MCQ Lab 7 Digestion Flashcards
The mixture of food structure resembles what?
The layers of an onion
Where do you find food that’s eaten first?
In the curvature major
Where do you find food that’s taken up last?
In the cardia
Where in the GI tract can you find the ptyalin enzyme?
In the stomach
What’s the completely mixed content of the stomach called?
The chymus
What substance act (activate the) on Parietal cells
Acetylcholine, histamine and Gastrin
What cells does Gastrin have an effect on?
Parietal cells
Which effect does acetylcholine have on Gastric SM cells?
Stimulating effect
Which gastric juice producing cells are influenced by Acetylcholine?
Parietal cells and ECL cells
Histamine acts on which receptors?
H2 receptors
How to measure the basal HCl concentration?
By titrating 0.01 M NaOH solution after adding a couple of drops of phenolphthalein
In what way does Verapamil inhibit muscle contraction?
By Ca2+ channel inhibition
Which muscle initiates smooth muscle contraction?
MLCK, Myosin Light Chain Kinase
What pathway does muscarinic Ach receptors activate?
G-protein phospholipase C pathway
What is ED50?
The concentration of the active ingredient, when the muscle contraction is half of its maximal.
The effects of acetylcholine is mediated by which type of receptors ?
The muscarinic Ach receptors
What dissociates the Actomyosin complex?
Myosin phosphatase (MP) enzyme
What’s included in the taste sensation pathway?
Fascial (VII), glossopharyngeal (IX) and vagus (X) are involved
What are the 4 basic tastes?
Sweet, salty, sour, bitter.
Example of sweet tastes?
Sugars e.g. saccharine and saccharose
Example of salty tastes
Neutral salts of strong acids and bases
Examples of sour taste
Hydrogen ion dissociating molecules - buffers of saliva alters sensation
Examples of bitter taste
Several alkaloids e.g. strychnine, quinine, several glycosides, ether, some Mg2+ and Ca2+ salts, ammonium compounds and sulphates.
