(F) L5: GITP Function: Stomach Flashcards
Major Zones
- Important for mucus secretion
- The mucus protects the lining of the stomach
Cardiac
Major Zones
Consists of the 2 significant cells: Parietal and Chief Cells
Body
Major Zones
- The location or secretion site of HCl, enzymes, mucus, and intrinsic factors due to the presence of the different cells
Body
Major Zones (Body)
These cells secrete mucus
Surface Epithelial Cells
Major Zones (Body)
These secrete HCl and intrinsic factors
Parietal Cells
Major Zones (Body)
This gives the stomach its acidic pH, which is important for digestion
HCl
Major Zones (Body)
This binds with vitamin B12 in order to be protected from the stomach’s acidity
Intrinsic Factors
Major Zones (Body)
These are responsible for the synthesis and secretion of serotonin
Enterochromaffin Cells
Major Zones (Body)
These produce pepsinogen (type 1 or 2)
Chief Cells
Major Zones (Body)
This, when combined with HCl will be deactivated and converted to pepsin
Pepsinogen
Note: Pepsin is the activated form of pepsinogen
Major Zones
This houses the antrum, pyloric canal, and sphincter
Pyloric
Major Zones (Pyloric)
This portion is made up of G cells which secretes gastrin
Antrum
Major Zones (Pyloric)
This is the primary GI hormone that stimulates the parietal cells to secrete gastric acid or HCl
Gastrin
Major Zones (Pyloric)
These portions (2) are important to prevent the direct passing through of the stomach contents into the intestines
- Pyloric canal
- Sphincter
What is the end product of digestion in the stomach?
Chyme/Gastric Secretion
Stimuli for Gastric Secretion
Gastric secretions occur in response to various stimuli, when gastric fluid decreases in pH, it is usually less than what?
3.5
Note: That pH is deadly for most microbes
Stimuli for Gastric Secretion
This acid protects the stomach from foreign microorganisms
Gastric Acid
Stimuli for Gastric Secretion
Consists of the vagal nerves (for smelling) which stimulates the stomach to secrete gastric fluid
Neurologic Stimuli
Stimuli for Gastric Secretion
This is due to the expansion of the mucosal lining
Stomach Distention
Stimuli for Gastric Secretion
The stomach secretes these breakdown products of proteins (usually amino acids, proteins, and polypeptides) which usually means that something needs to be digested
Secretagogues
Stimuli for Gastric Secretion
The most potent stimulus for gastric fluid secretion
Gastrin
Regulators of Gastric Secretions
These (2) are produced by the pancreas, not the stomach
- Secretin
- Cholecystokinin (CCK)
Regulators of Gastric Secretions
These (2) inhibit gastric secretion
- Gastric Inhibitory Polypeptide (GIP)
- Vasoactive Intestinal Polypeptide (VIP)
Regulators of Gastric Secretions
Produced by the pancreas:
A. Is secreted by K cells
B. Is secreted by H cells
C. Both
D. Neither
C. Both