GASTRITIS Flashcards
what is the stomach?
J shaped muscle organ located in the left upper abdominal cavity inferior to the diaphragm
what is the pathophys of what the stomach does?
contributes to mechanical and chemical digestion of food from the esophagus before releasing it, as CHYME, to the small intestine
what is the greater curvature of the stomach?
convex lateral surface of stomach
what is the lesser curvature of the stomach?
concave medial surface of the stomach
what is the stomach held in place by?
greater omentum
lesser omentum
where is the greater omentum?
runs from the greater curvature to the posterior abdominal wall
where is the lesser omentum?
extends from liver to lesser curvature
what are the 4 regions of the stomach?
- cardia
- fundus
- body
- pylorus
what is the cardia of the stomach?
region where food passes from the esophagus and into the stomach
what is the fundus of the stomach?
dome-shaped region located above and to the left of the cardia
stores undigested food and gases
what is the body of the stomach?
largest region of the stomach
what is the pylorus of the stomach?
funnel shaped region that connects to the duodenum
what is the pyloric antrum ?
wider end of pylorus
what is the pyloric canal?
narrow end of pylorus
what is the pyloric sphincter?
smooth muscle that controls gastric emptying
what are the 3 physiology aspects about the mucosa of the stomach
- forms large folds when stomach is empty known as rugae
- contains a protective alkaline mucus
- gastric pits are depressions that mark entry to gastric glands
what is the in the submucosa of the stomach?
contains blood vessels, lymphatic vessels and nerves
what is the muscularis externa responsible for?
responsible for mechanically breaking down food into smaller particles
what are the layers of the muscularis externa?
inner oblique layer
middle circular layer
outer longitudinal layer
what do chief cells do?
secrete pepsinogen, the inactive proenzyme of pepsin
what 2 things to the parietal cells produce?
- HCl
- intrinsic factor
what is entailed in the HCl production of parietal cells?
-high acidity (pH 1.5-3.5) of stomach
> kill ingested bacteria
> denatures proteins
- activates digestive enzyme, pepsin
what is intrinsic factor? (produced by parietal cells)
glycoprotein necessary for the absorption of vitamin B12 in the small intestine
-WHY IS B12 VITAL TO SURVIVE?
its a cofactor in heme production -> Hgb
what do mucous neck cells secrete?
alkaline mucus
what are the 2 types of enteroendocrine cells?
D cells and G cells
what do D cells secrete?
somatostatin - inhibitory
what do G cells secrete?
they secrete gastrin that then stimulates parietal cells
what do gastric enzymes have the potential to do?
digest themselves
what are the 3 things that protect the stomach from self-digestion?
- mucosal barrier
- tight junctions
- stem cells
what is the mucosal barrier?
thick coating of bicarbonate-rich mucus that acts as a physical barrier. the bicarb ions neutralize the acid.
what are tight junctions?
they block gastric juice from penetrating underlying tissues
where are stem cells located?
they are located at the junction of gactric pits and gastric glands
what do stem cells do?
they replace damaged epithelial mucosal cells
when it eh surface epithelium of the stomach replaced?
it is completely replaced every 3-6 days