GI 8 Flashcards
What are the four segment specific motilities of the stomach?
- Activity of the lower esophageal sphincter
- Gastric Motility
2b. Gastric emptying - Belching and vomiting
What is meant by the lower esophageal sphincter is Tonically active?
It is usually constricted and will relax when you swallow food
How do different chemicals affect the lower esophageal sphincter?
It contracts in response to acetylcholine and relaxes in response to NO and VIP
What are the three components of the lower esophageal sphincter?
- Internal Sphincter: Smooth muscle
- External sphincter: Crural portion of the diaphragm
- Clasp and sling fibers: Muscle of the abdominal wall
What is the Crura?
The part of the diaphragm that the esophagus passes through
What is Receptive Relaxation?
As food enters the stomach the volume increases to not increase pressure in the stomach
What does Peristalsis do in the stomach?
Mixes stomach contents and pushes food through the pyloric sphincter
What is gastric peristalsis initiated by?
The BER
How do Extrinsic factors affect gastric peristalsis?
Extrinsic factors can affect the force of contraction and not the rate at which contraction occurs
What are the Extrinsic factors that control gastric emptying?
- Stomach and intestinal contents
- Acidity
- Distension
- Hypertonicity
What stomach contents will delay gastric emptying?
Meals rich in protein or fat will delay gastric emptying
How does Acidity affect gastric emptying?
Exposure of the duodenum to acidity inhibits gastric emptying
How does Distension of the stomach affect stomach emptying?
Because higher distension increases peristaltic activity this will increase gastric emptying
How does Distension of the Duodenum affect gastric emptying?
Distension of the duodenum decreases gastric emptying
When is gastric emptying fastest in regards to tonicity?
Hypertonicity in the stomach and isotonic duodenal increases gastric emptying
