Heart Physiology

Describe the mechanism of action of the baroreceptor reflex in response to changes in blood pressure.

• The baroreceptor reflex only affects the kidneys, not the brain and heart

• The baroreceptor reflex responds to changes in temperature, not blood pressure

• The baroreceptor reflex detects changes in blood pressure and sends signals to the brain and heart to regulate it.

• The baroreceptor reflex has no role in regulating blood pressure

What is the role of baroreceptors in regulating arterial blood pressure?

• They have no role in regulating arterial blood pressure

• They cause an increase in arterial blood pressure

• They help to maintain homeostasis by signaling the cardiovascular system to adjust heart rate and blood vessel diameter in order to regulate arterial blood pressure.

• They only regulate heart rate but not blood vessel diameter

Phases of the cardiac cycle

• Atrial Systole -> Isovolumetric Ventricular Contraction -> Rapid Ventricular Ejection -> Reduced Ventricular Ejection -> Rapid Ventricular Filling -> Diastasis -> Isovolumetric Ventricular Relaxation

• Atrial Systole -> Isovolumetric Ventricular Contraction -> Rapid Ventricular Ejection -> Reduced Ventricular Ejection -> Isovolumetric Ventricular Relaxation -> Rapid Ventricular Filling -> Diastasis

• Atrial Systole -> Rapid Ventricular Ejection - > Isovolumetric Ventricular Contraction -> Reduced Ventricular Ejection -> Isovolumetric Ventricular Relaxation -> Rapid Ventricular Filling -> Diastasis

• Atrial Systole -> Isovolumetric Ventricular Contraction -> Reduced Ventricular Ejection -> Isovolumetric Ventricular Relaxation -> Rapid Ventricular Filling -> Diastasis -> Rapid Ventricular Ejection

What are the factors that affect stroke volume during the cardiac cycle?

• Diet, stress levels, and sleep patterns

• Preload, afterload, and contractility

• Blood pressure, heart rate, and cholesterol levels

• Lung capacity, body temperature, and exercise frequency

Discuss the role of sympathetic and parasympathetic nervous systems in regulating heart rate.

• Both sympathetic and parasympathetic nervous systems decrease heart rate

• Both sympathetic and parasympathetic nervous systems regulate heart rate by either increasing or decreasing it.

• The sympathetic nervous system has no role in regulating heart rate

• The parasympathetic nervous system only increases heart rate

Explain the concept of afterload and its impact on the cardiac cycle.

• Afterload is the volume of blood in the heart at the end of diastole, and it has no impact on the cardiac cycle.

• Afterload is the speed at which the heart pumps blood, and it has no impact on the cardiac cycle.

• Afterload is the amount of blood that the heart pumps during diastole, and it has no impact on the cardiac cycle.

• Afterload is the pressure or resistance that the heart must pump against to eject blood during systole, and it impacts the workload of the heart during the cardiac cycle.

How do vasodilators and vasoconstrictors influence arterial blood pressure?

• They influence arterial blood pressure by either decreasing or increasing it.

• They only influence venous blood pressure

• They have no effect on arterial blood pressure

• They cause irregular heartbeats which have no impact on blood pressure

Explain the concept of preload and its impact on the cardiac cycle.

• Preload is the volume of blood in the heart at the end of diastole, and it impacts the filling pressure of the heart during the cardiac cycle.

• Preload is the speed at which the heart pumps blood, and it has no impact on the cardiac cycle.

• Preload is the amount of blood that the heart pumps during diastole, and it has no impact on the cardiac cycle.

• Preload is the pressure or resistance that the heart must pump against to eject blood during systole, and it has no impact on the cardiac cycle.

At which stage of the Cardiac Cycle do you hear the 4th Heart sound?

• Diastasis

• Atrial Systole

• Rapid Ventricular Ejection

• Rapid Ventricular filling

Order of Electrical activity in the Hearth

• SA Node -> AV node -> Bundle of His -> Bundle branches -> Perkins Fibres

• SA Node -> AV node -> Perkinje Fibres -> Bundle of His -> Bundle branches

• SA Node -> AV node -> Bundle branches -> Bundle of His -> Perkinje Fibres

• None of these