Integration of Gastrointestinal Function Flashcards
What are the three types of regulation in the GI tract?
neurocrine
endocrine
paracrine
Name the 5 criteria for GI hormones
- found in gastrointestinal endocrine cells
- present in blood
- released by physiologic stimuli
- infusion of the substance exerts identical effect
- administration of antibody blocks the physiologic event
Name 5 important GI hormones
gastrin CCK secretin somatostatin motilin
What is the classic endocrine effect of gastrin?
gastric acid secretion
pancreatic secretion
What is the classic endocrine effect of CCK?
pancreatic secretion
gallbladder contraction
What is the classic endocrine effect of secretin?
pancreatic and biliary bicarbonate secretion
What is the class endocrine effect of somatostatin?
inhibition of gastrin release, pancreatic secretion, and gallbladder contraction
What is the classic endocrine effect of motilin?
interdigestive motility
Name the 5 criteria for enteric neuropeptides
- found in neurons
- mechanisms for biosynthesis exist
- concentrated in nerve terminals.
- released by depolarizing stimuli
- application of the substance exerts an identical effect
Name 6 enteric neuropeptide families
- tachykinins (ex: substance P)
- secretin (ex: VIP/PHI)
- opioids
- bombesins
- gastrin-CCK
- pancreatic polypeptides
What is the classic role of enteric neuropeptides?
motility and secretion
Name the 4 criteria for paracrine substances
- found in effector cells
- released by physiologic stimuli
- released into extracellular fluid
- receptors found on target cells
Name the 4 paracrine substances
histamine
purines
somatostatin
prostaglandins
What is the classic paracrine effect of prostanoids on the gastric mucosal barrier?
increased mucosal blood flow
increased mucous secretion
increased bicarbonate secretion
increased cell turnover
