Histology of the Gastrointestinal System Flashcards

1
Q

Layer of the gastrointestinal tract in which MOST esophageal, gastric, and intestinal glands are seen

A

Lamina propria

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2
Q

SUBMUCOSAL glands of the esophagus and duodenum

A

Esophagus - deep esophageal gland

Duodenum - Brunner gland (or duodenal gland)

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3
Q

Metaplasia of the normal stratified squamous epithelium of the esophagus into a simple columnar epithelium due to extensive, chronic gastroesophageal reflux; HIGH RISK for adenocarcinoma

A

Barret esophagus

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4
Q

Cells found at the base of the crypt of Lieberkuhn:

  • gastrointestinal epithelial cells that synthesize and secrete substantial quantities of antimicrobial peptides and proteins
  • sense bacteria via the MyD88-dependent toll-like receptor (TLR) activation which then triggers antimicrobial action
A

Paneth cells

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5
Q

Another name for the intestinal gland - cells villi-covered by epithelium which houses the following cells; found along the lamina propria:

  • ENTEROCYTE (water & electrolyte absorption)
  • GOBLET CELL (mucin secretion)
  • ENTEROENDOCRINE or ARGENTAFFIN CELL (hormone secretion)
  • CUP CELL (unknown function, unique to mammals)
  • TUFT or BRUSH CELLS (chemosensation)
  • PANETH CELLS (anti-microbial peptides secretion)
  • STEM CELLS (tissue regeneration)
A

Crypt of Lieberkuhn (or Lieberkuhn gland, or intestinal crypt)

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6
Q

Cells found at the base of the crypt of Lieberkuhn:

  • undifferentiated multipotent cells of the GIT
  • responsible for tissue regeneration
A

Stem cells

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7
Q

Cells found at the crypt of Lieberkuhn:

  • also found along the gastrointestinal epithelium
  • principally responsible for water & electrolyte absorption
A

Enterocyte

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8
Q

Cells found at the crypt of Lieberkuhn:

  • also found along the gastrointestinal epithelium
  • secretes gel-forming mucin, the major component of the mucus lining of the GIT
A

Goblet cells

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9
Q

Cells found at the crypt of Lieberkuhn:

  • characteristically stain to the silver stain
  • encompasses a variety of cell types responsible for the synthesis and secretion of various hormones for GIT motility and secretion
A

Enteroendocrine cells (or argentaffin cells)

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10
Q

Cells found at the crypt of Lieberkuhn:

  • of unknown significance/function
  • unique to the GIT lining of mammals
A

Cup cells

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11
Q

Cells found at the crypt of Lieberkuhn:

  • also fund in the respiratory tract
  • act as chemosensory receptors
A

Tuft cells (or brush cells)

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12
Q

Specific type of enteroendocrine/argentaffin cell:

  • neuroendocrine cells found in the lamina propria of the GIT; reside alongside the epithelium lining of the lumen of the digestive tract
  • play a crucial role in gastrointestinal regulation, particularly intestinal motility and secretion
  • modulate neuron signalling in the enteric nervous system (ENS) via the secretion of the neurotransmitter SEROTONIN (for persistalsis, gland secretion, etc.) and other peptides (HISTAMINE)
A

Enterochromaffin (EC) cell, or Kulchitsky cell

as opposed to the PNEC, the pulmonary neuroendocrine cells, or the Kulchitsky cells of the respiratory tract

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13
Q

Specific type of enteroendocrine/argentaffin cell:

  • secretes the incretin known as GASTRIC INHIBITORY PEPTIDE (GIP)
  • promotes triglyceride storage
A

K cell

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14
Q

Specific type of enteroendocrine/argentaffin cell:

  • primarily found in the ILEUM and LARGE INTESTINE, but also in the duodenum and jejenum
  • secretes the incretin known as GLUCAGON-LIKE PEPTIDE-1 (GLP-1)
  • also secretes PANCREATIC PEPTIDE YY, OXYNTOMODULIN, and GLP-2
A

L cell

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15
Q

Specific type of enteroendocrine/argentaffin cell:

  • found in the DUODENUM and JEJENUM
  • secretes CHOLECYSTOKININ (CCK)
  • modulates bile secretion, exocrine pancreas secretion, and satiety
A

I cell

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16
Q

Specific type of enteroendocrine/argentaffin cell:

  • found in the PYLORUS/ANTRUM
  • secretes GASTRIN
  • stimulates gastric acid secretion
A

G cell

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17
Q

Specific type of enteroendocrine/argentaffin cell:

  • found in the JEJENUM
  • secretes NEUROTENSIN
  • controls smooth muscle contraction
A

N cell

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18
Q

Specific type of enteroendocrine/argentaffin cell:

  • found in the DUODENUM and JEJENUM
  • secretes SECRETIN
  • stimulates exocrine pancreatic secretion
A

S cell

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19
Q

Specific type of enteroendocrine/argentaffin cell:

  • found in the PYLORUS and DUODENUM
  • secretes SOMATOSTATIN (also known as growth hormone-inhibiting hormone or GHIH)
  • inhibits the secretion of other hormones
A

Delta cell (or D cell)

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20
Q

Specific type of enteroendocrine/argentaffin cell:

  • found in the SMALL INTESTINE
  • secretes MOTILIN
  • modulates intestinal motility
A

M cell

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21
Q

Another name for the stomach gland - houses the following cells:

  • MUCUS NECK CELLS (mucus secretion)
  • CHIEF or ZYMOGENIC CELLS (pepsinogen secretion)
  • PARIETAL or OXYNTIC CELLS (hydrochloric acid and intrinsic factor)
  • ENTEROENDOCRINE CELLS (hormonal/serotonin secretion)
A

Gastric pit (or gastric gland)

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22
Q

Gastric pit cell responsible for mucus secretion

A

Mucus neck cell

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23
Q

Gastric pit cell responsible for pepsinogen secretion

A

Chief cell (or zymogenic cell)

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24
Q

Gastric pit cell responsible for HCL and intrinsic factor (IF) secretion

A

Parietal cell (or oxyntic cell)

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25
Q

Group of gastric pit cells responsible for hormonal secretion

A

Enteroendocrine cells (or argentaffin cells)

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26
Q

Mucus-secreting cells that internally line the stomach, also initially lining the gastric pits but eventually making way to other cell types as the lining approaches the pits internally (towards the pit base)

A

Foveolar cells (or surface mucous cells)

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27
Q

Structural specialization found in the small intestine, described as permanent transverse, circularly-arranged folds that contain a core of submucosa

A
Plica circularis (pl. plicae circulares) or:
- valves of Kerckring
28
Q

One of three separate longitudinal ribbons of smooth muscle on the outside of the ascending, transverse, descending and sigmoid colons

A

Taenia coli (pl. taeniae coli)

29
Q

Structural specialization in the large intestine, described as a pouched fold caused by sacculation (sac formation), which gives the colon its segmented appearance due to the relative shorter length of the taeniae coli that run alongside it

A

Haustrum (pl. haustra)

30
Q

Structural specialization of the intestinal villus, described as a penetration of microvasculature and lymphatics into the lamina propria primarily responsible for the absorption of chylomicrons

A

Lacteal

31
Q

Specialized submucosal gland of the esophagus that secretes mucin (lubrication and protection from gastric acid)

(Note: most GIT glands found in lamina propria)

A

Deep esophageal gland

32
Q

Specialized submucosal gland of the duodenum that secretes mucus-rich alkaline secretion (containing bicarbonate) in order to:

  • protect the duodenum from acidic
  • provide an alkaline condition to enabling absorption
  • lubricate the intestinal walls

Also secretes UROGASTRONE, which inhibits parietal and chief cells of the stomach from secreting acid and their digestive enzymes

A

Brunner gland (or duodenal gland)

33
Q

ENS plexus responsible for the control of GIT SECRETION - located in the SUBMUCOSA

A

Meissner plexus (or the submucosal plexus)

34
Q

ENS plexus responsible for the control of GIT MOVEMENT/MOTILITY - located in the TUNICA MUSCULARIS, between the circular and longitudinal layers

A

Auerbach plexus (or the myenteric plexus)

35
Q

Epithelial lining of the esophagus and anal canal

A

Stratified squamous non-keratinized epithelium

36
Q

Epithelial lining of the stomach

A

Simple columnar epithelium

37
Q

Epithelial lining of the instestines

A

Simple columnar epithelium with goblet cells

38
Q

Lymphoid tissue of the GIT, generally more prominent in the ileum and absent in the duodenum

A

Peyer patches

39
Q

Characteristic space between a hepatocyte and its sinusoid

A

Disse space (or perisinusoidal space)

40
Q

Unit of the liver, described as:

  • HEXAGONAL
  • 6 portal triads with 1 central vein
  • emphasizes ENDOCRINE function
A

Classic liver lobule

41
Q

Unit of the liver, described as:

  • TRIANGULAR
  • single portal triad with 3 central veins
  • emphasizes EXOCRINE function
A

Portal lobule

42
Q

Unit of the liver, described as:

  • DIAMOND
  • 2 portal triads and 2 portal veins
  • empasizes BLOOD FLOW and can be divided into 3 zones
A

Liver acinus

43
Q

Liver acinus zone closest to the portal tract/triad, receiving the most oxygen

A

Zone 1

44
Q

Liver acinus zone at the intermediate distance between the portal tract/triad and the portal vein

A

Zone 2

45
Q

Liver acinus zone farthest from the portal tract/triad and receives the least oxygen - the most susceptible zone to ischemic injury

A

Zone 3

46
Q

Macrophages of the liver, found lining the sinusoids

A

Kupffer cells

(Note:
Lung - dust cell
Blood - monocyte
CT, lymphoid tissue,kidney - macrophage & histiocyte
CNS - microglia
Skin - Langerhans cell
Bone - osteoclast
Liver - Kupffer cell
Placenta - Hofbauer cell)
47
Q

Components of the portal triad/tract

A
  • Hepatic artery
  • Portal vein
  • Bile duct
48
Q

Drains the blood within the sinusoids of the liver

A

Central vein

49
Q

Organelle of the hepatocyte that detoxifies drugs

A

Smooth endoplasmic reticulum

50
Q

Organelle of the hepatocyte responsible for protein assembly

A

Rough endoplasmic reticulum

51
Q

Pseudodiverticula or pockets in the wall of the gallbladder; outpouchings of gallbladder mucosa into the gallbladder muscle layer and subserosal tissue as a result of hyperplasia/herniation of epithelial cells through the fibromuscular layer of the gallbladder wall (adenomyomatosis)

Not considered abnormal, but can be associated with cholecystitis

A

Rockitansky-Aschoff sinuses (or entrapped epithelial crypts)

52
Q

Simple columnar epithelial cell of the gallbladder

A

Cholecystocyte

53
Q

4 layers of the gallbladder

A
  1. MUCOSA - made up of the EPITHELIAL LAYER (innermost, lined by simple columnar cholecystocytes) and the underlying LAMINA PROPRIA (mucosal folds and loose connective tissue); distinctive presence of Rokitansky–Aschoff sinuses that may extend in to the fibromuscular layer
  2. FIBROMUSCULAR LAYER - longitudinal, transversem oblique, interspersed smooth muscular tissue not arranged in separate layers, responsible for contraction in bile expulsion
  3. PERIMUSCULAR LAYER - fibrous tissue layer of connective tissue
  4. TUNICA SEROSA - thick layer, covering the outer surface of the gallbladder; continuous with the peritoneum lining the abdominal cavity; contains blood vessels and lymphatics
54
Q

Part of the exocrine pancreas:

LOBE of secretory cells separated by a thin fibrous barrier, surrounding and secreting into a small intercalated duct

A

Acinus (pl. acini)

55
Q

Part of the exocrine pancreas:

Leads directly from the acinus and into the intralobular duct; THINNEST epithelium of any part of the duct system, classified with a “low” simple cuboidal epithelial lining

A

Intercalated duct or:

  • intercalary duct
  • duct of Boll
56
Q

Part of the exocrine pancreas:

Found IN THE LOBULE leading directly from the intercalated duct to outside the lobule in the interlobular duct

A

Intralobular duct

57
Q

Part of the exocrine pancreas:

Leads out of the lobules from intralobular ducts and into the main pancreatic duct, CONNECTING different lobules

A

Interlobular duct

58
Q

Cell of the exocrine pancreas, found in the acini, secreting digestive enzymes called zymogens

A

Acinar cell

59
Q

Cell of the exocrine pancreas, spindle-shaped, extend sinto the acini and is surrounded by the secretory acinar cells; extends from the terminal end of the intercalated duct

A

Centroacinar cell

60
Q

Simple cuboidal epithelial cell of the exocrine pancreas

A

Intercalated cell

61
Q

Specialized cell that resides in the exocrine pancreas that play a role in pancreatic tissue regeneration/repair, as well as pancreatitis and pancreatic cancer by secreting ECM components

A

Pancreatic stellate cell (PaSC)

62
Q

Regions of endocrine pancreas that consists of 1-2% of the pancreatic volume and about 10-15% of its total circulation

A

Islets of Langerhans (or pancreatic islets)

63
Q

Endocrine/islet cells of the pancreas:

  • secretes GLUCAGON
  • 20% of the islet
A

Alpha cell

64
Q

Endocrine/islet cells of the pancreas:

  • secretes INSULIN and AMYLIN
  • 70% of the islet
A

Beta cell

65
Q

Endocrine/islet cells of the pancreas:

  • secretes SOMATOSTATIN
  • < 10% of the islet
A

Delta cell

66
Q

Endocrine/islet cells of the pancreas:

  • secretes PANCREATIC POLYPEPTIDE
  • < 5% of the islet
A

PP cell (or gamma cell)

67
Q

Endocrine/islet cells of the pancreas:

  • secretes GHRELIN
  • < 1% of the islet
A

Episilon cell