Gastric Secretion Flashcards
What are the 4 parts of the stomach?
Fundus
Body
Antrum
Pylorus
What is the function of the fundus?
Storage
What is the function of the body of the stomach?
Storage Mucus production HCL production Pepsiongen production Intrinsic factor production
What is the function of the antrum?
Mixing/grinding Gastrin production ( GI hormone)
What is the function of the pylorus?
Secretes mucus, gastrin and pepsinogen.
What is the oesophageal sphincter?
Connection between oesophagus and stomach that prevents food passing back up.
What is the pyloric sphincter?
Connection between stomach and duodenum.
What are the 3 cell types in gastric glands?
Mucous neck cells(mucous) Chief cells(pepsinogen) Parietal cells(HCL and intrinsic factor)
What happens to pepsinogen when the Ph in the stomach drops below 3?
Cleaved by acid hydrolysis into its active form, pepsin.
Which 3 mechanisms control gastric acid secretion?
Neurocrine (vagus/local reflexes)
Endocrine (gastrin)
Paracrine (histamine)
What is the cephalic phase?
When gastric secretion occurs before the food enters the stomach. This is stimulated by sight,smell and taste of food.
What is the gastric phase?
Arrival of food in the stomach causing distention.
What are enterogastrones?
Hormones released from gland cells in the duodenal mucosa in response to acid.
What is the function of enterogastrones?
To prevent acid build up in the dunodeum by inhibiting gastric acid secretion and reducing gastric emptying( which inhibits motility).
What is pepsinogen?
A zymogen which is the inactive form of pepsin secreted by chief cells.
