Gastric Motility Prunuske Flashcards
Gastroparesis
Delayed stomach emptying
Increased gastric motility (too fast)
Dumping
What neurotransmitters control receptive relaxation of the stomach?
VIP
NO
Is vagal release of ACh during accomodation associated with contraction or relaxation of the stomach?
RELAXATION
What is the Gastroileal reflex?
Causes ileoceccal valve to relax after transfer contents from small to large bowel
What is the Gastrocolic reflex?
Induces the need to defecate after ingesting a meal
biggest difference between gastric and pancreatic lipase
Gastric can function in a lower pH environment (3-6)
Pancreatic lipase at higher pH where more bicarbonate has been secreted
What are 2 molecules that can be absorbed by diffusion out of the stomach?
Aspirin
Alcohol
What condition is associated with absorption of alcohol and aspirin?
Gastritis
Gastric trituration?
Emptying of liquids involves proximal stomach (tonic) and solids involves antral pump (phasic).
What is the Basic Electrical Rhythm (BER) of peristalsis?
3 to 5 waves per minute in the stomach
What 3 things inhibit gastric contractions and emptying?
Acid in duodenum via neural (enteric and vagal)and hormonal (secretin and somatostatin) mechanisms
Fat in duodenum via CCK hormone mechanisms and via enteric neural mechanisms
Osmolality of the duodenal contents via enteric neural mechanisms and perhaps hormonal mechanisms (GIP)
What molecule controls the migrating motor complex? AKA the housekeeping function to remove indigestible material during FASTING
Motilin
Why are some drugs (like macrolides) associated with diarrhea?
Because they stimulate intense contractions and cause the pylorus to open fully!
Phase III of migrating motor complex
How do you get your tummy to stop making noises when youre hungry?!
Eat. duh.
It decreases motilin so your Migrating Motor complex quiets down
Congenital condition where pylorus fails to relax after a meal leading to malnutrition and dehydration
Pyloric stenosis
Common cause of Gastroparesis?
Diabetic neuropathy involving the vagus and enteric nerves in the stomach
What is Dumping Syndrome?
Rapid gastric emptying often due to gastric bypass surgery
*Rapid entry of gastric contents into duodenum represents an osmotic challenge, water moves into lumen resulting in hypovolemia and decreased BP.
Peptic Ulcer disease
Scarring and ulcers near pylorus can delay emptying or in duodenal ulcers can lead to rapid gastric emptying due to loss of duodenal negative feedback mechanisms.
What is retching?
Contraction of abdominal muscles, relaxation of esophagus but NO VOMITING
Where is the vomiting center in the brain?
Medulla
How do you end up with a larger contraction in the stomach?
Summation….more action potentials produces a larger contraction.
What happens to contractions as the reach the closed pyloric sphincter?
Strengthen and speed up
