Digestive Flashcards
Enteric Nervous System
nervous system of the gut
Gastric pits vs. rugae
- Gastric pits=microscopic, only includes mucosa
- Rugae=much larger, can be seen with the naked eye, includes all layers of stomach (mucosa, submucosa, muscularis, serosa)
Muscular layers of stomach (order from outer to inner)
outer longitudinal
middle circular
inner oblique
Serosa vs. Adventitia
- Serosa=there is a peritoneum
- Adventitia=no peritoneum (ex: esophagus)
Parts of stomach
Cardia (near esophagus)
Fundus
Body
Pylorus
Parts of pylorus region
Antrum-waiting room
Canal
Duodenum
- absorptive cells, goblet cells, granular cells, endocrine cells
- microvilli and many folds
- contains bile (important for fat digestion) and pancreatic ducts
Jejunum
absorbs nutrients
Villi vs microvilli
- Villi: much larger than microvilli, composed of many cells
- Microvilli: projection off of ONE cell (can have lots of microvilli on the same cell), increase surface area for absorption
Peyer’s patches
small patches of lymphatic tissue (immune cells) found throughout the ileum
Taenia coli
longitudinal ribbons of smooth muscle on the outside of the ascending, transverse, descending and sigmoid colons
Anal canal
- takes food 18-24hrs to pass through
- feces is product of water, indigestible food and microbes
- MICROBES SYNTHESIZE VITAMIN K (this vit. K is absorbed by the colon)
Porta
gate where blood vessels, ducts, nerves enter and exit (liver)
Lobes of liver
right (largest), left, caudate, quadrate
Lobule
- basic structure of liver
- hexagon shaped
- each has portal triad (hepatic duct, hepatic artery, hepatic portal vein)
- filters blood
Hepatic sinusoid
-where blood from hepatic artery and hepatic portal vein mix
(hepatic artery blood is oxygenated, hepatic portal vein blood is from the intestines so it is deoxygenated but very nutrient rich)
-has phagocytic cells which filter blood
Hepatocytes
- help detox
- arranged in sheets (called hepatic cord) going up and down liver lobule
Hepatic duct
transport bile out of liver
Common hepatic duct
formed by joining of left and right hepatic ducts
Cystic duct
- joins common hepatic duct
- comes from gallbladder
Common bile duct
formed from common hepatic duct and cystic duct
Pancreas
Both endocrine and exocrine
- Endocrine tissue has pancreatic islets (Islets of Langerhan) that produce insulin and glucagon
- Exocrine tissue produces digestive enzymes (acinar cells)
Cells of stomach
- Parietal cells=secrete HCl
- Chief cells=secrete pepsinogen (becomes pepsin when it comes in contact with HCl)
- Goblet cells=secrete mucous
- Enteroendocrine/ G cells=secrete gastrin
