#1
Which chamber of the heart receives oxygen-rich blood from the lungs?
Left atrium
ExplanationReceives oxygen-rich blood from the lungs.
#2
What is the purpose of heart valves?
To regulate blood flow and prevent backflow
ExplanationRegulates blood flow and prevents backflow.
#3
What is the approximate size of an adult human heart?
About the size of a fist
ExplanationApproximately the size of a fist.
#4
Which blood vessels supply oxygenated blood to the heart muscle itself?
Coronary arteries
ExplanationSupply oxygenated blood to the heart muscle.
#5
What is the approximate resting heart rate for a healthy adult?
60-80 beats per minute
ExplanationApproximately 60-80 beats per minute.
#6
Which of the following is NOT a major blood vessel connected to the heart?
Carotid artery
ExplanationNot a major blood vessel connected to the heart.
#7
Which vessel carries deoxygenated blood from the heart to the lungs?
Pulmonary artery
ExplanationCarries deoxygenated blood to the lungs.
#8
What is the function of the sinoatrial (SA) node in the heart?
To conduct electrical impulses and initiate heartbeats
ExplanationConducts electrical impulses and initiates heartbeats.
#9
What causes the lub-dub sound of the heartbeat?
Closure of the atrioventricular valves (tricuspid and mitral valves)
ExplanationClosure of the atrioventricular valves.
#10
Which part of the nervous system primarily controls heart rate?
Parasympathetic nervous system
ExplanationPrimarily controls heart rate.
#11
Which layer of the heart wall is responsible for contracting and pumping blood?
Myocardium
ExplanationResponsible for contracting and pumping blood.
#12
What is the term for the relaxation phase of the heart's pumping cycle?
Diastole
ExplanationRelaxation phase of the heart's pumping cycle.
#13
Which of the following factors does NOT affect heart rate?
Eye color
ExplanationDoes not affect heart rate.
#14
What is the medical term for a rapid heartbeat, typically more than 100 beats per minute?
Tachycardia
ExplanationRapid heartbeat, typically more than 100 beats per minute.
#15
Which hormone is responsible for increasing heart rate during times of stress or danger?
Epinephrine
ExplanationIncreases heart rate during stress or danger.
#16
Which of the following hormones increases heart rate?
Adrenaline
ExplanationIncreases heart rate.