Biology · General Awareness

Human Circulatory System

818 Questions

The human circulatory system explores the network of blood vessels, heart valves, and structural pathways. Test items often target blood flow sequences and specific vascular functions. Mastering these details is vital for biology preparation.

Heart valves and chambersBlood vessels and venulesArteries of the bodyBlood supply to organsCentral nervous system supply

Human Circulatory System Questions

Multiple choice

Veins have valves to

  1. prevent back flow of blood

  2. prevent the collapse of the vein

  3. maintain its position in the body

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Veins collect blood from different organs and bring it back to the heart. They do not require thick walls as found in arteries because the blood is not under pressure. However, veins have valves that ensure that the blood flows only in one direction towards the heart and thus, prevent back flow of blood.

Multiple choice

Which of the following statements is/are false?

a. Blood pressure is measured by using an instrument called sphygmomanometer. b. Systolic pressure is the minimum pressure in the arteries during the relaxation phase of the heart. c. One of the functions of the lymph is to help remove the waste products like fragments of dead cells, etc.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option as this statement is false. Diastolic pressure is the minimum pressure in the arteries during the relaxation phase of the heart.

Multiple choice

Which of the following is the function of the pulmonary artery?

  1. It carries oxygenated blood from the left ventricle to all the parts of the body.

  2. It carries oxygenated blood from the lungs back to the heart.

  3. It carries deoxygenated blood from all the parts of the body, except lungs, back to the heart.

  4. It carries deoxygenated blood from the right ventricle to the lungs.

  5. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the correct option as the function of the pulmonary artery is to carry deoxygenated blood from the right ventricle to the lungs.

Multiple choice

Which of the following facts about the lymphatic system is incorrect?

  1. Lymph is light yellow in colour.

  2. The lymphatic system aids the immune system.

  3. Its movement depends on the motions of the muscle and joint pumps.

  4. Like blood, it flows throughout the body in both directions.

  5. It returns proteins and fluids from circulation to tissues.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

It always flows only in one direction from tissues to heart.

Multiple choice

Which organ has a role in clearing out red blood cells after the end of their life span?

  1. Bone marrow

  2. Liver

  3. Lungs

  4. Spleen

  5. Arteries
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Blood is made in the bone marrow and also in the spleen. Red blood cells only live for about 120 days. They are then cleared out by the spleen. Following removal of the spleen, the liver primarily takes over the role of filtering out the older red blood cells. Other organs may also contribute to red cell removal such as heart. However these other organs cannot completely compensate for the loss of the spleen.

Multiple choice

Which of the following statements is/are false?

a. In phloem, conduction may be bidirectional or from storage organs to growing parts of plants. b. The blood plasma contains protein fibers and cells called blood corpuscles. c. Striated, smooth and cardiac muscles perform movement by contraction and relaxation.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option as this is a false statement. The blood plasma does not contain protein fibers, but contains cells called blood corpuscles.

Multiple choice

The velocity of blood is the maximum in

  1. large veins

  2. small veins

  3. venules

  4. capillaries
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Velocity (V) is proportionate to flow (Q) divided by the area of conduit (A). Therefore, the average velocity of the blood is high in the aorta, declines steadily in the smaller vessels and is the lowest in the capillaries, which have 1000 times the total cross-sectional area of aorta.

Multiple choice

A vessel has thin muscular walls and wider lumen with three pocket shaped valves. Which of the following is true for the vessel?

  1. It carries oxygenated blood away from the heart.

  2. It carries deoxygenated blood away from the heart.

  3. It carries deoxygenated blood towards the heart.

  4. It carries oxygenated blood towards the heart.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Veins are the vessels with valves and carry deoxygenated blood towards the heart. Valves help in circulating blood from lower parts of body against gravity.

Multiple choice

Which of the following is measured by sphygmomanometer?

  1. Pressure exerted by blood on arterial wall

  2. Pressure exerted by blood on ventricular wall

  3. Pressure exerted by blood on capillary wall

  4. Pressure exerted by blood on cardiac wall
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Blood pressure is the pressure exerted by blood on arterial wall.