Histology of GI Tract

Question 1

what 2 things happen bidirectionally across the wall of the GI tract?

Answer 1

secretion & absorption

Question 2

parasympathetic fibers innervate the __________ and _______ of the viscera

Answer 2

smooth muscle; glands

Question 3

sympathetic fibers innervate smooth muscles of _________ and abdominal viscera

Answer 3

blood vessels

Question 4

true or false?
sympathetic fibers inhibit parasympathetic stimulation

Answer 4

true

Question 5

what are the 2 main plexuses of the enteric nervous system?

Answer 5

submucosal (meissner) and myenteric (auerbach)

Question 6

where is the myenteric plexus located?

Answer 6

between layers of muscularis externa

Question 7

the myenteric and submucosal plexuses are interconnected networks of _________

Answer 7

ganglia

Question 8

innervates vessels of submucosa and muscularis mucosae

Answer 8

submucosal plexus

Question 9

innervates smooth muscle of muscularis externa

Answer 9

myenteric plexus

Question 10

which layer of the digestive tract faces the lumen?

Answer 10

mucosa

Question 11

The epithelium of the esophagus is unique compared to the rest of the GIT. It has ______ epithelium, whereas the rest of the tract has ______ epithelium

Answer 11

squamous; columnar

Question 12

underlying connective tissue of the mucosa containing glands, blood/lymph vessels, and immune system components

Answer 12

lamina propria

Question 13

the muscularis mucosae borders the _______

Answer 13

submucosa

Question 14

what is the function of muscularis mucosae contraction?

Answer 14

moves mucosa to facilitate absorption/secretion

Question 15

dense irregular connective tissue w/ larger blood/lymph vessels can be found in which layer of the GI tube?

Answer 15

submucosa

Question 16

muscularis externa is comprised of layers of _____ muscle

Answer 16

smooth

Question 17

inner layer of muscularis externa contains ____ smooth muscle

Answer 17

circular

Question 18

outer layer of muscularis externa contains ______ smooth muscle

Answer 18

longitudinal

Question 19

coordinated/synergistic contraction of the muscularis externa to propel contents through the tube is called?

Answer 19

peristalsis

Question 20

involves breaking food into smaller chunks so that it’s easier to digest and to increase surface area contact

Answer 20

segmentation

Question 21

sphincter located at the inferior end of the esophagus that functions to prevent reflux

Answer 21

inferior (lower) esophageal sphincter

Question 22

sphincter located at the junction of the pylorus and duodenum that controls the release of chyme

Answer 22

pyloric (gastroduodenal) sphincter

Question 23

combination of food and gastric juice

Answer 23

chyme

Question 24

valve located at the junction of small and large intestines that functions to prevent contents of the colon from refluxing into distal ileum

Answer 24

ileocecal valve

Question 25

sphincter surrounding the anal canal that prevents passage of feces from the rectum into the anal canal

Answer 25

internal anal sphincter

Question 26

sphincter located at the junction between the pharynx and esophagus that prevents air from entering esophagus + the reflux of food into airway

Answer 26

superior (upper) esophageal sphincter

Question 27

sphincter that is part of the pelvic floor & functions to keep stool in the anal canal until ready for defecation… voluntary skeletal muscle

Answer 27

external anal sphincter

Question 28

outer layer of the GI tube; thin layer of loose connective tissue and mesothelium

Answer 28

serosa

Question 29

simple squamous cells of peritoneum, pericardium, and pleura

Answer 29

mesothelium

Question 30

in the abdomen, the serosa is called ?

Answer 30

visceral peritoneum… continuous w/ mesentery and parietal peritoneum