Digestive System- esophagus and GI Flashcards Preview

Cell Bio Block 3 > Digestive System- esophagus and GI > Flashcards

Flashcards in Digestive System- esophagus and GI Deck (64):
1

what are the 4 layers of the alimentary canal?

mucosa
submucosa
muscularis
serosa

2

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

lining epithelium
lamina propria
muscularis mucosa

3

what are the 4 important functions of the mucosa?

secretion
absorption
barrier
immunological

4

what antibodies does the mucosa secrete?

IgA

5

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

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

6

what is the boundary between the mucosa and the submucosa?

muscularis mucosa

7

what makes up the submucosa of the alimentary canal?

dense irregular connective tissue

8

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

submucosal or Meissner's plexus

9

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

submucosal glands

10

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

Auerbach's plexus / myenteric

11

what movement of the muscularis moves things longitudinally only?

peristalsis

12

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

segmentation

13

what are the sphincters formed by the muscularis?

pyloric sphincter
ileocecal valve
internal anal sphincter

14

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

mesothelium

15

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

visceral peritoneum

16

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

nonkeratinized stratified squamous epithelium

17

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

pseudo-stratified ciliated columnar epithelium w/ goblet cells

18

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

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

19

what is the mucosa of the esophagus?

stratified squamous epithelium

20

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

slightly acidic

21

what do cardiac glands of the lower esophagus secrete?

neutral mucus

22

what is the transition of epithelium in the esophagogastric junction?

from stratified squamous epithelium to columnar

23

how are gastric glands formed?

gastric mucosa invaginates to form gastric pits

24

what type of secretion do pyloric glands secrete?

viscous; probably mucous in nature

25

what type of cells are found w/ pyloric glands?

enteroendocrine cells

26

what do chief cells secrete?

pepsinogen and weak lipase

27

pepsinogen is converted to what?

pepsin

28

where are parietal cells found?

in the neck of fundic glands

29

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

serve as a reservoir of active proton pumps

30

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

Gastrin
Acetylcholine M
Histamine H2

31

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

intrinsic factor

32

the absence of what lead to pernicious anemia?

parietal cells

33

what is Vitamin B12 needed for?

RBC production and maintenance of CNS

34

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

VIP
Somatostatin

35

how long is the average lifespan of a mucosal cell?

3 to 5 days

36

What is the main site for digestion and absorption?

small intestine

37

Where can enzymes of the small intestine be found?

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

38

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

pancreatic lipase and bile

39

where is most of the lipid digestion in humans anatomically?

duodenum and ileum

40

what gives actin in the microvilli its rigidity?

fascin
fimbrin

41

what stabilizes the terminal web of the microvilli?

spectrin

42

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

Myosin II and tropmyosin

43

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

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

44

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

valves of kerckring

45

what are intestinal villi and what to do they do?

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

46

what kind of epithelium do intestinal villi have?

simple columnar epithelilum w/ goblet cells interspersed

47

what is at the middle of intestinal villi?

lacteals

48

what is another name for intestinal glands?

crypts of Lieberkuhn

49

where are brunner's glands found?

submucosa of the duodenum

50

what do brunner's glands secrete?

alkaline secretions to neutralize acidic chyme

51

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

PAS-hematoxylin

52

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

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

53

what is the big role of paneth cells?

regulating the normal flora of small intestine

54

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

lysozyme
alpha defensins
glycoproteins
arginine rich protein
zinc

55

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

IgA

56

what does IgA bind?

toxins
antigens
microorganisms

57

what is the pathology of crohn's disease?

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

58

what are the principal functions of the large intestine?

Reabsorption of water/ electrolytes
Elimination of undigested food/ waste

59

what is the mucosa of the large intestine consist of?

goblet cells
absorptive cells
intestinal glands

60

what does the pectinate line mark?

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

61

what epithelium is in the colorectal zone?

simple columnar epithelium

62

what epithelium is in the anal transition zone?

simple columnar to stratified columnar to stratified squamous

63

what epithelium is in the squamous zone?

stratified squamous

64

what is the cause of Hirschsprung's disease?

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 ***