Answer:
Which two mechanisms influence the force of cardiac contraction?
Answer: End diastolic volume and sympathetic nervous system stimulation
Explanation:
Blood pressure decreases during diastole, which occurs when the heart muscle relaxes. While, blood pressure increases during systole, which occurs when the ventricles contract, pushing blood out of the right ventricle.
The cardiovascular system connects a pump to blood vessels.
Cardiac contraction is the end result of action potentials and it can be defined as a unique ability of cardiac muscle to generate a force that is independent of any load or stretch applied.
End-diastolic volume is the amount of blood in the ventricles just before systole. A person’s end-diastolic volume tends to decrease with age.
End-systolic volume is used in the hospital to determine a measurement known as stroke volume, which is the amount of blood pumped from the left ventricle with each heartbeat.
Sympathetic stimulation causes the release of the neurotransmitter norepinephrine and it increases heart rate and myocardial contractility.
The sympathetic nervous system has a wide variety of cardiovascular effects, among which are, increased cardiac contractility, peripheral vasoconstriction.
Sympathetic nervous system stimulation causes vasoconstriction of most blood vessels.
