Why Did the Smooth Muscle in Cultured Strips of Aorta

question 69

Multiple Choice

Why did the smooth muscle in cultured strips of aorta not respond to acetylcholine by relaxing, while the smooth muscle of aortic rings did?

• A)Smooth muscle cells in aortic strips are physically incapable of relaxing under any circumstances.
• B)Acetylcholine in the strips could not penetrate to the muscle cells while in the rings it could.
• C)Smooth muscle cells in aortic rings express acetylcholine receptors, while those in strips do not.
• D)The delicate endothelial layer in aortal strips had been rubbed away during dissection, while in aortal rings it remained intact.
• E)The endothelial layer in aortal strips was abnormally thickened, while in aortal rings it was not.

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Definitions:

Response Generalization

The extension of learned responses to stimuli that are similar but not identical to the conditioned stimulus in operant conditioning.

Punishment by Application

A behavioral psychology term referring to the addition of an undesirable stimulus to decrease a specific behavior.

Negative Reinforcement

A conditioning process where the removal of an unfavorable event or outcome after the display of a behavior increases the likelihood of that behavior being repeated in the future.

Operant Extinction

The process in behavioral psychology where the frequency of a previously reinforced behavior decreases when that behavior is no longer reinforced.