[1] GI Secretions Flashcards
(31 cards)
How much liquid does the small intestine absorb per day?
8.5L
3 Principle Regulatory Mechanisms
Endocrine
Neurocrine
Paracrine
Define: Chemosenses
Nerve endings found on the eyes, nose, mouth, and throat
Olfactory Cells
Gustatory Cells
Common Chemical Senses
What elicits secretions?
Secretagons
How much saliva produced in a day?
1.5L
Functions of Saliva
- Moisten food
- Begin chemical digestion (amylase)
- Adjust appetite and facilitate taste
- Bacteriostatic action (bacteriolysin)
- Neutralization of refluxed gastric contents
- Aid in speech
Secretion: Chief Cell
Pepsinogen
Gastric Lipase
Secretion: Parietal Cell
HCL
IF
Secretion: G Cell
Gastrin
Secretion: D Cell
Somatostatin
Function: Gastric Lipase
Fat breakdown
Function: Pepsinogen
Peptide bond breakdown
Function: IF
Vitamin B12 Absorption
Rates of Secretion of Gastric Acid
Greater in night/morning?
Night
Function: Somatostatin
Inhibit acid secretion
Agonists of Acid Secretion
Ach: Cholinergic Nerve Terminals (Neurocrine)
Gastrin: G Cells via Bloodstream (Endocrine)
Histamine: ECL cells by Diffusion (Paracrine)
Strongest Agonist of Acid Secretion
Acetylcholine
Best Inhibitor of Acid
Acid itself when pH < 1.8
Most Important Inhibitor of Acid
Somatostatin
What is the receptor for Gastrin?
CCK2
What is the receptor for Acetylcholine?
Muscarinic Receptors
What is the receptor for Histamine?
H2 Receptors
[Lecturer “For the Exam” Question]
All of the following acts through a mechanism where you have increased cytosolic calcium except?
Histamine
pH of the Gastric Mucosal Barrier
Cell Surface: 7
Gastric Lumen: 1-2