GIT Histology

Question 1

4 layers of the GI tract walls

Answer 1

mucosa, submucosa, muscularis externa, and serosa

Question 2

Components of the mucosa

Answer 2

Epithelium, lamina propria and muscularis mucosa

Question 3

What type epithelium lining is in the GIT for protection

Answer 3

stratified squamous

Question 4

Where is stratified squamos epithelium found

Answer 4

in the pharynx and esophagus

Question 5

What type epithelium lining is in the GIT for secretion

Answer 5

Simple columnar

Question 6

Where is simple columnar epithelium found

Answer 6

Stomach and intestines

Question 7

Responsible for IgA production, is found in the lamina propria

Answer 7

GALT (gut-associated lymphoid tissue

Question 8

What is the function of the muscularis mucosa

Answer 8

confers some motility to the

mucosa and facilitates discharge of secretions from glands

Question 9

Function of the submucosa

Answer 9

houses the larger blood vessels and

mucous-secreting glands

Question 10

2 layers of the muscularis externa

Answer 10

An inner

circular and an outer longitudinal

Question 11

Describe the muscualris externa in the upper 1/3 of the esophagus and the lower 1/3

Answer 11

The muscle is striated in the upper third of

the esophagus and smooth elsewhere.

Question 12

Layer of the epithelium that doubles to form mesentery

Answer 12

Serosa

Question 13

Location of Auerbach’s plexus

Answer 13

between the 2 muscle layers of the muscularis externa

Question 14

Plexus that is affected in Hirschsprung disease

Answer 14

Auerbach’s plexus ( deficiency of terminal

ganglion cells in the ganglia that affects digestive tract mobility)

Question 15

Location of intrinsic innervation in the GIT

Answer 15

within the walls of the GI tract

Question 16

What makes up the extrinsic innervation of the GIT

Answer 16

parasympathetic

(stimulatory) and sympathetic (inhibitory) axons

Question 17

Function of sensory fibers accompanying the parasympathetic nerves in the GIT

Answer 17

mediate visceral reflexes and sensations, such as hunger and rectal fullness

Question 18

Location of Brunners glands

Answer 18

Submucosa od duodenum

Question 19

Location of Peyer’s patches

Answer 19

Mucosa of Ileum

Question 20

Location of crypts of Lieberkuhns

Answer 20

Small and large intestines

Question 21

Location of gastric glands

Answer 21

Mucosa of stomach

Question 22

Section of the GIT that lack villi

Answer 22

Large intestines

Question 23

Location of plicae

Answer 23

Small and large intestines

Question 24

Location of most developed plicae

Answer 24

Jejunum

Question 25

Location of M cells found over lymphatic nodules and Peyer’s patches

Answer 25

Ileum

Question 26

Function of Mucous cells

Answer 26

Secrete mucous; form protective layer against | acid

Question 27

Function of Chief cells

Answer 27

Secrete pepsinogen and lipase precursor

Question 28

Function of Parietal cells

Answer 28

Secrete HCl and intrinsic factor

Question 29

Function of EE cells

Answer 29

High concentration of cells that secrete | cholecystokinin and secretin

Question 30

Function of Paneth cells

Answer 30

Contains granules that contain lysozyme

Question 31

Function of Goblet

Answer 31

Secrete acid glycoproteins that protect mucosal | linings

Question 32

Macrophage-like antigen-presenting | cells thatare present in the epithelial lining

Answer 32

Langerhans cells

Question 33

Function of intrinsic factor

Answer 33

necessary for absorption of vitamin B12

Question 34

Lack of absorption of Vitamin B12 leads to

Answer 34

pernicious anemia

Question 35

How is pepsinogen converted to pepsin

Answer 35

By acid

Question 36

Three substances that activate secretion of parietal cells

Answer 36

Ach, HCl increase by gastrin and histamine

Question 37

What is pepsinogen stored in in cheif ells

Answer 37

zymogen granules

Question 38

Which cell types are basophilic

Answer 38

Chief cells

Question 39

Which cell are acidophilic

Answer 39

Parietal cells

Question 40

What factors increase rate of mucous secretion

Answer 40

cholinergic stimulation, chemical | irritation, and physical irritation

Question 41

Function of Brunners glands

Answer 41

neutralize chyme from the stomach by neutral or alkaline mucous secretions

Question 42

From what two organs do the duodenum receive digestive enzymes and bicarbonate

Answer 42

pancreas and liver (bile)

Question 43

Function of enterocytes

Answer 43

Participate in the | final digestion steps and they absorb the digested food

Question 44

What nerve innervates the external anal sphincter

Answer 44

Pudenal nerve

Question 45

What is the Valsalva maneuver

Answer 45

Voluntary increase in intra-abdominal pressure