Mcq_mini3 Local Control Of Blood Flow
- 1.
What happens to local vascular resistance following an increase in adenosine levels in the interstitial fluid surrounding the arterioles in skeletal muscle?
- A.
Does not change
- B.
Decreases
- C.
Increases
Correct Answer
B. DecreasesExplanation
RESISTANCE and Diameter are inversely relatedRate this question:
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- 2.
Local control of the circulation prevails over neural control in which of the following organs?
- A.
Brain
- B.
Skin
- C.
GI tract
- D.
Skeletal muscle
Correct Answer
A. BrainExplanation
also kidneyRate this question:
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- 3.
Which of the following will REDUCE vascular smooth muscle tone (resting tension)?
- A.
Stimulating nitric oxide (NO) production
- B.
Stimulating the intrinsic myogenic mechanism of blood vessels
- C.
Stimulating alpha-1 receptors
- D.
Stimulating beta-2 receptors
Correct Answer
A. Stimulating nitric oxide (NO) productionExplanation
Stimulating nitric oxide (NO) production will reduce vascular smooth muscle tone (resting tension). Nitric oxide is a potent vasodilator that relaxes the smooth muscle in blood vessels, leading to vasodilation and a decrease in vascular tone. This allows for increased blood flow and decreased resistance in the blood vessels.Rate this question:
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- 4.
If you occlude blood flow to a skeletal muscle for 1 minute, what changes will occur immediately following the removaI of the occlusion?
- A.
A 15-30 second period during which flow slowly increases to the normal value
- B.
A 15-30 second period during which flow is markedly higher than prior to occlusion
- C.
A rapid (less than 2 seconds) return to normal flow
Correct Answer
B. A 15-30 second period during which flow is markedly higher than prior to occlusionExplanation
This is reactive HyperemiaRate this question:
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- 5.
During vigorous exercise, skeletal muscle blood flow increases greatly. What is the circulatory adjustment most responsible for this change?
- A.
Increased beta-adrenergic receptor stimulation in skeletal muscle blood vessels.
- B.
Increased local vasodilation in skeletal muscles.
- C.
Increased cardiac stroke volume.
- D.
Increased cardiac parasympathetic stimulation.
Correct Answer
B. Increased local vasodilation in skeletal muscles.Explanation
During vigorous exercise, the demand for oxygen and nutrients by the skeletal muscles increases. To meet this demand, the circulatory system undergoes adjustments to increase blood flow to the muscles. The most responsible circulatory adjustment for this change is increased local vasodilation in skeletal muscles. Vasodilation occurs when the smooth muscles in the blood vessels relax, allowing the vessels to widen and increase blood flow. This local vasodilation in the skeletal muscles helps to deliver more oxygen and nutrients to the working muscles, enabling them to continue functioning efficiently during exercise.Rate this question:
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- 6.
A hypothetical drug given intravenously caused a decrease in mean arterial pressure and at the same time a decrease in heart rate. Which of the following could explain the actions of this drug?
- A.
Beta-1 and Beta-2 receptor agonist
- B.
Alpha-1 receptor agonist
- C.
Inhibitor of parasympathetic effects in heart muscle
- D.
Stimulator of histamine release
- E.
Beta-l and Alpha-l antagonist
Correct Answer
E. Beta-l and AlpHa-l antagonistExplanation
The drug is likely a Beta-1 and Alpha-1 antagonist, as it causes a decrease in both mean arterial pressure and heart rate. By blocking the Beta-1 receptors, the drug reduces the heart's contractility and therefore decreases heart rate. By blocking the Alpha-1 receptors, the drug causes vasodilation, which leads to a decrease in mean arterial pressure.Rate this question:
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- 7.
While jogging on a treadmill, predict how the increase in activity will affect the tone of the arterioles in the active skeletal muscles and the volume of blood flow through the active skeletal muscles (as compared to rest). tone of the arterioles in the active skeletal muscles volume of blood flow through the active skeletal muscles
- A.
increase increase
- B.
increase decrease
- C.
decrease decrease
- D.
decrease increase
- E.
no change increase
- F.
no change decrease
Correct Answer
D. decrease increaseExplanation
capillaries have no change in tone, ARTRIOLES doRate this question:
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Mar 22, 2023Quiz Edited by
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Nov 10, 2011Quiz Created by
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