Cardiac Physiology Summary Quiz

Questions and Answers

What is the composition of the intima, the innermost layer of arteries and veins?

A single layer of endothelial cells

What determines the permeability of capillaries?

Tightness of the endothelial cell junctions

What gives resistance to the flow of blood through arteries and generates pressure?

Tonic contraction of smooth muscle

Why are veins sometimes called 'capacitance vessels'?

They have the capacity to hold more blood than arteries Signup and view all the answers

What does compliance refer to in the context of blood vessels?

The distensibility of the vessel Signup and view all the answers

Which vessels are known as 'capacitance vessels'?

Veins Signup and view all the answers

What is the composition of the media, or middle layer, of arteries and veins?

Smooth muscle and elastin Signup and view all the answers

What is the primary time when blood flows through coronary arteries?

During diastole when the heart muscle relaxes Signup and view all the answers

How does more diastolic time affect blood flow to the myocardium?

Increases blood flow to the myocardium Signup and view all the answers

What effect does more diastolic time have on ventricular filling?

Increases ventricular filling Signup and view all the answers

How does increased diastolic time affect preload and stroke volume (SV)?

Increases preload and enables better SV Signup and view all the answers

In an athlete, what effect does increased diastolic time have on maximal heart rate (HR) for performance?

Creates more room for HR to eventually increase to maximal levels Signup and view all the answers

How much can Person A, an Olympic athlete, increase their cardiac output (CO) due to only the increase in HR?

By ~230% Signup and view all the answers

How much can Person B, not an athlete, increase their CO due to only the increase in HR?

By ~160% Signup and view all the answers

What is the resting HR of Person A, the Olympic athlete?

60 Signup and view all the answers

What is the resting HR of Person B, who is not an athlete?

75 Signup and view all the answers

What influences stroke volume?

Preload, contractility, and afterload Signup and view all the answers

In which part of a vessel does laminar flow occur?

Center Signup and view all the answers

What can turbulent flow lead to?

Thrombus formation Signup and view all the answers

What primarily alters blood flow in the vascular system?

Resistance through vasodilation and vasoconstriction Signup and view all the answers

What is cardiac output influenced by?

Heart rate and stroke volume Signup and view all the answers

What is resistance determined by?

Viscosity, length, and vessel radius Signup and view all the answers

What determines stroke volume (SV) through the Frank-Starling law?

End-diastolic volume (EDV) Signup and view all the answers

What is the primary factor affecting contractility?

Ca++ availability Signup and view all the answers

What determines afterload?

Arterial resistance Signup and view all the answers

What primarily regulates blood pressure through vasoconstriction?

Sympathetic nervous system Signup and view all the answers

What regulates blood pressure through negative feedback reflex?

Baroreceptors in the carotid sinus Signup and view all the answers

What strengthens the heart muscle, increasing contractility and stroke volume even at rest?

Athletic training Signup and view all the answers

What can lead to a lower resting heart rate and increased stroke volume at normal blood pressure?

Elevated contractility Signup and view all the answers

Study Notes

Cardiac Physiology Summary

End-diastolic volume (EDV) determines stroke volume (SV) through the Frank-Starling law
The force of heart contraction is proportional to initial sarcomere length (preload) and ventricle muscle stretch
SV can be adjusted based on venous return, but overstretching limits effective contractions
Factors affecting SV include venous return, contractility, and afterload
Contractility is independent of preload and can be affected by heart damage, hypoxia, and Ca++ availability
Afterload is determined by arterial resistance and affects heart workload and oxygen demand
Heart workload increases with factors that increase heart rate, preload, contractility, or afterload
Heart rate is primarily determined by the balance between the sympathetic and parasympathetic nervous systems
The sympathetic nervous system regulates blood pressure through vasoconstriction, while the parasympathetic system has little effect on vascular tone
Baroreceptors in the carotid sinus and aortic arch regulate blood pressure through negative feedback reflex
Athletic training strengthens the heart muscle, increasing contractility and stroke volume even at rest
Elevated contractility can lead to a lower resting heart rate and increased stroke volume at normal blood pressure

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Description

Test your knowledge of cardiac physiology with this summary quiz. Explore concepts such as stroke volume, Frank-Starling law, contractility, afterload, and the influence of the autonomic nervous system on heart rate and blood pressure regulation.