Question 1

Question 2(b)Assertion (A): Blood is the fluid medium of the human circulatory system, responsible for transporting nutrients and excretory wastes, but it does not carry oxygen or carbon dioxide gases.Reason (R): Oxygen and carbon dioxide gases are transported through the lymph vessels from one part of the body to the other since they are in gaseous states.Both A and R are true.Both A and R are false.A is true and R is false.A is false and R is true.

Accepted Answer

Both A and R are false.Explanation — Blood is responsible for transporting nutrients and excretory wastes, along with the respiratory gases (oxygen and carbon dioxide) throughout the body. Lymph vessels do not carry the respiratory gases as lymph contains WBCs only. Absence of RBCs (i.e. Haemoglobin) makes them unable to carry oxygen or carbon dioxide.

Question 2

Question 2(d)Assertion (A): The walls of the atria are thinner as compared to those of the ventricles.Reason (R): The atria are the 'receiving chambers' as they receive blood and ventricles are the 'distributing chambers' as they pump blood into lungs and the thickest blood vessel - Aorta.Both A and R are true.Both A and R are false.A is true and R is false.A is false and R is true.

Accepted Answer

Both A and R are true.Explanation — The atria have thinner walls as they only need to pump blood a short distance into the ventricles. Ventricles are bigger in size and their walls are thicker, elastic and muscular so as to efficiently pump blood to different parts of the body with much greater force.

Question 3

Question 1(e)Differentiate between the following pairs on the basis of what is indicated within the brackets:Blood and lymph (composition)

Accepted Answer

Difference between Blood and Lymph on the basis of composition:BloodLymphNon-cellular fluid part of blood is Plasma. It makes up 55-60% of the blood.Non-cellular part of Lymph is made up of mostly water (about 94%) and the remaining 6% is made up of proteins, fats, carbohydrates, enzymes, antibodies, etc.Cellular part of blood consists of red and white cells and platelets. They make up 40-45% of the blood.Cellular part of Lymph contains only leukocytes (mostly lymphocytes). Platelets and red blood cells are absent.

Question 4

Question 2Name any four heart-related conditions that occur commonly in humans. Briefly explain the cause and symptoms of each of them.

Accepted Answer

The four heart related conditions common to humans along with their cause and symptoms are given below:Palpitations — When the heart beats too hard or too fast or sometimes even skips a beat, it is called Palpitations. Palpitations are often caused due to stress or anxiety. Sometimes, certain types of food may also cause Palpitations.Hypertension — This is a condition that occurs when blood flows through the blood vessels with a force greater than normal. This is also called High Blood Pressure. Hypertension can also strain the heart, damage blood vessels and increase the risk of heart attack or stroke.Heart attack — A heart attack is a sudden interruption of blood supply to the heart. It usually occurs due to a blood clot that prevents the flow of oxygen rich blood to the cardiac muscle. As, a result a part of the cardiac muscle dies and causes a permanent damage to the heart. Some common symptoms of a heart attack include uncomfortable pressure, tightness or squeezing pain in the centre of the chest, discomfort or pain spreading beyond the chest to the shoulders, neck, jaw, teeth or one or both arms, shortness of breath , dizziness, sweating and nausea.Cardiac Arrest — A cardiac arrest occurs when the heart suddenly stops pumping blood around the body. In cardiac arrest, a person suddenly loses consciousness and stops breathing or may have abnormal breathing. Some people experience chest pain, shortness of breath, or nausea before a cardiac arrest occurs. The common cause of cardiac arrest is coronary artery disease wherein the walls of the arteries thicken as a result of fat or plaque deposition. Less common causes include major blood loss, lack of oxygen, low potassium levels, heart failure and intense physical exercise.

Question 5

Question 3Explain — (a) Universal donor (b) Universal recipient

Accepted Answer

(a) Universal donor — The blood of O group can be given to all the groups. As blood group O has neither antigen A nor B so it doesn't cause self-clumping with any antibodies making it compatible with all blood groups. Hence, a person with O blood group is called a universal donor.(b) Universal recipient — A person with blood group AB is called a universal recipient since they can receive blood from a person with any blood group. As blood group AB has no antibodies, so there is no attack on the antigens of any blood group making it compatible to receive blood from all blood groups.

Question 6

Question 4During surgical operations or during accidents, the patient may be given blood from outside to save his life. What is the technical name of this process ? Briefly explain the precautions to be observed and taken in this process.

Accepted Answer

This process is known as blood transfusion. The following precautions are to be observed for blood transfusion:Checking the compatibility of the donor's blood group with that of the recipient.It should be made sure clinically that the blood of the donor is free from any infections.The donor's hemoglobin level is checked.

Question 7

Question 5Given alongside is a diagram of the human heart showing its internal structure. Label the parts marked 1 to 6, and answer the following questions.(a) Which type of blood is carried by the blood vessel marked 2?(b) Name the main artery which takes the blood from heart to different parts of the body?(c) Which chamber of the heart receives deoxygenated blood from the body?

Accepted Answer

The parts marked 1 to 6 are labelled below:1 → Left pulmonary artery2 → Superior vena cava3 → Left pulmonary vein4 → Right auricle5 → Left ventricle6 → Right ventricle(a) Deoxygenated blood is carried by the blood vessel marked 2 (Superior vena cava).(b) Aorta(c) Right auricle

Question 8

Question 3Match the items in Column A with those in Column B.Column AColumn B(a) Sino atrial node(i) Deoxygenated blood(b) Pulmonary veins(ii) Between right atrium and ventricle(c) Pulmonary artery(iii) Pacemaker(d) Tricuspid valve(iv) Between left atrium and ventricle(e) Biscuspid valve(v) Oxygenated blood

Accepted Answer

Column AColumn B(a) Sino atrial node(iii) Pacemaker(b) Pulmonary veins(v) Oxygenated blood(c) Pulmonary artery(i) Deoxygenated blood(d) Tricuspid valve(ii) Between right atrium and ventricle(e) Biscuspid valve(iv) Between left atrium and ventricle

Question 9

Question 1(c)Karl Landsteiner classified human blood into four categories on the basis of proteins (antigens) found on the surface of the RBCs. Compatibility of blood groups must be checked during blood transfusion. Which of the following statements are incorrect ?P. Blood group 'AB' is the universal donor as it does not contain any antibodies.Q. Blood group 'AB' is the universal recipient as it contains both the antigens 'A' and 'B'.R. Blood group 'O' is the universal recipient as it does not contain any antigens.Only ROnly P and ROnly P and QOnly Q and R

Accepted Answer

Only P and RReason — Blood group 'AB' has antigens A and B so people with AB blood group can receive blood from all types, while Blood group 'O' has neither antigen A nor B, so people with blood group O can give their blood to all the groups but can only receive blood from O blood types. Hence, a person with AB blood group is called a universal recipient, and a person with O blood group is called a universal donor.

Question 10

Question 2(d)Define Artificial pacemaker

Accepted Answer

Sometimes a mechanical device called an artificial pacemaker is placed surgically in humans if their SA node is damaged or if the electrical conduction system of the heart has problems.

Question 11

Question 3In which organ of our body does blood get oxygenated ?

Accepted Answer

Lungs

Question 12

Question 4Which side of the heart (left or right) contains oxygenated blood?

Accepted Answer

The left side of the heart contains oxygenated blood.

Question 13

Question 5(a)Write important role/roles of Pericardial fluid.

Accepted Answer

Pericardial fluid protects the heart from shocks, jerks or any mechanical stress.

Question 14

Question 5(b)Write important role/roles of Aorta.

Accepted Answer

Aorta carries oxygenated blood from the heart to all parts of the body through its branches.

Question 15

Question 5(c)Write important role/roles of Vena cavae.

Accepted Answer

The two Vena Cavae veins (Superior Vena Cava and Inferior Vena Cava) bring deoxygenated blood from all the different parts of the body to the right auricle of the heart.

Question 16

Question 6Give the functions of lymph.

Accepted Answer

Functions of lymph are —Drainage — It drains away excess tissue fluid and metabolites and returns proteins to the blood from tissue spaces.Absorption — Fats in the intestine are absorbed through lymph vessels (or lymphatics).Defence — Lymphocytes and monocytes of the lymph function to defend the body. The lymphatics also remove bacteria from the tissues.

The Circulatory System

Assertion Reason Type Questions

Long Answer Questions

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Objective Type Questions

Short Answer Questions