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DEMS: Unit 1 > GI Histology > Flashcards

Flashcards in GI Histology Deck (64):
1

Types of cells lining the oral cavity

  • stratified squamous epithelium
    • non-keratinized, except @ hard palate

2

Types of salivary glands and location

  • salivary glands = exocrine glands = secrete products into lumen via duct system
  • submanidbular 
  • sublingual
  • parotid
  • similar structures but different types secretory units (acini)

3

Cell type & location

  • stratified squamous epithelium
  • oral cavity

4

  • A = parotid gland
  • B = sublingual gland
  • C = submandibular

5

Types of acini

  • acini = structural unit of secretory tlands which form lumens continuous w/duct system
  • serous acini
    • secretory product = mostly digestive enzymes and fluid
  • mucous acini
    • secretory product = extensively glycosylated proteins that fxn in lubrication of ingested food
  • mixed acini (inner = mucous, outer = serous)

6

Histologic characteristics of submandibular salivary gland

  • serous and mucous acini; serous predominate
  • gland is subdivided by connective tissue septa
  • serous-secreting sections = darker
  • mucous-secreting sections = lighter

7

Histological characteristics of sublingual gland

  • predominately mucous acini
    • do not stain well ==> white patches
  • ducts are surrounded by attending connective tissue

8

Histologic characteristics of mixed acini

  • occur @ both submandibular and sublingual glands
  • serous cells surround basal domains ==> form crescent shape profiles = "demilunes"

9

Histologic characteristics of the parotid gland

  • predominantly serous acini
  • large excretory ducts are surrounded by connective tissue
  • SA = serous acini
  • Ad = adipose cells

10

Histologic characteristics of serous ducts

  • intercalated duct

11

Histological characteristics of mucous ducts

12

Identify

  • duct from serous acini

13

Location? Identify A & B

  • location = sublingual gland
  • A = larger duct
  • B = mucous acini

14

Identify

  • duct from mucous acinus

15

Identify 1 - 7

1. lumen of acinus

2. mucous secretory granules

3. nucleus of mucous cell

4. cells of serous demilunes

7. periacinar connective tissue

16

Location? Identify A, B, C

  • location = parotid gland
  • A = adipose
  • B = serous acini
  • C = larger duct

17

Location? Identify A, B

  • location = submandibular gland
  • A = serous acini
  • B = mucous acini

18

Major layers of GI tract (general): esophagus ==> anus

  • closest ==> farthest from lumen:
  • mucosa
  • submucosa
  • muscularis externa
  • serosa or adventitia

19

Structure of esophagus

  • 1 = lumen
  • 2= mucosa
  • 3 = epithelium
  • 4 = lamina propria
  • 5 = muscularis mucosa
  • 6 = submucosa
  • 7 = muscularis externa, inner circular
    • some striated muscle in upper 1/3 - 2/3 of esophagus
  • 8 = muscularis externa, outer longitudinal
  • 9 = adventitia. 

20

Histologic characteristics of esophageal wall

  • closest ==> farthest from lumen:
  • epithelium = squamous cells (black line)
    • contains distinct regious of differentiation
  • lamina propria (LP) = loose connective
    • capillaries/small BVs
    • lymphocytes
    • lymphatic vessels (LY)
  • muscularis mucosa (yellow line)
    • contains smooth muscle

21

Histologic characteristics of esophogeal-gastric junction

  • abrupt epithelial change
  • thickening of muscularis mucosa

22

Layers of the stomach

  • rugae = large folds
  • serosa = continous w/peritoneum
  • muscularis externa has three layers
    • inner oblique
    • middle circular 
    • outer longitudinal

23

Histologic characteristics of gastric wall

  • simple columnar epithelium (mucous-secreting, E)
  • lamina propria (LP)
  • gastric pits (GP)
  • gastric glands (GG)
  • lymph nodule (LN)
  • parietal cells (PC)
  • groups of chief or peptic cells (CC) at the base of the gastric glands (encircled) next to the muscularis mucosa (MM) 

24

Location? Identify A-J

  • A = simple columnar epithelium/mucosa
  • B = gastric pits
  • C = lamina propria
  • D = gastric glands
  • E = lamina propria
  • F = parietal cells
  • G = lamina propria
  • H = lymph nodule
  • I = muscularis mucosa
  • J = chief (peptic) cells

25

Location? Identify A, B

  • location = stomach
  • A = rugae
  • B = lymph node

26

Identify A - I

  • A = surface epithelium
  • B = gastric pits
  • C = lyphoid nodule
  • D = gastric glands
  • E = lamina propria mucosae
  • F = submucosa
  • G = muscularis mucosae
  • H = smooth muscle layer
  • I = serosa

27

Identify A, B, C

  • A = esophagus
  • B = esophageal-gastric jxn
  • C = stomach

28

Location? Identify A - E

  • location = esophagus
  • A = mucosal layer/squamous epithelium 
  • B = muscularis mucosae
  • C - E = lamina propria
  • F = lymphatic vessel

29

Identify 1-9

1 = lumen
2= mucosa
3 = epithelium
4 = lamina propria
5 = muscularis mucosa
6 = submucosa
7 = muscularis externa, inner circular

8 = muscularis externa, outer longitudinal
9 = adventitia. 

30

Identify A-D

  • A = surface mucous cells
  • B = mucous neck cells
  • C = parietal cells
  • D = chief cells

31

Identify regions 1-3 & structures A-E

  • 1 = gastric pit
  • 2 = neck
  • 3 = base
  • A = parietal cells
  • B = chief cells
  • C = mucous neck cells
  • D = parietal cells
  • E = surface mucous cells

32

Location? Fxn?

  • location = stomach; gastric pits
  • fxn = mucous secreting cell

33

Location? Fxn?

  • stomach; @ neck of gastric gland
  • A = parietal cells
  • fxn = secrete HCl

34

  • Location?
  • Identify A, B
  • A fxn?

  • stomach; base of gastric gland
  • A = chief cells
  • B = muscularis mucosae
  • A fxn = secrete pepsinogen

35

Identify. Fxn?

  • chief cell
  • fxn = secrete pepsinogen

36

Identify. Fxn?

  • parietal cell
  • fxn = secrete HCl

37

Characteristics of blood supply to stomach

  • arterial supply ==> mucosa originates from arterioles @ submucosa
    • ==> capillary networks at LP and surface epithelium

38

Identify.

Junction between pylorus (stomach) and duodenum

39

Identify A, B, C

  • A = stomach
  • B = pyloric sphincter
  • C = duodenum

40

Identify A - E + fxns

  • A = plicae circulares
    • fxn = increase SA
  • B = mucosa
    • fxn = protective layer
  • C = submucosa
  • D = villi
    • fxn = increase SA
  • E = brunner's gland
    • fxn = produce/secrete mucous and bicarb to neutralize stomach acid

41

Location? Identify + fxn

  • location = small intestine
  • villi
  • fxn = increase SA for absorption

42

Location? Identify A-G

  • Location = duodenum
  • A = villi
  • B = lamina propria
  • C = brunner's glands
  • D = crypts
  • E = circular smooth muscle
  • F = longitudinal smooth muscle
  • G = lacteal

43

Major surface structural difference throughout intestines

  • decreased/structurally different villi as continue distally from duodenum ==> colon

44

Structure of blood circulation to small intestine

45

Structure of lymphatic drainage @ small intestine

  • lacteals ==> blind end or lymphatic nodule

46

Structure of nervous system innervation @ small intestine

  • parasympathetic ganglia
    • plexus of messner [submucosal]
    • myenteric plexus of Auerbach [muscularis]

47

Location? Identify + fxn

  • location = small intestine
  • A = lacteal
    • fxn = transport lymph/fats

48

Location? Identify + fxn

  • location = small intestine
  • Auerbach's plexus
    • fxn = mostly parasympathetic innervation

49

Location? Identify A, B + fxn

  • small intestine
  • A = muscularis mucosae
  • B = meissner's plexus
    • fxn = autonomic innervation; mostly sympathetic

50

Identify A-D + B fxn

  • A = muscularis mucosae
  • B = brunner's glands
    • Fxn = secrete an alkaline (pH 8-9) mucoid product that neutralizes the acidic chyme from the stomach 

  • C = inner circular smooth m.

  • D = outer long smooth m.

51

Identify A,B

  • A = goblets
  • B = digestive/absorptive cells (enterocytes)

52

Location? Identify

  • location = small intestine
  • digestive/absorptive cells (enterocytes) + microvilli

53

Location? Identify + cell types 

  • small intestine
  • crypts of lieberkuhn
    • undifferentiated stem cells
    • endocrine cells
    • panneth cells = eosinophilic granules + defensins (antibacterial peptides) + lysozyme

54

Location? Identify A,B + A fxn

  • Small intestine, @ crypts
  • A = panneth cells
    • fxn = bacterial protection
  • B = muscularis mucosae

55

Location? Identify + fxn

  • location = ileum
  • Peyer's patches = aggregations of lymphatic nodules
    • more abundant and larger @ ileum

56

Mechanism of mucosal immunity

  1. antigens transported to lymphoid tissue by M cells
  2. effector B cells are stimulated and migrate to distant glandular/mucosal tissues
  3. B cells ==> IgA producing plasma cells
  4. IgA abs transported into lumen
  • **entry of antigens at one location in the GI tract can provide the entire GI tract with immune protection 

57

Characteristics of M Cells

  • localized by lymphoid tissue e.g. peyer's patches
  • continously endocytose material ==> intraepithelial pockets filled w/lymphocytes

58

Mechanism of IgA transport @ gut (general)

  1. synthesis @ RER ==>
  2. golgi ==>
  3. basolateral PM ==>
  4. binds receptor @ basolateral PM of enterocytes ==>
  5. vesicular formation and transcytosis ==> 
  6. vesicle fuses w/apical PM
  • the pIgA-R does not recycle like most receptors==> metabolic expense to transport polymeric IgA molecules into the lumen of the gut

59

IgA transport @ salivary glands/hepatocytes

  • Salivary gland acinar cells and hepatocytes also transport polymeric IgA
  • salivary: secreted from the glands directly into the mouth
  • hepatocytes: liver into bile and thence into the duodenum

60

Identify A,B, C

  • A = lumen w/feces
  • B = crypts of lieberkuhn
  • C = lymph nodules

61

Location? Indentify A + composition

  • location = colon
  • A = crypts of lieberkuhn
    • abundant @ colon
    • contains mostly goblet cells
    • some endocrine cells

62

Location?

appendix ("cecum")

63

Location? identify

  • location = colon
  • muscularis externus 

64

Identify A,B

  • A = rectum
  • B = anal canal
  • anal-rectal jxn ==> abrupt change from columnar to stratified squamous epithelium