Human Circulatory System Practice Questions
19 free Human Circulatory System practice questions for the General Science. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
What is the main function of the human circulatory system?
- A To digest food within the stomach
- B To transport substances around the body
- C To control body movements and posture
- D To produce hormones exclusively
Correct answer: To transport substances around the body
The circulatory system transports oxygen, nutrients, hormones, and waste materials throughout the body. It helps cells receive what they need and remove harmful substances.
Which organ acts as the main pumping organ of the circulatory system?
- A Lungs
- B Kidney
- C Heart
- D Liver
Correct answer: Heart
The heart is a muscular organ that pumps blood through blood vessels. Its rhythmic contractions maintain blood circulation in the body.
How many chambers are present in the human heart?
- A Two
- B Three
- C Four
- D Five
Correct answer: Four
The human heart has four chambers: two atria and two ventricles. This arrangement helps separate oxygenated and deoxygenated blood.
Which chamber of the heart receives oxygen-rich blood from the lungs?
- A Right atrium
- B Left atrium
- C Right ventricle
- D Left ventricle
Correct answer: Left atrium
The left atrium receives oxygenated blood from the lungs through the pulmonary veins. This blood then moves into the left ventricle for pumping to the body.
Which blood vessel carries oxygen-rich blood from the heart to the rest of the body?
- A Pulmonary artery
- B The aorta
- C Vena cava
- D Pulmonary vein
Correct answer: The aorta
The aorta is the largest artery in the body and carries oxygen-rich blood from the left ventricle. It distributes this blood to body tissues through its branches.
Which blood vessels usually carry blood away from the heart?
- A Veins
- B Arteries
- C Capillaries
- D Lymph vessels
Correct answer: Arteries
Arteries carry blood away from the heart. Most arteries carry oxygenated blood, except the pulmonary artery, which carries deoxygenated blood to the lungs.
Which blood vessels usually carry blood toward the heart?
- A Arteries
- B Veins
- C Capillaries
- D Aorta
Correct answer: Veins
Veins carry blood toward the heart. Most veins carry deoxygenated blood, except the pulmonary veins, which carry oxygenated blood from the lungs.
Which type of blood vessel allows exchange of gases, nutrients, and wastes between blood and tissues?
- A Arteries
- B Veins
- C Capillaries
- D Pulmonary artery
Correct answer: Capillaries
Capillaries are tiny, thin-walled blood vessels that connect arteries and veins. Their thin walls allow exchange of oxygen, carbon dioxide, nutrients, and waste materials.
Which component of blood mainly carries oxygen?
- A Platelets
- B White blood cells
- C Red blood cells
- D Plasma proteins
Correct answer: Red blood cells
Red blood cells contain haemoglobin, which binds and transports oxygen. They carry oxygen from the lungs to body tissues.
Which pigment in red blood cells helps transport oxygen?
- A Chlorophyll
- B Haemoglobin
- C Melanin
- D Insulin
Correct answer: Haemoglobin
Haemoglobin is an iron-containing pigment present in red blood cells. It combines with oxygen in the lungs and helps deliver it to tissues.
Which blood cells help the body fight infections?
- A Red blood cells
- B White blood cells
- C Platelets
- D Plasma cells only
Correct answer: White blood cells
White blood cells are part of the body's immune defense. They help identify and destroy disease-causing microorganisms and other harmful substances.
Which component of blood is mainly responsible for clotting?
- A Red blood cells
- B Plasma water
- C Oxygen
- D Platelets
Correct answer: Platelets
Platelets help in blood clotting at the site of injury. They form a plug and release substances that help stop bleeding.
What is plasma in blood?
- A A solid part made only of cells
- B The liquid part of blood
- C A pigment that carries oxygen
- D A valve in the heart
Correct answer: The liquid part of blood
Plasma is the liquid part of blood, mostly made of water. It carries nutrients, hormones, waste products, and blood cells throughout the body.
Which side of the human heart mainly pumps deoxygenated blood to the lungs?
- A Left side
- B Upper side only
- C Lower side only
- D Right side
Correct answer: Right side
The right side of the heart receives deoxygenated blood from the body. It pumps this blood to the lungs for oxygenation.
Which side of the human heart mainly pumps oxygenated blood to the body?
- A Right side
- B Left side
- C Back side only
- D Septum
Correct answer: Left side
The left side of the heart receives oxygen-rich blood from the lungs. It pumps this blood to all parts of the body through the aorta.
What is the function of valves in the heart?
- A To produce red blood cells
- B To prevent backflow of blood
- C To digest fats
- D To pump blood into the arteries
Correct answer: To prevent backflow of blood
Heart valves ensure that blood flows in one direction. They prevent blood from flowing backward between chambers or into blood vessels.
The blood circulation between the heart and lungs is called:
- A Systemic circulation
- B Pulmonary circulation
- C Coronary circulation
- D Hepatic portal circulation
Correct answer: Pulmonary circulation
Pulmonary circulation is the movement of blood between the heart and lungs. It allows deoxygenated blood to release carbon dioxide and pick up oxygen.
The blood circulation between the heart and the rest of the body is called:
- A Pulmonary circulation
- B Systemic circulation
- C Lymphatic circulation
- D External circulation
Correct answer: Systemic circulation
Systemic circulation carries oxygenated blood from the heart to body tissues. It also returns deoxygenated blood from the tissues back to the heart.
Why is human circulation called double circulation?
- A Blood flows through two separate hearts
- B The heart is passed through twice per cycle
- C The heart has two atria and two ventricles
- D Blood flows only through two major arteries
Correct answer: The heart is passed through twice per cycle
In humans, blood passes through the heart twice during one complete cycle: once through the lungs and once through the body. This makes circulation efficient and helps keep oxygenated and deoxygenated blood separate.