GI Motility Flashcards
Rhythmic segmentation
- “mixing + churning”
- Circular smooth muscle
What cations are the major controls for the BER of the interstitial cells of Cajal
Ca influx leading to depolarization
K+ efflux leading to repolarization
Neural path of Oral Glands
Stimulus -> Higher centers -> Salivatory Nucleus of Medulla
-> Otic ganglion -> Parotid
AND
-> Submandicular Ganglion -> Submandicular
SMCT1
Short chain fatty acid absorption in the LI
Muscular actions in Peristalsis
- Longitudinal muscle contracts distal to bolus widening GI Lumen
- Circular contracts proximal to bolus to propel via inhibition of VIP/NO, ATP
Fasting Motility Phases
- quiescent period
- irregular activity
- regular burst of activity
Damage to ____ nerve can result in aspiration
Recurrent Laryngeal
Gradient from intrathoracic to intra abdominal pressure is ____
12 mmHg
Hormones that DEC pressure in LES
Calcitonin gene-related peptide; GIP; Neuropeptide Y; VIP
Hormone stimulating emptying
Ghrelin
Kinetics of Liquid emptying
1st order kinetics by 12 minutes; Drink 200 ml -> 100 enter duodenum by 12 minutes
Normal T1/2 Solid emptying
<2 Hours
Pain, Vomiting/ + Acute abdomen
- Pain precedes vomiting in acute surgical abdomen
- Vomiting precedes pain in acute medical abdomen (Bowel Obstruction)
GOO
- Gastric Outflow Obstruction
- Non-bilious vomit/emesis
Prolonged nausea which precedes vomiting
Distal small or large bowel obstruction
Recurrent vomiting of bile-stained fluid
proximal small bowel obstruction
Cytotoxic drug-induced Emesis
5HT3 antagonists (Ondansetron)
Central Dopamine antagonist (Netoclopramide)
Cannabinoid receptor antagonist (Dronabinol)
Neurokinin receptor antagonist (Aprepitant)
Vestibular Emesis
H1 antagonist (Cyclizine) Muscarinic antagonist (Scopalamine)
What part of the GI tract is composed of striated?Smooth muscle?
Pharynx, Upper 1/2 Esophagus, External Anal Sphincter Striated
All other areas smooth
What factors are responsible for tonic contraction of LES between swallows?
Inherent tone in smooth muscle which is augmented by cholinergic nerves
What are the major NTs responsible for regulating contraction + relaxation of LES?
- ACh, VIP, NO, ATP
