Digestive 1.2 Stomach Flashcards
Where in the stomach does accommodation post-prandiale (relaxation réceptive) occur and what hormones trigger it?
In proximal:
VIP, NO (just like oesophagos SOI)
What areas of the stomach form the Zone pacemaker
up to where does this go?
jonction antre-corps- cellules de Cajal
propagation antre gastrique jusqu’a caecum
Role of motiline in stomach?
Stimulates stomach contractions inter digestion (when not eating)
What are the signals for stomach vidange (during eating)?
Gastrine (Ach stimulates release of gastrine)
What regulates rate of stomahc emptying?
The duodenum ->FREIN DUODÉNAL
The stomach needs to release at a certain rate so that the intestines have time to absorb
detects HCl levels and osmolarity
mediated by
(CCK),
sécrétine,
GIP et
gastrine
The pylore opens after the particles have been treated and broken
Why Vidange gastrique liquides et solides est inégale?
Solids need to be broken all the way to <1mm
Put these in order of digestion (faster to slower):
Lipides Glucides Protéines
Glucides < Protéines < Lipides
Cells, 2 ways of release and action of pepsinogene
Cells :Principal cells
2 ways:
1. Slow release when empty stomach that accelerates with acidity drop
2. Rapid: (when there is food; stimulated by ACh)
Action: Lipase (breakdown of fats)
Parietal cells HCl production hormones:
name the hormones, their way of action, stimulation cascade?
Stimulated by Acetylcholine, Gastrine and Histamine
Gastrine is secreted in the Vx (from the pylore) and comes around to stimulate (endocrine)
Histamine: Paracrine
ACh stimulates gastrin release
ACh and Gastrine can stimulate histamine secretion
Parietal cells HCl production mechanism:
Acetylcholine, Gastrine and Histamine stimulate receptors in cells that activate the **pompe à protons H+/K+ ATPase: takes in K+ and Releases H+ **
receptors and appropriate hormone CCK-B(), M3(), H2()
CCK-B(gastrine), M3(acetylcholine), H2(histamine)
What is an important part of HCl secretion upon passage of food in the duodenum?
secretion inhibited by: somatostatin and prostaglandine
important action after the food has already passed into the duodenum
What are two targets for parietal cell secretion inhibition?
parietal cell (proton pump) blockers (IPP)
**ANTI-H2 **-> Histamine Blockers
Why is taking IPP before meal not a good idea?
medication acts on the proton pump directly by binding covalently and blocking it until a new pump is created
that said, this means if you take right before your meal, then the medication will block the pumps that are there but then when a new meal comes, new pumps will be inserted and there is no more medication
so take it before you go to sleep.
Speak of stomach protection and why advils can cause acid reflux?
Defense against acid via secretion of mucus,
HCO3- (tampone de HCl),
prostaglandings stimulate HCO3- secretion and inhibit HCl secretion
Anti-inflammatoires (like advil) inhibent production PG -> this is why advils (or other anti-inflamatories) can cause acid reflux or stomach ulcers
