GI Phys Gastric Secretion Flashcards
What are the five secretory products of the stomach
- Hydrogen Ion- This activates the conversion of Pepsinogen into Pepsin
- Pepsinogens- Released by chief cells, chiefs fans have pep remember, gets converted to pepsin which helps digest proteins
- Mucus- Lubricates food, released by mucus cells
- Intrinsic factor- necessary for vit B12 absorption
- Water- Dissolves and dilutes ingested material
Where is the oxyntic gland mucosa of the stomach located?
Located throughout the fundus and the body of the stomach
Where is the pyloric gland mucosa of the stomach located?
Located throughout the antrum of the stomach
What cell types are present in the oxyntic gland mucosa and what is released?
Parietal cells- HCL and IF
Chief Cells- Pepsin
What cell types are present in the pyloric gland area?
G cells- Gastrin
Mucus cells- mucus
D cells- somatostatin
In regards to the gastric gland, what cell types lie near the top of the gland?
mucous cells
Chief cells are located where in the gastric gland?
Near the bottom
What are the stem cells of the gastric gland?
Mucous neck cells,
Mechanism of acid secretion…kno
SLIDE 5
What is the potential difference across the cell membranes of the mucosa in the esophagus?
-15
What is the potential difference across the cell membranes of the mucosa in the stomach
-60 - -80
Aspirin and Ethanol do what to the potential difference?
Decrease it by disrupting cell membranes and leading to the separation of charges across the mucosa
The concentration of what ions in gastric juice vary with the rate of secretion?
As secretion goes up, more Hydrogen ions are secreted and less Na is secreted
The three major stimulants of gastric acid secretion?
Ach, Gastrin, Histamine
Yes, Gatrin can stimulate the generation of H+ by itself, but what is its most important Acid generating function?
It stimulates the release of Histamine from Enterochromaffin-like cells