine system cells (DNES) - secrete hormones

Question 18

mucosa of stomach contains (3)

Answer 18

simple columnar epithelium - surface-lining cells

gastric glands opening into bottom of gastric pits

lamina propria - loose fibrous tissue surrounding gastric glands

Question 19

3 layers of smooth muscle in tunica muscularis of stomach

Answer 19

inner oblique, middle circular, and outer longitudinal

Question 20

gastric juices are composes of:

Answer 20

water
HCL and gastric intrinsic factor
enzymes (pepsinogen)
glycoprotein
soluble mucus

Question 21

when is pyloric sphincter CLOSED?

Answer 21

only when peristalsis of stomach is happening

Question 22

pyloric sphincter and stomach movement is regulated by

Answer 22

Gastrin

Question 23

3 modifications to increase surface area in small intestine

Answer 23

plicae circulares (mucosal/submucosal folds)

villi

microvilli (brush border)

Question 24

Crypts of Lieberkuhn are found where

Answer 24

mucosa of SI

Question 25

Brunner’s glands are found where

Answer 25

submucosa of duodenum

Question 26

cells found in epithelium of small intestine mucosa (3)

Answer 26

surface absorptive cells

goblet cells

DNES cells - produce hormones

Question 27

most numerous cells of the small intestine; apical surface makes brush border

Answer 27

surface absorptive cells

Question 28

what is the brush border

Answer 28

3000 microvilli to protect against autodigestion

Question 29

villi are only found where?

Answer 29

in small intestine

Question 30

finger/leaf-shaped projections of lumen in to small intestine

Answer 30

villi

Question 31

enterocytes originate in ______ from _____ and migrate along basement membrane to villus tip to become ______

Answer 31

crypts from germinative cells

absorptive cells

Question 32

simple tubular glands in small intestine that are continuous with villi and a major source of fluid secretion in teh gut

Answer 32

Crypts of Lieberkuhn

Question 33

cells that line crypts of lieberkuhn (5)

Answer 33

surface absorptive cells

goblet cells

regenerative cells

paneth cells (manufacture lysozyme)

DNES cells

Question 34

the connective tissue core of villi in the small intestine

Answer 34

lamina propria

Question 35

middle of villi is a lymphatic channel called a

Answer 35

lacteal

Question 36

serous glands that pierce the base of crypts of lieberkuhn in duodenum

Answer 36

Brunner’s glands

Question 37

what do Brunner’s glands secrete?

Answer 37

basic fluid to neutralize gastric acid and epidermal growth factor to maintain enterocyte growth/health

Question 38

shortest segment of SI

largest and most numerous villi

fewest goblet cells

Answer 38

duodenum

Question 39

longest segment of SI

Answer 39

jejunum

Question 40

segment of SI with fewest and shortest villi and the most goblet cells. Also contains Peyer’s patches

Answer 40

ileum

Question 41

in small intestine, mixing contractions and propulsive contractions together can cause a

Answer 41

peristaltic rush (rush of chyme into colon)

Question 42

how much fluid is absorbed by SI each day?

Answer 42

6-7 liters

Question 43

what does the colon and cecum do?

Answer 43

absorbs most of the water and compacts chyme into feces

Question 44

colon has lots of _____ in epithelium

Answer 44

goblet cells

Question 45

crypts of lieberkuhn in LI do not contain

Answer 45

paneth cells

Question 46

at anal canal tissue transitions from ____ to _____

Answer 46

simple columnar epithelium

stratified squamous epithelium

Question 47

disease in which “cobblestoning” happens when ulcers separate the mucosa and give it a cobblestone appearance

Answer 47

Crohn’s disease