Stomach made up of 3 parts1. cardia
2. fundus
3. bodyCardia (stomach)within 3 cm of the GE junction
abundant mucus glandsFundus of the stomachsuperior to the GE junction
in contact with the diaphragmBody of the stomachlargest region
glands secrete most of the acid and enzymes3 layers of muscles of the stomachoriented in different directions to help turn contents and aid in digestion
1. longitudinal
2. circular
3. oblique: above mucosal surfaceRugaefolds that allow extensibility of stomach; gastric gases secretionpylorus*food stays here for ~2hrs*
gastric outlet
antrum and canal
pyloric sphinctor: controls outflow from stomach, gives out small amounts at a timecongenital pyloric stenosischildren with thickened muscles can block with ulcersThings that erode mucus glands of the stomach1. drugs (aspirin)
2. alcoholGastric Mucosasecretes about 1500mL of fluid a day (1.5L)
parietal cells
gastric pH maintained between 1.5-2.0
chief cells
littla absorption by mucosa
alcohol can be absorbedparietal cellsproximal portion of each gastric gland
secrete intrinsic factor - needed for vitamin B12 absorption
secrete HClGastric pH maintained between 1.5-2.0-kills most microorganisms
-denatures proteins and inactivates most enzymes in food
-helps breakdown plant cell walls and CT in meatchief cellsabundant at the base of the gland
secrete pepsinogen for protein digestionlittle absorption by the mucosa-epithelial cells covered by an alkaline blanket
-gastic lining somewhat impermeable to wateralcohol can be absorbed in the stomachabsorbed before food consumed with it!
absorption is SLOWED by fatty foodsDuodenum-25cm segment of the small intestine closest to the stomach
-mixes chyme (food and gastric secretions_ from the stomach with secretions from the liver and pancreas
-retroperiteneal except for the very proximal portionDuodenal glands protect the muscosa fromacidic chyme
-stimulated by local reflexes, arrival of chyme and vagal stimulation
inhibited by sympathetic stimulation
(may explain some duodenal