Stomach Flashcards
What region of the stomach is surrounded by smooth muscle and contains mostly mucus-secreting glands?
cardia
What region of the stomach is glandular and secretes acid, pepsin, and some mucus?
fundus
What region of the stomach is the largest, main part where food is mixed and starts to break down?
body
What region of the stomach contains 1’ mucus and gastrin secreting glands?
pylorus
What does the combination of food breakdown via musuclar activity and chemical breakdown via gastric secretion make?
chyme
What is the third layer of muscle in the stomach?
inner oblique layer in the muscularis externa
How much absorption occurs in the stomach?
a little bit (some water, some drugs, and alcohol)
What are the prominent longitudianl folds on the lining of the stomach?
rugae
What type of epithelium is the stomach lines by?
simple columnar epithelium
What is the order of glands from superficial (lumen) to deep (in the wall)
mucous
isthmus
neck
deep (can extend into muscularis mucosae)
What are gastric pits?
glandular body of stomach; mucosa is prominent
What do gastric glands contain?
HCl and pepsinogen
gastrin and lipase
pepsinogen is converted to pepsin by…
HCl
What protects the mucosa layer of the stomach from acid?
a thick layer of mucus
What are the five types of extra cells in the gastric epithelium?
acid producing parietal cells
enzyme-producing chief cells
mucus-secreting cells
stem cells
enteroendocrine cells
What are the three secretions of the gastric epithelium?
hydrochloric acid
proteolytic enzyme (pepsin)
mucus
What cell type covers luminal surface and upper 1/3 of the pit?
mucus secreting cells
What do mucus secreting cells secrete?
thick, insoluble mucus and bicarbonate ions
What do the mucus neck cells look like?
- smaller and less regular in shape that surface
- basal nucleus
- small mucin vacuoles
What do the mucus surface cells look like?
- tall columnar
- basal nuclei
- clear cytoplasm
What gastric glands secrete soluble mucus and is located in the upper 1/3 of the pit and at the neck of the gland?
mucus neck cells
What cells secrete HCl?
parietal cells
What are the characteristics of parietal cells?
- secrete HCl
- pyramidal
- central nucleus
- pale, eosinophilic cytoplasm
- deep microvilli
- produce intrinsic factor
What cells produce intrinsic factor which is necessary for absorption of vitamin B12?
parietal cells
What is necessary for absorption of vitamin B12?
intrisic factor
What are the characteristics of chief cells?
- large, basophilic nuclei
- eosinophilic cytoplasm
- granules contain pepsinogen
What do parietal cells secrete?
HCl and intrinsic factor
What gastric glands are located at the base?
chief cells
What do chief cells secrete?
inactive pepsinogen
What are parietal and chief cells controlled by?
- autonomic nervous system
- hormones from endocrine cells in region of pylorus
What stimulates secretion of HCl and pepsin?
gastrin
What secretes gastrin?
G cells
What inhibits secretion of gastrin?
somatostatin
What inhibits gastric secretion and stimulates smooth muscle contraction?
secretin
What are the characteristics of gastric endocrine cells?
- small and round
- base of glands
- secrete gastrin and serotonin
Where are most undifferentiated stem cells?
neck of gland
What causes gastritis?
irritation of stomach due to…
- excessive alcohol use
- chronic vomiting
- stress
- medications
- H. pyloir (too much)
- bile reflux
- infections (bacteria
What are stomach ulcers frequently associated with?
chronic infection with Helicobacter pylori
What are gastric ulcers?
painful sores either in the stomach or small intestine
