HL pg 83-86

What does EDV stand for and how does it affect stroke volume (SV)?

EDV stands for End-Diastolic Volume, and it affects stroke volume by determining the degree of ventricular filling before contraction.

What is the Starling Principle in relation to stroke volume?

The Starling Principle states that an increase in EDV leads to an increase in stroke volume.

What factors influence the filling time of the ventricles?

Filling time is influenced by the duration of ventricular filling during diastole and the rate of blood flow to the ventricles.

What is preload and how does it relate to stroke volume?

Preload is the degree of stretching of the ventricles during filling, which depends on EDV and affects the muscle cells' ability to produce tension for contraction.

How does exercise affect EDV and SV?

EDV and stroke volume increase with exercise due to enhanced ventricular filling and contractility.

What factors affect End-Systolic Volume (ESV)?

Factors affecting ESV include preload, contractility, and afterload.

What is contractility in the context of cardiac function?

Contractility refers to the force of cardiac contraction, which influences stroke volume.

What is afterload and how does it affect stroke volume?

Afterload is the tension the ventricle must produce to open the semi-lunar valves; increased afterload decreases stroke volume and increases ESV.

How do ACE inhibitors lower blood pressure?

ACE inhibitors lower blood pressure by dilating blood vessels, preventing the formation of Angiotensin II, decreasing preload and afterload, reducing blood volume, promoting diuresis, and decreasing sympathetic nervous system activity.

What is the mechanism by which calcium channel blockers lower blood pressure?

Calcium channel blockers lower blood pressure by decreasing calcium influx into cardiac myocytes, which reduces the length and strength of contractions, causes smooth muscle relaxation and vasodilation, and decreases conduction velocity at the AV node.

What is the effect of increased afterload on stroke volume and ESV?

Increased afterload leads to a decrease in stroke volume and an increase in end-systolic volume.

What role does skeletal muscle activity play in stroke volume?

Skeletal muscle activity influences blood flow to the ventricles during filling, which can affect stroke volume.

What limits preload in the heart?

Preload is limited by the physical ability of the ventricle to stretch, which is influenced by the heart's skeleton, connective tissue, and the pericardial sac.

How do increases in arterial resistance affect stroke volume?

Increases in arterial resistance lead to decreases in stroke volume, which in turn result in increases in end-systolic volume.

What is the negative inotropic effect of calcium channel blockers?

The negative inotropic effect refers to the decrease in the force of cardiac contractions caused by calcium channel blockers.

How do diuretics contribute to lowering blood pressure?

Diuretics promote diuresis, which decreases blood volume and subsequently lowers blood pressure.

What is the relationship between sympathetic nervous system activity and blood pressure as affected by ACE inhibitors?

ACE inhibitors decrease sympathetic nervous system activity, which helps to lower blood pressure.