Digestive System- esophagus and GI

Question 1

what are the 4 layers of the alimentary canal?

Answer 1

mucosa
submucosa
muscularis
serosa

Question 2

what are the 3 layers of the mucosa of the alimentary canal?

Answer 2

lining epithelium
lamina propria
muscularis mucosa

Question 3

what are the 4 important functions of the mucosa?

Answer 3

secretion
absorption
barrier
immunological

Question 4

what antibodies does the mucosa secrete?

Answer 4

IgA

Question 5

what are the types of lymphatic tissue of the lamina propria of the mucosa?

Answer 5

peyer’s patches
GALT (Diffuse lymphatic + lymphatic nodules)
Eosinophils, neutrophils, macrophages

Question 6

what is the boundary between the mucosa and the submucosa?

Answer 6

muscularis mucosa

Question 7

what makes up the submucosa of the alimentary canal?

Answer 7

dense irregular connective tissue

Question 8

what is the extensive nerve plexus of the submucosa of the alimentary canal?

Answer 8

submucosal or Meissner’s plexus

Question 9

what glands are occasionally found in the submucosa of the alimentary canal?

Answer 9

submucosal glands

Question 10

what plexus is found in the muscularis layer of the alimentary canal?

Answer 10

Auerbach’s plexus / myenteric

Question 11

what movement of the muscularis moves things longitudinally only?

Answer 11

peristalsis

Question 12

what movement of the muscularis of the alimentary canal moves things proximally and distally?

Answer 12

segmentation

Question 13

what are the sphincters formed by the muscularis?

Answer 13

pyloric sphincter
ileocecal valve
internal anal sphincter

Question 14

what is the simple squamous epithelium of the serosa of the alimentary canal called?

Answer 14

mesothelium

Question 15

what is the serosa of the alimentary canal equivalent to in the body?

Answer 15

visceral peritoneum

Question 16

what kind of epithelium makes up the pharynx near the esophagus?

Answer 16

nonkeratinized stratified squamous epithelium

Question 17

what kind of epithelium makes up the pharynx near the nasal cavity?

Answer 17

pseudo-stratified ciliated columnar epithelium w/ goblet cells

Question 18

what is the muscularis in the esophagus at upper 1/3, middle 1/3, and lower 1/3?

Answer 18

upper- skeletal
middle- skeletal and smooth
lower- only smooth

Question 19

what is the mucosa of the esophagus?

Answer 19

stratified squamous epithelium

Question 20

what type of mucus is secreted from submucosal glands in the esophagus?

Answer 20

slightly acidic

Question 21

what do cardiac glands of the lower esophagus secrete?

Answer 21

neutral mucus

Question 22

what is the transition of epithelium in the esophagogastric junction?

Answer 22

from stratified squamous epithelium to columnar

Question 23

how are gastric glands formed?

Answer 23

gastric mucosa invaginates to form gastric pits

Question 24

what type of secretion do pyloric glands secrete?

Answer 24

viscous; probably mucous in nature

Question 25

what type of cells are found w/ pyloric glands?

Answer 25

enteroendocrine cells

Question 26

what do chief cells secrete?

Answer 26

pepsinogen and weak lipase

Question 27

pepsinogen is converted to what?

Answer 27

pepsin

Question 28

where are parietal cells found?

Answer 28

in the neck of fundic glands

Question 29

what is important about the membranes of the tubulovesicular system of parietal cells?

Answer 29

serve as a reservoir of active proton pumps

Question 30

what are the 3 receptors that iniate the release of HCl from the parietal cells?

Answer 30

Gastrin Acetylcholine M Histamine H2

Question 31

what factor is needed to combine w/ Vitamin B12 so it can be absorbed in the ileum?

Answer 31

intrinsic factor

Question 32

the absence of what lead to pernicious anemia?

Answer 32

parietal cells

Question 33

what is Vitamin B12 needed for?

Answer 33

RBC production and maintenance of CNS

Question 34

What peptide hormones are released by enteroendocrine cells from the fundus to the colon?

Answer 34

VIP | Somatostatin

Question 35

how long is the average lifespan of a mucosal cell?

Answer 35

3 to 5 days

Question 36

What is the main site for digestion and absorption?

Answer 36

small intestine

Question 37

Where can enzymes of the small intestine be found?

Answer 37

in the glycocalyx of the microvilli of the intestinal abosorptive cells (enterocytes)

Question 38

what are the 2 enzymes that mainly aid with lipid digestion?

Answer 38

pancreatic lipase and bile

Question 39

where is most of the lipid digestion in humans anatomically?

Answer 39

duodenum and ileum

Question 40

what gives actin in the microvilli its rigidity?

Answer 40

fascin | fimbrin

Question 41

what stabilizes the terminal web of the microvilli?

Answer 41

spectrin

Question 42

The presence of what in the terminal web determines that it can contract?

Answer 42

Myosin II and tropmyosin

Question 43

what does the terminal web of the enterocytes do to increase absorption?

Answer 43

it contracts to increase surface area to allow more absorption to occur

Question 44

what are the plicae circulares on the mucosal surface of the small intestine also known as?

Answer 44

valves of kerckring

Question 45

what are intestinal villi and what to do they do?

Answer 45

they are finger-like projections that cover the intestinal mucosa and function to increase SA

Question 46

what kind of epithelium do intestinal villi have?

Answer 46

simple columnar epithelilum w/ goblet cells interspersed

Question 47

what is at the middle of intestinal villi?

Answer 47

lacteals

Question 48

what is another name for intestinal glands?

Answer 48

crypts of Lieberkuhn

Question 49

where are brunner's glands found?

Answer 49

submucosa of the duodenum

Question 50

what do brunner's glands secrete?

Answer 50

alkaline secretions to neutralize acidic chyme

Question 51

which staining procedure will give a positive for glycoproteins present in mucus and the brush border of intestines?

Answer 51

PAS-hematoxylin

Question 52

what are the 5 mechanisms present in the alimentary canal for defense?

Answer 52

``` peyer's patches IgA paneth cells Acidity of gastric juices peristalsis ```

Question 53

what is the big role of paneth cells?

Answer 53

regulating the normal flora of small intestine

Question 54

what are the secretory granules that are present in paneth cells?

Answer 54

``` lysozyme alpha defensins glycoproteins arginine rich protein zinc ```

Question 55

What is the only AB that can be selectively passed across the mucosa tot he lumen?

Answer 55

IgA

Question 56

what does IgA bind?

Answer 56

toxins antigens microorganisms

Question 57

what is the pathology of crohn's disease?

Answer 57

Neutrophils, lymphocytes, and macrophages produces cytokines that cause damage to the intestinal mucosa

Question 58

what are the principal functions of the large intestine?

Answer 58

Reabsorption of water/ electrolytes | Elimination of undigested food/ waste

Question 59

what is the mucosa of the large intestine consist of?

Answer 59

goblet cells absorptive cells intestinal glands

Question 60

what does the pectinate line mark?

Answer 60

This line marks the junction b/w endodermal and ectodermal derivatives

Question 61

what epithelium is in the colorectal zone?

Answer 61

simple columnar epithelium

Question 62

what epithelium is in the anal transition zone?

Answer 62

simple columnar to stratified columnar to stratified squamous

Question 63

what epithelium is in the squamous zone?

Answer 63

stratified squamous

Question 64

what is the cause of Hirschsprung's disease?

Answer 64

Lack of neural crest cell migration to a segment of colon results in aganglionosis in which Meissner’s plexus and Auerbach’s plexus do not form ***