Circulatory System MCQ Quiz - Objective Question with Answer for Circulatory System - Download Free PDF

The Correct answer is Option 2. 

Key Points8

• The fluid part of the blood is called plasma. Hence, option 2 is correct.
• Plasma:
  • Makes up about 55% of the total blood volume.
  • It is a yellowish liquid that serves as the medium for transporting nutrients, hormones, waste products, and other substances throughout the body.
• Composition of Plasma:
  • Water (~90-92%): Acts as the solvent.
  • Proteins (~7%):
  • Albumin: Maintains osmotic pressure.
  • Globulins: Play roles in immunity.
  • Fibrinogen: Essential for blood clotting.
  • Electrolytes: Sodium, potassium, calcium, etc., which maintain pH and osmotic balance.
  • Nutrients: Glucose, amino acids, and lipids.
  • Waste Products: Urea and carbon dioxide.
  • Hormones and Enzymes.
• Other Components of Blood (Non-Fluid Parts):
  • Red Blood Cells (RBCs): Carry oxygen.
  • White Blood Cells (WBCs): Fight infections.
  • Platelets: Help in blood clotting.

The ABO Blood grouping System

• The ABO blood group system is the most important blood type system (or blood group system) in human blood transfusion.

​The ABO

• Based on the presence or absence of antigen A and antigen B, blood is divided into four groups
  • ‘A, B, AB, and ‘O’ group. ​
• Blood having antigen A belongs to the ‘A’ group.
  • This blood has β-antibody in the serum.
• ​Blood with antigen B and α-antibody belongs to the ‘B’ group.
• If both the antigens are present, the blood group is called the ‘AB’ group, and the serum of this group does not contain any antibodies.
• If both antigens are absent, the blood group is called the ‘O’ group, and both α and β antibodies are present in the serum.
• Principle of Blood Grouping o Blood grouping is done on the basis of agglutination.​

Blood Groups and Donor Compatibility

The correct answer is option 3.

Key Points

• The pulmonary vein is the only vein in the human body that carries oxygenated blood. Hence, option 3 is correct.
• It transports oxygen-rich blood from the lungs to the left atrium of the heart.
• This is an exception because veins usually carry deoxygenated blood back to the heart.

Additional Information

• Cystic vein: Drains blood from the gallbladder into the portal vein (deoxygenated).
• Cardiac vein: Carries deoxygenated blood from the heart muscles to the right atrium.
• Hepatic Portal Vein: Carries nutrient-rich but deoxygenated blood from the intestines to the liver. 

The correct answer is Only (i) and (iii).

Key Points

• Arteries are blood vessels that carry blood away from the heart to various organs of the body, as stated in statement (i).
• Arteries have thick and elastic walls to withstand high pressure, making statement (ii) incorrect.
• Veins have valves that ensure blood flows only in one direction, which is correctly mentioned in statement (iii).

Additional Information

• Arteries and Veins:
  • Arteries carry oxygenated blood away from the heart, except for the pulmonary artery which carries deoxygenated blood to the lungs.
  • Veins carry deoxygenated blood back to the heart, except for the pulmonary veins which carry oxygenated blood from the lungs to the heart.
• Blood Pressure:
  • Arterial walls are thick to handle high blood pressure exerted by the heart's pumping action.
  • Veins operate under lower pressure and have thinner walls compared to arteries.
• Valves in Veins:
  • Valves in veins prevent backflow of blood, ensuring it moves towards the heart.
  • These valves are especially important in the limbs to counteract gravity.
• Elasticity of Arteries:
  • Elasticity allows arteries to expand and contract with each heartbeat, maintaining continuous blood flow.
  • This feature is crucial for the regulation of blood pressure and flow distribution.

The correct answer is the left atrium.

Key Points

• Oxygen-rich blood from the lungs enters the heart through the left atrium.
• The left atrium receives oxygenated blood from the pulmonary veins, which carry blood from the lungs.
• Once filled, the left atrium contracts, pushing blood into the left ventricle.
• The left ventricle then pumps the oxygenated blood to the rest of the body through the aorta.

Additional Information

• Pulmonary Circulation:
  • Pulmonary circulation is the movement of blood between the heart and the lungs.
  • It involves the right ventricle pumping deoxygenated blood to the lungs via the pulmonary arteries.
  • Oxygenated blood returns to the left atrium through the pulmonary veins.
• Systemic Circulation:
  • Systemic circulation moves oxygenated blood from the heart to the rest of the body.
  • The left ventricle pumps oxygenated blood into the aorta, which branches into smaller arteries and reaches tissues throughout the body.
• Heart Chambers:
  • The heart has four chambers: two atria (upper chambers) and two ventricles (lower chambers).
  • The atria receive blood, while the ventricles pump blood out of the heart.
• Valves of the Heart:
  • Heart valves ensure one-way blood flow through the heart chambers.
  • Major valves include the mitral valve (between left atrium and ventricle) and the tricuspid valve (between right atrium and ventricle).

The correct answer is AB.

Key Points

• Type AB blood is rare it’s found in less than 5% of the population.
• And it is the 'newest' of the blood types.
• Until ten or twelve centuries ago, there was little to no Type AB blood type.
• That is because type AB results from the intermingling of Type A with Type B.
• Type AB has both A and B antigens, but no antibodies.

 Additional Information

• In the years 1900–1902, K. Landsteiner divided human blood into four groups — A, B, AB, and O.
• Rh factor is a type of blood antigen discovered in 1940 by Landsteiner and A.K. s. was done by Veneer.
• Each person has a blood type (O, A, B, or AB). Everyone also has an Rh factor (positive or negative).
• The Rh factor is a protein on the covering of the red blood cells.
• If the Rh factor protein is on the cells, the person is Rh-positive.
• If there’s no Rh factor protein, the person is Rh-negative.

The correct answer is birds and Mammals.

• Birds and Mammals have a double circulatory pathway.

Key Points

• No, mixing of oxygenated and deoxygenated blood in this pathway.
• The ventricles pump it out without mixing which means two separate circulatory pathways are present in these organisms.
• Hence, these animals have double circulation.
• Fishes have single circulatory pathways of circulation which's why known as a single circulation system.
• In this system oxygenated blood is supplied to the body from where deoxygenated blood is returned to the heart. 
• In Amphibian and reptiles has incomplete circulation.
• Here oxygenated and deoxygenated blood gets to mix up within the single ventricle.

Additional Information

• Types of Circulation and Heart

The correct answer is Arteries.

Key Points

• The blood vessels that carry blood from the heart to the various parts of the body are called Arteries.
• The main artery is the aorta, the principal high-pressure duct linked to the left ventricle of the heart.
• The smaller branches of the arteries are called capillaries and arterioles.
• Veins are vessels of the blood which carry blood to the heart.
• The septum is the cartilage that divides the heart into right and left chambers, this prevents the mixing of blood.

Additional Information

The correct answer is Size - 18-25 µm. 

Key Points

Cells are the basic, fundamental, structural, and functional unit of life responsible for all life's processes, hence they are called Building blocks of life.

On the basis of the count, cells are of three types:- 1. RBCs 2. WBCs 3. Platelets. 

• RBCs are called red blood cells and help in oxygen transport from the lungs to all body organs and tissues. 
• WBCs are called white blood cells and help to fight infection and eat up all germs.
• Platelets help in blood clotting.​

Important Points

• WBCs are also called leukocytes or white corpuscles.
• The life span of WBCs is 13 to 20 days.
• Total WBCs count ranges from 4,500 to 10,000.
• WBCs are a cellular component of the blood that lacks hemoglobin, has a nucleus, is capable of mobility, and producing antibodies.
• They act as a " Soldier or Guard " of our body.
• The size of WBCs is 12 to 17 µm in diameter and about three times of RBCs.
• WBCs do not have any fixed shape, they may be circular, rhomboid or any other shape.

The correct answer is O negative.

Do not confuse with blood group O positive answer, we have provided the link below for better understanding. 

Important Points

• People with O negative blood group are considered universal donors. RBC's which they contain do not have  A, B, or Rh antigens.
• People who have a blood group of AB positive are considered as a universal recipient. Those people who have AB positive blood group have an absence of antibodies to A, B, or Rh in their blood.
• There are four major blood groups: A, B, O, and AB. Blood groups are classification as blood, they are classified on the presence and absence of antibodies and other antigens on the surface of Red blood cells.
• You can see through this link

https://www.redcrossblood.org/donate-blood/blood-types.html#:~:text=AB-, Group%20O%20can%20donate%20red%20blood%20cells%20to%20anybody.,cells%20to%20B's%20and%20AB's.

Additional Information 

• Blood is composed of four components: White blood cells, Red blood cells, plasma, and platelets.
• Red blood cells are red in colour due to the presence of Hemoglobin, which is an iron-containing protein.
• When viruses or bacteria enter the blood, then White blood cells help in fighting infections.
• Blood Plasma is a yellowish liquid component of blood that helps in the transportation of nutrients like minerals, protein, vitamins, sugars, and fats to all parts of the body.

We can see that O- is compatible to donate every other group.

The correct answer is Veins.

Key Points

• The blood vessels carrying the blood from the body towards the heart is called vein.
• Veins carry CO₂ rich blood from all parts of the body back to the heart.
• Veins carry impure blood.
  • The pulmonary vein is the only vein that carries pure blood.
  • The pulmonary vein carries the blood from the lungs to the left auricle.

Additional Information

• Arteries carry O₂ rich blood from the heart to parts of the body.
  • Arteries carry pure blood.
  • The pulmonary artery is the only artery that carries impure blood.
• The blood vessels that connect arteries and veins are called Capillaries.
• Arterioles are the branches of arteries.

The correct answer is Option 4 i.e. Pericardium

• The pericardium is the outermost covering of the Heart.
• It is a membrane enclosing the heart, consisting of an outer fibrous layer and an inner double layer of serous membrane.
• The Heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system.
• The Liver helps in digesting the fat molecules.
• The Kidney helps in removing the waste and toxins of the body by means of balancing the fluids.
• Bones help in supporting the body structurally and protect our vital organs.

The correct answer is Pulmonary Veins.Key Points

• The veins that carry oxygenated blood from the lungs to the heart are known as the pulmonary veins.
• The four primary pulmonary veins—two from each lung—that empty into the left atrium of the heart are the largest pulmonary veins. 
• The pulmonary veins are part of the pulmonary circulation.
• The main pulmonary veins receive blood from three or four feeding veins in each lung, and drain into the left atrium.
• The peripheral feeding veins do not follow the bronchial tree.
• They run between the pulmonary segments from which they drain the blood.

Additional Information

• Cardiac vein:
  • The cardiac veins returns deoxygenated blood from the myocardium to the right atrium.
• Pulmonary arteries:
  • These are blood vessels that carry oxygen-poor blood from the right side of your heart to your lungs.
• Cardiac artery:
  • These are the arterial blood vessels of coronary circulation, which transport oxygenated blood to the heart muscle.

​

The correct answer is Aorta.

Key Points

• The Aorta is the largest artery in the body.
• The Aorta begins at the top of the left Ventricle which is the Heart's muscular pumping chamber.
• The Heart pumps blood from the left ventricle into the Aorta through the Aortic valve.

Additional Information

• Coronary arteries carry oxygenated blood to the muscles of the heart.
  • Any type of hindrance in Coronary arteries causes a heart attack.
• The Pulmonary artery carries deoxygenated blood from the right ventricle to the lungs.
  • The pulmonary artery contains impure blood.
• Pulmonary veins are responsible for carrying oxygenated blood from the lungs back to the left atrium of the heart.

• The left ventricle pumps oxygenated blood into the aorta via the tricuspid aortic valve.
• The right atrium receives deoxygenated blood from the vena cavae and coronary sinus and empties it into the right ventricle.
• The right ventricle pumps deoxygenated blood into the pulmonary trunk via the pulmonary valve.
• The left atrium receives oxygenated blood from pulmonary veins and empties it into the left ventricle.

The correct answer is Villi.

• Capillaries are called very tiny blood vessels.
• The Capillaries expand like a mesh in the whole body.
• Through these capillaries, blood is transported to all parts of the whole body.
• The arteries are the blood vessels that carry blood from the heart.
• All arteries carry oxygen-rich blood, except for pulmonary and avascular arteries.
• A tube that carries blood from the body to the heart and returns back is called a 'vein'.
• 'Villy' is a structure found in the intestine that helps to absorb nutrients from the food eaten.