GI Histology Flashcards
1
Q
Types of cells lining the oral cavity
A
- stratified squamous epithelium
- non-keratinized, except @ hard palate
2
Q
Types of salivary glands and location
A
- salivary glands = exocrine glands = secrete products into lumen via duct system
- submanidbular
- sublingual
- parotid
- similar structures but different types secretory units (acini)
3
Q
Cell type & location
A
- stratified squamous epithelium
- oral cavity
4
Q
A
- A = parotid gland
- B = sublingual gland
- C = submandibular
5
Q
Types of acini
A
- 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
Q
Histologic characteristics of submandibular salivary gland
A
- serous and mucous acini; serous predominate
- gland is subdivided by connective tissue septa
- serous-secreting sections = darker
- mucous-secreting sections = lighter
7
Q
Histological characteristics of sublingual gland
A
- predominately mucous acini
- do not stain well ==> white patches
- ducts are surrounded by attending connective tissue
8
Q
Histologic characteristics of mixed acini
A
- occur @ both submandibular and sublingual glands
- serous cells surround basal domains ==> form crescent shape profiles = “demilunes”
9
Q
Histologic characteristics of the parotid gland
A
- predominantly serous acini
- large excretory ducts are surrounded by connective tissue
- SA = serous acini
- Ad = adipose cells
10
Q
Histologic characteristics of serous ducts
A
- intercalated duct
11
Q
Histological characteristics of mucous ducts
A
12
Q
Identify
A
- duct from serous acini
13
Q
Location? Identify A & B
A
- location = sublingual gland
- A = larger duct
- B = mucous acini
14
Q
Identify
A
- duct from mucous acinus
15
Q
Identify 1 - 7
A
- lumen of acinus
- mucous secretory granules
- nucleus of mucous cell
- cells of serous demilunes
- periacinar connective tissue
16
Q
Location? Identify A, B, C
A
- location = parotid gland
- A = adipose
- B = serous acini
- C = larger duct
17
Q
Location? Identify A, B
A
- location = submandibular gland
- A = serous acini
- B = mucous acini
18
Q
Major layers of GI tract (general): esophagus ==> anus
A
- closest ==> farthest from lumen:
- mucosa
- submucosa
- muscularis externa
- serosa or adventitia
19
Q
Structure of esophagus
A
- 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
Q
Histologic characteristics of esophageal wall
A
- 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
Q
Histologic characteristics of esophogeal-gastric junction
A
- abrupt epithelial change
- thickening of muscularis mucosa
22
Q
Layers of the stomach
A
- rugae = large folds
- serosa = continous w/peritoneum
- muscularis externa has three layers
- inner oblique
- middle circular
- outer longitudinal
23
Q
Histologic characteristics of gastric wall
A
- 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
Q
Location? Identify A-J
A
- 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
Q
Location? Identify A, B
A
- location = stomach
- A = rugae
- B = lymph node
26
Q
Identify A - I
A
- 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
Q
Identify A, B, C
A
- A = esophagus
- B = esophageal-gastric jxn
- C = stomach
28
Q
Location? Identify A - E
A
- location = esophagus
- A = mucosal layer/squamous epithelium
- B = muscularis mucosae
- C - E = lamina propria
- F = lymphatic vessel
29
Q
Identify 1-9
A
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
Q
Identify A-D
A
- A = surface mucous cells
- B = mucous neck cells
- C = parietal cells
- D = chief cells
31
Q
Identify regions 1-3 & structures A-E
A
- 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
Q
Location? Fxn?
A
- location = stomach; gastric pits
- fxn = mucous secreting cell
33
Q
Location? Fxn?
A
- stomach; @ neck of gastric gland
- A = parietal cells
- fxn = secrete HCl
34
Q
- Location?
- Identify A, B
- A fxn?
A
- stomach; base of gastric gland
- A = chief cells
- B = muscularis mucosae
- A fxn = secrete pepsinogen
35
Q
Identify. Fxn?
A
- chief cell
- fxn = secrete pepsinogen
36
Q
Identify. Fxn?
A
- parietal cell
- fxn = secrete HCl
37
Q
Characteristics of blood supply to stomach
A
- arterial supply ==> mucosa originates from arterioles @ submucosa
- ==> capillary networks at LP and surface epithelium
38
Q
Identify.
A
Junction between pylorus (stomach) and duodenum
39
Q
Identify A, B, C
A
- A = stomach
- B = pyloric sphincter
- C = duodenum
40
Q
Identify A - E + fxns
A
- 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
Q
Location? Identify + fxn
A
- location = small intestine
- villi
- fxn = increase SA for absorption
42
Q
Location? Identify A-G
A
- Location = duodenum
- A = villi
- B = lamina propria
- C = brunner’s glands
- D = crypts
- E = circular smooth muscle
- F = longitudinal smooth muscle
- G = lacteal
43
Q
Major surface structural difference throughout intestines
A
- decreased/structurally different villi as continue distally from duodenum ==> colon
44
Q
Structure of blood circulation to small intestine
A
45
Q
Structure of lymphatic drainage @ small intestine
A
- lacteals ==> blind end or lymphatic nodule
46
Q
Structure of nervous system innervation @ small intestine
A
- parasympathetic ganglia
- plexus of messner [submucosal]
- myenteric plexus of Auerbach [muscularis]
47
Q
Location? Identify + fxn
A
- location = small intestine
- A = lacteal
- fxn = transport lymph/fats
48
Q
Location? Identify + fxn
A
- location = small intestine
- Auerbach’s plexus
- fxn = mostly parasympathetic innervation
49
Q
Location? Identify A, B + fxn
A
- small intestine
- A = muscularis mucosae
- B = meissner’s plexus
- fxn = autonomic innervation; mostly sympathetic
50
Q
Identify A-D + B fxn
A
- 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
Q
Identify A,B
A
- A = goblets
- B = digestive/absorptive cells (enterocytes)
52
Q
Location? Identify
A
- location = small intestine
- digestive/absorptive cells (enterocytes) + microvilli
53
Q
Location? Identify + cell types
A
- small intestine
- crypts of lieberkuhn
- undifferentiated stem cells
- endocrine cells
- panneth cells = eosinophilic granules + defensins (antibacterial peptides) + lysozyme
54
Q
Location? Identify A,B + A fxn
A
- Small intestine, @ crypts
- A = panneth cells
- fxn = bacterial protection
- B = muscularis mucosae
55
Q
Location? Identify + fxn
A
- location = ileum
- Peyer’s patches = aggregations of lymphatic nodules
- more abundant and larger @ ileum
56
Q
Mechanism of mucosal immunity
A
- antigens transported to lymphoid tissue by M cells
- effector B cells are stimulated and migrate to distant glandular/mucosal tissues
- B cells ==> IgA producing plasma cells
- 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
Q
Characteristics of M Cells
A
- localized by lymphoid tissue e.g. peyer’s patches
- continously endocytose material ==> intraepithelial pockets filled w/lymphocytes
58
Q
Mechanism of IgA transport @ gut (general)
A
- synthesis @ RER ==>
- golgi ==>
- basolateral PM ==>
- binds receptor @ basolateral PM of enterocytes ==>
- vesicular formation and transcytosis ==>
- 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
Q
IgA transport @ salivary glands/hepatocytes
A
- 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
Q
Identify A,B, C
A
- A = lumen w/feces
- B = crypts of lieberkuhn
- C = lymph nodules
61
Q
Location? Indentify A + composition
A
- location = colon
- A = crypts of lieberkuhn
- abundant @ colon
- contains mostly goblet cells
- some endocrine cells
62
Q
Location?
A
appendix (“cecum”)
63
Q
Location? identify
A
- location = colon
- muscularis externus
64
Q
Identify A,B
A
- A = rectum
- B = anal canal
- anal-rectal jxn ==> abrupt change from columnar to stratified squamous epithelium
