Q.1 Which chamber of the heart receives oxygenated blood from the lungs?
Right atrium
Left atrium
Right ventricle
Left ventricle
Explanation - The left atrium receives oxygenated blood from the pulmonary veins after it returns from the lungs.
Correct answer is: Left atrium
Q.2 What is the main function of the cardiovascular system?
Produce hormones
Transport nutrients and oxygen
Store energy
Protect bones
Explanation - The cardiovascular system circulates blood, delivering oxygen and nutrients while removing waste products.
Correct answer is: Transport nutrients and oxygen
Q.3 Which blood vessel carries blood away from the heart?
Veins
Arteries
Capillaries
Venules
Explanation - Arteries carry blood away from the heart, usually oxygenated except in the pulmonary circulation.
Correct answer is: Arteries
Q.4 Which valve prevents backflow of blood into the left atrium?
Tricuspid valve
Mitral valve
Pulmonary valve
Aortic valve
Explanation - The mitral (bicuspid) valve prevents blood from flowing backward from the left ventricle to the left atrium.
Correct answer is: Mitral valve
Q.5 What is the largest artery in the human body?
Pulmonary artery
Carotid artery
Aorta
Femoral artery
Explanation - The aorta is the largest artery, carrying oxygenated blood from the left ventricle to the body.
Correct answer is: Aorta
Q.6 Which side of the heart pumps deoxygenated blood to the lungs?
Left side
Right side
Both sides
Neither side
Explanation - The right side of the heart pumps deoxygenated blood through the pulmonary arteries to the lungs.
Correct answer is: Right side
Q.7 Which blood vessels have walls thin enough for gas exchange?
Arteries
Capillaries
Veins
Arterioles
Explanation - Capillaries are one cell thick, allowing exchange of gases, nutrients, and wastes with tissues.
Correct answer is: Capillaries
Q.8 Which vein carries oxygenated blood?
Pulmonary vein
Superior vena cava
Inferior vena cava
Jugular vein
Explanation - The pulmonary vein is the only vein that carries oxygenated blood, returning it from the lungs.
Correct answer is: Pulmonary vein
Q.9 What is the function of the sinoatrial (SA) node?
Pump blood
Regulate blood pressure
Act as pacemaker
Close heart valves
Explanation - The SA node generates electrical impulses, setting the rhythm of the heartbeat.
Correct answer is: Act as pacemaker
Q.10 Which structure separates the right and left sides of the heart?
Septum
Aorta
Valve
Atrium
Explanation - The septum is a wall that separates the right and left chambers of the heart.
Correct answer is: Septum
Q.11 Which valve is located between the right atrium and right ventricle?
Mitral valve
Tricuspid valve
Aortic valve
Pulmonary valve
Explanation - The tricuspid valve regulates blood flow from the right atrium to the right ventricle.
Correct answer is: Tricuspid valve
Q.12 Which type of blood circulation supplies blood to the lungs?
Systemic circulation
Pulmonary circulation
Coronary circulation
Portal circulation
Explanation - Pulmonary circulation carries deoxygenated blood to the lungs and returns oxygenated blood to the heart.
Correct answer is: Pulmonary circulation
Q.13 Which chamber of the heart has the thickest wall?
Right atrium
Left atrium
Right ventricle
Left ventricle
Explanation - The left ventricle has the thickest wall because it pumps blood to the entire body.
Correct answer is: Left ventricle
Q.14 What type of muscle tissue makes up the heart?
Smooth muscle
Skeletal muscle
Cardiac muscle
Connective tissue
Explanation - The heart is composed of cardiac muscle, which is striated and involuntary.
Correct answer is: Cardiac muscle
Q.15 Which blood component is primarily responsible for clotting?
Red blood cells
White blood cells
Plasma
Platelets
Explanation - Platelets help in clot formation by releasing clotting factors.
Correct answer is: Platelets
Q.16 Which artery supplies blood to the heart muscle itself?
Carotid artery
Coronary artery
Femoral artery
Subclavian artery
Explanation - The coronary arteries provide oxygen and nutrients to the myocardium (heart muscle).
Correct answer is: Coronary artery
Q.17 Which vein collects blood from the lower body and delivers it to the heart?
Pulmonary vein
Superior vena cava
Inferior vena cava
Jugular vein
Explanation - The inferior vena cava returns deoxygenated blood from the lower body to the right atrium.
Correct answer is: Inferior vena cava
Q.18 What is the function of red blood cells?
Fight infections
Transport oxygen
Produce hormones
Form clots
Explanation - Red blood cells contain hemoglobin, which binds and carries oxygen to tissues.
Correct answer is: Transport oxygen
Q.19 What structure prevents backflow of blood into the right ventricle?
Aortic valve
Pulmonary valve
Mitral valve
Tricuspid valve
Explanation - The pulmonary valve prevents blood from flowing back into the right ventricle after contraction.
Correct answer is: Pulmonary valve
Q.20 Where is the apex of the heart located?
Upper right chest
Upper left chest
Lower left chest
Lower right chest
Explanation - The apex of the heart points downward and to the left, located in the lower left chest.
Correct answer is: Lower left chest
Q.21 Which blood vessels return blood to the heart?
Arteries
Capillaries
Veins
Arterioles
Explanation - Veins return deoxygenated blood to the heart except for pulmonary veins, which carry oxygenated blood.
Correct answer is: Veins
Q.22 Which valve regulates blood flow from the left ventricle into the aorta?
Mitral valve
Aortic valve
Pulmonary valve
Tricuspid valve
Explanation - The aortic valve opens to allow blood into the aorta and prevents backflow into the left ventricle.
Correct answer is: Aortic valve
Q.23 What is the average resting heart rate for adults?
20-40 bpm
40-60 bpm
60-100 bpm
100-140 bpm
Explanation - The normal adult resting heart rate is between 60 and 100 beats per minute.
Correct answer is: 60-100 bpm
Q.24 Which blood vessels connect arteries to veins?
Arterioles
Venules
Capillaries
Coronary vessels
Explanation - Capillaries form networks between arteries and veins for nutrient and gas exchange.
Correct answer is: Capillaries
Q.25 What is the double-walled sac that encloses the heart called?
Myocardium
Endocardium
Pericardium
Epicardium
Explanation - The pericardium is a protective double-layered sac surrounding the heart.
Correct answer is: Pericardium