QuestionSBA
QuestionChoice
This is correct. Adenosine in a vasodilator which increases blood flow to the heart. During times of increased metabolic activity, decreased blood flow, or decreased myocardial pO2, the heart requires a greater flow of blood and hence adenosine is released.
10026310
a
Increased myocyte metabolic activity
QuestionChoice
This is incorrect. Adenosine is a vasodilator and hence will be released when there is a drop in blood flow to the heart, not an increase.
10026311
b
Increased blood flow to the heart
QuestionChoice
This is incorrect. Since adenosine causes vasodilation, it is produced when a greater flow of blood is needed to the heart. A drop in oxygenation of the myocardial tissue would be an example of this, as opposed to an increased oxygen partial pressure as suggested in the question.
10026312
c
Increased oxygen partial pressure in myocardial tissue
QuestionChoice
This is incorrect. Since adenosine causes vasodilation, it is produced when a greater flow of blood is needed to the heart. An increase in myocardial oxygen demand would therefore be an example of this, not a decrease.
10026313
d
Decreased myocardial oxygen demand
QuestionChoice
This is incorrect. Adenosine is a vasodilator and so will not be produced if the coronary arteries have already dilated.
10026314
e
Coronary artery dilation
Concept
Chapter
2693
3792
Coronary blood flow
Topic
159
Cardiovascular physiology
17660
Which of the following conditions would result in an increased level of adenosine in myocardial tissue?
a