paracrines (2)
somatostatin
histamine
hormones (5)
gastrin CCK secretin GIP motilin
neurocrines (5)
ACh norepinephrine VIP GRP Substance P
VIP functions (4)
relaxation of smooth muscle
increased pancreatic H2O & HCO3 secretion
increased intestinal secretions
inhibits gastrin-stimulated H+ secretion
Bombesin/GRP function
mediates vagally-stimulated gastrin release from gastric G cells
what mediates relaxation of the lower esophageal sphincter
VIP
norepinephrine functions (3)
increased salivary secretions
contraction of sphincters
relaxation of smooth muscle
location of myenteric plexus
between the longitudinal & circular muscle layers
location of submucosal plexus
in the submucosal layer
sympathetic innervation of the salivary glands?
cervical ganglia
sympathetic innervation to the stomach?
celiac ganglia
ACh functions (3)
increased gastric secretions
relaxation of sphincters
contraction of smooth muscle
enkephalins functions (2)
contraction of smooth muscle
decreased intestinal secretion
neuropeptide Y functions (2)
relaxation of smooth muscle
decreases intestinal secretion
Substance P functions (2)
contraction of smooth muscle
increased salivary secretion
oral phase?
initiation of the swallowing reflex
pharyngeal phase?
breathing is inhibited
esophageal phase?
propels food through the esophagus
omeprazole inhibits?
H+/K+ pump
stimulator of primary peristalsis?
medullary swallowing center
gastric secretions use?
H+/K+ pump
mechanisms of gastric secretion in the parietal cell (4)
stimulation of CCK receptors by gastrin
stimulation of muscarinic receptors by ACh
H2 receptors by gastrin-induced histamine
H2 receptors by ACh-induced histamine
pepsinogen secreted by?
chief cells
mucous neck cells secrete?
mucus & pepsinogen
factors that increase gastric emptying (3)
PNS stimulation
Gastric distension
Gastrin & motilin
factors that decrease gastric emptying (3)
SNS stimulation
Secretin, CCK, GIP
Enterogastric reflex (food digestion products present in duodenum)
cephalic phase stimulator
PNS
gastric phase stimulators (2)
distension
peptides, amino acids
increases gastric mixing & emptying (4)
PNS stimulation
gastric distension
gastrin & motilin
increases gastric emptying during migrating myoelectrical complexes (2)
gastrin
motilin
decreases gastric emptying & mixing (6)
SNS secretin CCK GIP H+ digestion products of fats & proteins
pancreatic juice at low flow rates?
bicarbonate is lowest
chloride is highest
as flow rate increases, pancreatic juice:
concentration of bicarb increases
regardless of flow rate, pancreatic juice is (2)
isotonic
Na+ & K+ are always similar to plasma
mediator of pancreatic cephalic phase
PNS
stimulatory phase
mediator of gastric phase of pancreatic secretion
gastric distension (vasovagal reflex) stimulatory phase
fats & protein products in the duodenum stimulate?
CCK from I cells
increased pancreatic enzyme secretion
H+ in the duodenum stimulates?
secretin from S cells
increased aqueous component of pancreatic juice
CCK effects of the gallbladder (2) & stimulation?
contraction of the gallbladder
relaxation of sphincter of Oddi
CCK is stimulated by ingestion of a fat-rich meal
increases intestinal motility (5)
ACh motilin CCK Substance P Enkephalins
decreases intestinal motility (5)
Norepi Somatostatin Secretin GIP VIP
CCK functions in pancreas, liver, & gallbladder (4)
gallbladder contraction
increased pancreatic enzyme secretion
relaxation of sphincter of Oddi
potentiates secretin-induced stimulation of pancreatic HCO3 secretion
secretin functions on gallbladder, liver, and pancreas (3)
increased pancreatic HCO3 secretion
increased HCO3 & H2O secretion by the liver
increased bile production
enterogastric reflex
decreases gastric emptying when food digestion products are present in the duodenum
gastroileal reflex
gastric secretion or motility will increase ileal motility
ileocecal reflex
distension of the ileum relaxes ileocecal sphincter
gastrocolic reflex
distension of the stomach (after a meal) increases colonic motility
results in the urge to defecate
defecation reflex
distention of the rectum causes a reflex relaxation of the internal anal sphincter
absorption of glucose & galactose (method & channel)
Na+-dependent secondary active transport
SGLT1
fructose absorption
facilitated diffusion
glucose, galactose, & fructose transport across basolateral membrane
facilitated diffusion via GLUT2
amino acid absorption (where & how)
in the small intestine
co-transport with sodium
amino acid transport across basolateral membrane
facilitated diffusion
dipeptide & tripeptide absorption & transport across basolateral membrane
co-transport w/ hydrogen
passively diffuse across basolateral membrane
fatty acid absorption
passive diffusion
pancreatic lipase reaction
TGs –> 2-monoglyceride & fatty acid
cholesterolester hydrolase products
cholesterol
fatty acid
glycerol
phospholipase A2 products
lycolecithin
fatty acid
