#1
During which phase of the cardiac cycle does the atria contract to push blood into the ventricles?
Systole
Diastole
Isovolumetric contraction
Isovolumetric relaxation
#2
What is the main function of the atrioventricular (AV) valves during the cardiac cycle?
To prevent backflow of blood into the atria during ventricular contraction
To prevent backflow of blood into the ventricles during atrial contraction
To regulate blood pressure in the arteries
To regulate heart rate
#3
Which chamber of the heart receives oxygenated blood from the lungs?
Right atrium
Left atrium
Right ventricle
Left ventricle
#4
What is the term for the relaxation phase of the cardiac cycle when the heart chambers fill with blood?
Systole
Diastole
Isovolumetric contraction
Isovolumetric relaxation
#5
Which of the following is NOT a phase of the cardiac cycle?
Atrial systole
Ventricular diastole
Ventricular relaxation
Atrial diastole
#6
What event occurs during the isovolumetric contraction phase of the cardiac cycle?
The ventricles relax and fill with blood
Both atria and ventricles contract simultaneously
The atria contract, pushing blood into the ventricles
All heart valves are closed as pressure in the ventricles rises
#7
What is the role of the semilunar valves during the cardiac cycle?
To prevent backflow of blood into the atria
To prevent backflow of blood into the ventricles
To regulate blood flow between the atria and ventricles
To regulate blood flow from the ventricles into the arteries
#8
Which chamber of the heart has the thickest muscular wall?
Right atrium
Left atrium
Right ventricle
Left ventricle
#9
What is the term for the volume of blood pumped out by each ventricle in one minute?
Cardiac output
Stroke volume
Heart rate
Venous return
#10
Which of the following events occurs during the QRS complex on an electrocardiogram (ECG)?
Atrial depolarization
Atrial repolarization
Ventricular depolarization
Ventricular repolarization
#11
Which of the following statements about the Frank-Starling mechanism is true?
It describes the regulation of heart rate by the autonomic nervous system
It is responsible for the automaticity of cardiac muscle cells
It ensures that the heart pumps out the same volume of blood it receives
It involves the release of adrenaline by the adrenal glands
#12
Which of the following factors can affect preload, a determinant of stroke volume?
Heart rate
Blood viscosity
End-diastolic volume
Afterload
#13
What is the term for the phase of the cardiac cycle when the ventricles are actively pumping blood out of the heart?
Atrial systole
Ventricular diastole
Ventricular systole
Atrial diastole
#14
Which hormone is released by the kidneys to regulate blood pressure and stimulate red blood cell production?
Insulin
Cortisol
Renin
Erythropoietin
#15
Which of the following factors can lead to an increase in heart rate?
Parasympathetic stimulation
Decrease in blood pH
Hypothermia
Increased blood pressure
#16
Which of the following is a symptom of heart failure?
Bradycardia
Tachypnea
Hypertension
Decreased jugular venous pressure