Asked by Tyler's Corner on Jun 17, 2024
Verified
Within normal limits, an increase in preload leads to
A) an increase in cardiac output and force of left ventricular contraction.
B) a decrease in cardiac output and force of left ventricular contraction.
C) an increase in cardiac output and a decrease in the force of left ventricular contraction.
D) a decrease in cardiac output and an increase in the force of left ventricular contraction.
E) a decrease in stroke volume and heart rate.
Preload
The degree of stretch of cardiac muscle fibers at the end of diastole, affecting the force of contraction.
Cardiac Output
The volume of blood the heart pumps per minute, a critical measure of heart function and body's demand for oxygen.
- Comprehend the stages of the cardiac cycle and the alterations in functionality throughout each stage.
Verified Answer
CH
Cowan HowesJun 19, 2024
Final Answer :
A
Explanation :
According to the Frank-Starling law of the heart, within physiological limits, an increase in preload (the end-diastolic volume or pressure that stretches the ventricles of the heart) leads to an increase in cardiac output and force of left ventricular contraction. This is because the myocardial fibers are stretched to a more optimal length for force generation.
Learning Objectives
- Comprehend the stages of the cardiac cycle and the alterations in functionality throughout each stage.
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