enteric nervous system

enteric nervous system

nerves in wall of gut

regulated by para/sympathetic

extrinsic regulation

prep for arrival of food

evacuation of faeces

up or down regulating gut function

intrinsic regulation

motility

water and solute movement

blood flow

acid and mucous production

gut hormones

structure of ens

two networks of interconnected ganglia along length of gut

myenteric plexus and submucous plexus

Peristalsis

contract towards oral end and relax towards anal end to push through gut

parietal cell

secretes acid into gut and driven by enteric nerves

pharmacological methods to decrease acid production

proton pump inhibitors

histamines

protaglandin

octreotide

rare use

scarring in liver

bleeding into gut wall due to pressure

cisapride

reflux increases ach release

omeprazole used now instead

antimuscarinic drugs

decrease gut motility

can be used to treat side effects of other drugs

opiates

agonists reduce motility to reduce release of ach and antagonists increase ach

eg loperamide/imodium

imodium

high fpm so remain confined to gut wall and so no addiction issues as is an opiate

absence of enteric neurons in rectum

hirschprung's disease