SM_132b: Histology of the Gi System Flashcards
Digestive system includes ___ and ___ organs
Digestive system includes hollow and solid organs
- Hollow (foot transits): esophagus, stomach, small intestine, large intestine, rectum, and anal canal
- Solid (produce enzymes and bile which aid in digestion): pancreas and liver (and gall bladder(
Four layers of hollow organs of the digestive system are ____, ____, ____, and ____
Four layers of hollow organs of the digestive system are mucosa, submucosa, musculari propia/externa, serosa/adventitia
- Mucosa: epithelium, lamina propria / muscularis mucosa
Esophagus is composed of ____, ____, ____, and ____
Esophagus is composed of mucosa, submucosal glands, muscularis propria / externa, and adventitia
Esophagus is lined by ___
Esophagus is lined by stratified squamous epithelium
(non-keratinized)
This is the ___
This is the esophagus
In the middle esophagus, there is a transition from ____ to ____
In the middle esophagus, there is a transition from striated muscle to smooth muscle
Stomach regions include ____, ____, ____, and ____
Stomach regions include cardia, fundus, corpus (body), and pylorus
This is the ____
This is the stomach
This is the ____
This is the gastric mucosa
Describr the histology of the main stomach anatomical regions
Histology of the main stomach anatomical regions
____ contains cytoplasmic mucus globules in multiple small vacuoles
Gastric surface epithelium contains cytoplasmic mucus globules in multiple small vacuoles
Describe histology of the deep/glandular epithelium
Histology of the deep/glandular epithelium
- Cardia: mucus-secreting glands only
- Fundus (oxyntic mucosa): parietal cells make acid and intrinsic factor, chief cells produce pepsinogen and lipase, and endocrine cells produce hormones
- Antrum/pylorus: mucus-secreting glands and endocrine cells (gastrin-producing cells: G cells)
This is the _____
This is the cardia and antrum of the stomach
This is the ____
This is the antrum of the stomach
This is the ____
This is the fundus/body of the stomach
Small intestine is involved in ___ and ___
Small intestine is involved in digestion and absorption
- Secretes enzymes and has mucous producing glsands
- Highly-folded mucosa
- Liver and pancreas secrete their exocrine secretion into duodenum
Small intestines have ____, ____, ____, and ____ to maximize absorption
Small intestines have plicae circularis, villi, enterocytes, and microvilli
- Plicae circularis: circumferential folds involving submucosa
- Villi: fingerlike projections of mucosa
- Enterocytes: simple columnar epithelial cells specialized for absorption
- Microvilli: fingerlike protrusions of enterocytes on apical plasma membrane
These are ____ and ____ of ____
These are plica circulares and villi of small intestine
___ are intestinal glands
Crypts of Lieberkuhn are intestinal glands
Ileum of small intestine empties into the ____
Ileum of small intestine empties into the cecum of the large intestine
____ glands are found in the duodenum
Brunner glands are found in the duodenum
In the duodenum, villi are lined by ___ and ___
In the duodenum, villi are lined by enterocytes and goblet cells
____ are characteristic of the ileum
Peyer’s patches (lymphoid follicles) are characteristic of the ileum
Jejunum is characterized by the absence of ____ and ____
Jejunum is characterized by the absence of Brunner’s glands and Peyer’s patches
Jejunum histology includes ____ and ____
Jejunum histology includes tall villi and villous:crypt of 1:3 or 1:5
___ are located in the bases of the crypts of the jejunum and their antibacterial actions regulate gut flora
Paneth cells are located in the bases of the crypts of the jejunum and their antibacterial actions regulate gut flora
Three layers of small bowel mucosa are ____, ____, and ____
Three layers of small bowel mucosa are
- Simple columnar epithelium of enterocytes and goblet cells
- Lamina propria: inflammatory cells and loose connective tissue
- Muscularis mucosae: smooth muscle
Submucosa consists of ____ with submucosal glands
Submucosa consists of loose to dense connective tissue with submucosal glands
- Submucosa extends into plical folds
- Meissner’s plexus: parasympathetics for glandular secretion
Muscularis externa and serosa contains ___ with inner circular and outer longitudinal layers
Muscularis externa and serosa contains smooth muscle with inner circular and outer longitudinal layers
- Auerbach’s plexus: parasympathetics for muscle contraction (peristalsis)
Colon consists of ____, ____, ____, ____, and ____
Colon consists of cecum, ascending colon, transverse colon, descending colon, and sigmoid colon
Large intestine has no ___, abundant ___, and ___
Large intestine has no villi, abundant goblet cells, and teniae coli (3 longitudinal bands)
Colonic mucosa consists of ____, ____, and ____
Colonic mucosa consists of epithelium, lamina propria, and muscularis mucosae
- Epithelium: scattered goblet cells, deep crypts, and no villi
- Lamina propria: inflammatory cells
- Muscularis mucosae
Muscularis externa of colon contains ____ with inner circular and outer longitudinal layers
Muscularis externa of colon contains smooth muscle with inner circular and outer longitudinal layers
- Auerbach’s plexus: parasympathetics for muscle contraction (peristalsis)
Epithelium of colon formed of ____ with many ____, ____, and ____ and less ____
Epithelium of colon formed of columnar absorptive cells with many goblet cells, endocrine cells, and basal stem cells and less Paneth cells (only proximal colon)
Colonic mucosa has deep crypts but there are no villi
Blood enters the liver via the ____ and ____ and leaves via the ____ emptying into the ____
Blood enters the liver via the hepatic artery and portal vein and leaves via the hepatic veins emptying into the IVC
- Bile and blood flow in opposite directions
Basic liver organizational element is the ____
Basic liver organizational element is the liver lobule
This is the ___
This is the liver
This is the ___
This is the liver
This is the ____
This is the liver
Blood flow in the sinusoids is from the ____ to the ____
Blood flow in the sinusoids is from the portal triad to the central vein
Zone ___ of the liver has the highest oxygenation, while zone ___ has the lowest oxygenation
Zone 1 of the liver has the highest oxygenation (closer to the hepatic arteries), while zone 3 has the lowest oxygenation (closest to the central vein)
Dilute bile exits the ___ and is stored and concentrated in the ___
Dilute bile exits the liver and is stored and concentrated in the gall bladder
(40-fold)
Gallbladder and biliary tree (common bile duct) are lined by ____
Gallbladder and biliary tree (common bile duct) are lined by simple columnar epithelium
Gallbladder has ____ sinuses
Gallbladder has Rokitansky-Aschoff sinuses
Pancreas touches the ____
Pancreas touches the duodenum
Exocrine pancreas is composes of ____ and ____
Exocrine pancreas is composes of acini and ducts
- Ducts secrete bicarbonate to neutralize chyme from the stomach entering the duodenum
This is an ___ of the pancreas
This is an acinus of the pancreas
- Pancreas breaks down most dietary components via proteases, lipases, amylases, and nucleases
Pancreatic endocrine cells are clustered in ___
Pancreatic endocrine cells are clustered in Islets of Langerhans
- Secrete insulin, glucagon, and somatostatin
Endocrine cells in pancreas are ____, ____, and ____
Endocrine cells in pancreas are
- Beta (B) cells: secrete insulin -> uptake of glucose from the bloodstream and its utilization and storage
- Alpha (A) cells: secrete glucagon (reciprocal effects of insulin) -> increases circulating glucose and gluconeogenesis, mobilizes fat
- Delta (D) cells: secrete somatostatin, inhibits A and B cell secretion and exocrine pancreas secretion
