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

Concept:

• Blood is a connective tissue, that has an iron-containing pigment called Haemoglobin.
• The haemoglobin gives a red colour to the blood and is responsible for the transport of O₂ molecules throughout the body.
• One heme group can carry 4 O₂ molecules at a time. Heme group remains in the ferrous state (fe²⁺) in normal conditions.
• When haemoglobin combines oxygen from the lungs it forms oxyhaemoglobin.
• Oxyhaemoglobin transports oxygen to the cells of the body.
• Oxygen gets attached to Haemoglobin because it shows an affinity towards it, but other gases such as carbon mono-oxide (CO), carbon dioxide (CO₂) also shows an affinity towards it.

Explanation:

• When the outside environment is rich in CO, and it is being inhaled, it starts to displace oxygen bind on Haemoglobin.
• The displacement occurs because CO shows several hundred times stronger affinities towards haemoglobin than oxygen, and it forms carboxyhaemoglobin.
• This leads to the scarcity of oxygen in the body, and sufficient oxygen is not available for the mind and other organs.
• Concentrations as low as 20 or 30 parts per million (PPM) can be harmful if exposed for several hours.
•  Exposure at 2,000 PPM for one hour will cause unconsciousness.
• The increased concentration of carbon mono-oxide also leads to depletion of Ozone however, this is not the direct reason for why CO is harmful to humans

Carcinogens:

• These are the cancer-causing agents, they promote carcinogenesis.
• Carcinogens stimulate normal body cells to become cancerous cells, and due to uncontrolled growth of these cells tumours are formed.
• The three main types of carcinogens are:
•  chemical carcinogens, physical carcinogens, and oncogenic (cancer-causing) viruses.

Concept:

Human circulatory system:

• The human circulatory system, also called the blood vascular system consists of a muscular chambered heart blood vessel and blood.

Heart:

• The heart is an organ that beats continuously to act as a pump for the transport of blood.
• The heart, the mesodermally derived organ, is situated in the thoracic cavity, in between the two lungs, slightly tilted to the left.
• It is protected by a double-walled membranous bag, pericardium, enclosing the pericardial fluid.

Explanation:

Arteries:

• Arteries carry oxygen-rich blood from the heart to all parts of the body.
• The arteries have thick elastic walls.
• Arteries do not have valves.
• The blood flows in one direction only.

Thus, The main function of Arteries is to carry Oxygenated blood from heart to different parts of the body.

Additional Information Veins:

• Veins are the vessels that carry carbon dioxide-rich blood from all parts of the body back to the heart.
• The veins have thin walls.
• There are valves present in veins that allow blood to flow only towards the heart.

Key Points

• In a closed blood circulation system, three types of blood vessels are present: Arteries, Veins & Capillaries

Arteries - 

• These carry blood away from the heart to different organs of the body.
• Arteries are made up of 3 layers: 

1. The intima: It is the innermost layer that is lined by endothelium (a layer of smooth muscle tissue)
2. The media: It is the middle layer that provides the strength to handle high blood pressure from the heart. The media is the thickest layer
3. The adventitia: It is the outermost layer that is in direct contact with the surrounding tissue.

Note - 

• All the arteries carry pure blood except the pulmonary artery which carries impure blood.
• The pulmonary artery takes impure deoxygenated blood into the lungs from the right ventricle.

​Hence, from the above points, it is clear that arteries​ carry blood away from the heart to different organs. This blood is usually oxygenated but in the case of the pulmonary artery, it is deoxygenated.

Important Points

Important arteries - 

Additional Information 

• Veins:
  • These carry blood away from body organs to the heart.
  • The walls of veins are thin as compared to the arteries because the pressure of blood flow is low.
• Capillaries:
  • These are present in organs, and these are the vessels through which exchange takes place.

The correct answer is 7.4.

• The approximate value of the pH of Human blood is 7.4.

Important Points

• Acidity and alkalinity are measured with a logarithmic scale called pH.
  • pH is the negative logarithm of the hydrogen ion concentration: pH = −log [H+]
  • The square brackets around the H+ mean "concentration" relative to pure water.
• A pH less than 7 is acidic and a pH greater than 7 is basic.
• An acid is a substance that donates hydrogen ions.
  • An acid is dissolved in water, the balance between hydrogen ions and hydroxide ions is shifted. there are more hydrogen ions than hydroxide ions in the solution and makes the solution is acidic.
• A base is a substance that accepts hydrogen ions.
  • A base is dissolved in water, the balance between hydrogen ions and hydroxide ions shifts the opposite way. Because the base "soaks up" hydrogen ions, the result is a solution with more hydroxide ions than hydrogen ions and makes the solution alkaline.

Key Points

Concept-

• Blood is a body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells.
• Human blood is composed of blood cells and blood plasma
• Coagulation is an important biological process as it stops the bleeding of blood.

Key Points

• Platelets are also known as thrombocytes.
• Platelets are tiny blood cells that help your body form clots to stop bleeding. If one of your blood vessels gets damaged, it sends out signals to the platelets.
• The platelets then rush to the site of damage and form a plug (clot) to fix the damage.
• The process of spreading across the surface of a damaged blood vessel to stop bleeding is called adhesion. This is because when platelets get to the site of the injury, they grow sticky tentacles that help them stick (adhere) to one another. They also send out chemical signals to attract more platelets.
• The additional platelets pile onto the clot in a process called aggregation.

Additional Information

• Human blood is composed of blood cells and blood plasma.
• Blood cells consist of erythrocytes (RBC), leukocytes (WBC).The iron protein called haemoglobin is present in RBC. The function of RBC is to distribute oxygen to each cell of the body.
• Leukocytes are responsible for the immune system of the body. White blood cells are further divided into eosinophil, basophil, monocyte, lymphocyte, and neutrophils.
• The lymphocyte is a specialized type of white blood cells. Natural killer cells, T cells, and B cells are included in lymphocytes.
• Basophil is a type of white blood cell. Histamine enzyme is secreted by the basophils when activated.
• A monocyte is a type of white blood cell and a type of phagocyte.

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.