Science & Technology · Chapter 05

63 solved questions

Chapter 5: Physiological Structure and Life Process (Blood Circulation)

Every question in this chapter, answered and explained — step-by-step solutions drawn live from the chapter library across 8 question sections.

Very Short Answer Questions12 Short Answer Questions10 Give Reason Questions8 Differentiate Between8 Long Answer Questions8 Diagram-Based Questions4 Application / Conceptual Questions11 Additional SEE Practice2

Very Short Answer Questions

1SEE Boardqb-q0

What are the three main parts of the circulatory system?

Ans.The heart, blood vessels, and blood are the three main parts of the circulatory system.

2SEE Boardqb-q1

What is the normal blood pressure of a healthy adult?

Ans.The normal blood pressure of a healthy adult is 120/80 mmHg.

3SEE Boardqb-q2

Name the pigment present in red blood cells.

Ans.Haemoglobin is the pigment present in red blood cells.

4SEE Boardqb-q3

What is serum?

Ans.Serum is the liquid part of plasma left after fibrinogen has been removed.

5SEE Boardqb-q4

Name the device used to measure blood pressure.

Ans.A sphygmomanometer is used to measure blood pressure.

6SEE Boardqb-q5

Which is the largest artery in the human body?

Ans.The aorta is the largest artery in the human body.

7SEE Boardqb-q6

What is the normal heart rate of a healthy adult at rest?

Ans.The normal heart rate of a healthy adult at rest is 60-100 beats per minute.

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Name the disease caused by deficiency of platelets.

Ans.Haemophilia is caused by a deficiency of platelets.

9SEE Boardqb-q8

What is angiogram?

Ans.An angiogram is the X-ray image formed during angiography, showing blood flow in blood vessels.

10SEE Boardqb-q9

Which valve lies between the left auricle and the left ventricle?

Ans.The bicuspid (mitral) valve lies between the left auricle and the left ventricle.

11SEE Boardqb-q10

What is hypertension?

Ans.Hypertension is a condition where blood pressure exceeds 140/90 mmHg.

12SEE Boardqb-q11

Which blood group is called the universal donor group?

Ans.Blood group O is the most common blood group and, because it lacks A and B antigens, is often referred to as a universal donor group.

Short Answer Questions

1SEE Boardqb-q12

What is plasma? Write any two functions of plasma.

Ans.Plasma is the pale-yellow, water-like liquid part of blood, making up 55% of blood volume. Two functions: it transports nutrients and wastes throughout the body, and it helps in clotting of blood through fibrinogen.

2SEE Boardqb-q13

Write the main function of white blood cells.

Ans.White blood cells fight against disease-causing germs that enter the body and destroy them, thereby protecting the body and increasing its immunity. They are called the soldiers of the human body.

3SEE Boardqb-q14

What is a heart attack?

Ans.A heart attack, or myocardial infarction, occurs when the flow of blood to the heart tissue is suddenly reduced or blocked, usually due to plaque or a clot in a coronary artery, so that the heart cannot function properly.

4SEE Boardqb-q15

What is pulse rate? Where can it be felt?

Ans.Pulse rate is the pressure exerted by flowing blood on the artery walls, which can be felt from outside the body. It can be felt at the radial artery on the wrist or at the carotid artery in the neck.

5SEE Boardqb-q16

Write any two risk factors of heart attack.

Ans.Two risk factors of heart attack are high blood pressure (hypertension) and consumption of tobacco products such as smoking.

6SEE Boardqb-q17

What is angioplasty?

Ans.Angioplasty (percutaneous coronary intervention) is a medical procedure to open a clogged coronary artery by inserting a catheter through a blood vessel and placing a stent to widen the artery and restore blood flow.

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What are the functions of platelets?

Ans.Platelets combine with fibrinogen to clot blood during cuts and injuries, preventing excessive blood loss.

8SEE Boardqb-q19

What is hyperuricemia?

Ans.Hyperuricemia is the condition caused by an increase in the level of uric acid in the blood, leading to problems such as joint pain and kidney stones.

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Write the pathway of pulmonary blood circulation.

Ans.In pulmonary circulation, deoxygenated blood flows from the right ventricle through the pulmonary artery to the lungs, where gas exchange occurs, and oxygenated blood returns to the left auricle through the pulmonary vein.

10SEE Boardqb-q21

What is the difference between heart rate and pulse rate in terms of measurement?

Ans.Heart rate is measured directly at the heart using a stethoscope, while pulse rate is felt at an artery such as the wrist or neck; in a healthy person, both values are normally equal.

Give Reason Questions

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Why is blood red in colour?

Ans.Blood is red because red blood cells contain a pigment called haemoglobin, which combines with oxygen to form oxy-haemoglobin, giving blood its red colour.

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Why are WBCs called the soldiers of the body?

Ans.WBCs are called the soldiers of the body because they fight against disease-causing germs that enter the body, destroy them, and increase the body's immunity.

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Why is the wall of the ventricle thicker than the wall of the auricle?

Ans.The wall of the ventricle is thicker because ventricles must pump blood with great pressure to different parts of the body or lungs, while auricles only receive blood, so they need less muscular strength.

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Why is the wall of the left ventricle thicker than the wall of the right ventricle?

Ans.The left ventricle pumps oxygenated blood to various organs throughout the whole body with great pressure, while the right ventricle pumps blood only up to the lungs, so the left ventricle needs a thicker, stronger wall.

5SEE Boardqb-q26

Why do arteries not have valves but veins have valves?

Ans.Arteries carry blood away from the heart under high pressure, so blood naturally flows in one direction without needing valves. Veins carry blood under low pressure, so they have valves at intervals to prevent the backward flow of blood.

6SEE Boardqb-q27

Why does a person with anaemia feel tired even after a short walk?

Ans.Anaemia is caused by a deficiency of red blood cells or haemoglobin, which reduces the oxygen-carrying capacity of blood. With less oxygen reaching the muscles and cells, the person feels tired quickly.

7SEE Boardqb-q28

Why should blood group be tested before blood transfusion?

Ans.Blood group must be tested before transfusion because if a patient is given blood that does not match their blood type, intra-venous clumping can occur in the patient's blood, which can be fatal.

8SEE Boardqb-q29

Why does blood coagulate slowly or not at all in a person with haemophilia?

Ans.In haemophilia, the number of platelets in the blood is abnormally low. Since platelets combine with fibrinogen to clot blood, a low platelet count means blood does not clot properly even in small wounds.

Differentiate Between

1SEE Boardqb-q30

Red blood cell and White blood cell

Red Blood Cell	White Blood Cell
Biconcave and without a nucleus.	No definite shape and has a nucleus.
Contains haemoglobin.	Does not contain haemoglobin.
Transports oxygen and carbon dioxide.	Fights germs and protects the body.

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Auricle and Ventricle

Auricle	Ventricle
Upper chamber of the heart; thin-walled.	Lower chamber of the heart; thick-walled.
Receives blood from the body or lungs.	Pumps blood out to the body or lungs.

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Artery and Vein

Artery	Vein
Carries blood away from the heart; no valves.	Carries blood towards the heart; has valves.
Thick, muscular wall.	Thin wall.

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Pulmonary blood circulation and Systemic blood circulation

Pulmonary Blood Circulation	Systemic Blood Circulation
Circulation of blood between heart and lungs.	Circulation of blood between heart and rest of the body.
Starts at right ventricle, ends at left auricle.	Starts at left ventricle, ends at right auricle.

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Systolic blood pressure and Diastolic blood pressure

Systolic Blood Pressure	Diastolic Blood Pressure
Upper reading; created during ventricular contraction.	Lower reading; created during ventricular relaxation.
Normal value about 90-130 mmHg.	Normal value about 60-90 mmHg.

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Anaemia and Haemophilia

Anaemia	Haemophilia
Caused by deficiency of red blood cells or haemoglobin.	Caused by deficiency of platelets.
Person feels tired even after a short walk.	Blood does not clot even in small cuts or wounds.

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Angiogram and Open heart surgery

Angiogram	Open Heart Surgery
An X-ray image showing blood flow, used for diagnosis.	A surgical procedure to treat a blocked coronary artery.
Non-surgical diagnostic technique.	Major surgical treatment (coronary artery bypass surgery).

8SEE Boardqb-q37

Platelets and White blood cells

Platelets	White Blood Cells
Smallest, round, non-nucleated blood cells.	Larger cells with a nucleus, no definite shape.
Function: help clot blood.	Function: fight infection and protect the body.

Long Answer Questions

1SEE Boardqb-q38

Describe the main parts of the human circulatory system.

Ans.The human circulatory system has three main parts.

2SEE Boardqb-q39

Explain the internal structure of the human heart with a labelled diagram.

Ans.The human heart has four chambers — right auricle, right ventricle, left auricle, and left ventricle — separated by a thick muscular septum that prevents mixing of oxygenated and deoxygenated blood.

The right auricle receives deoxygenated blood from the superior and inferior vena cava and passes it to the right ventricle through the tricuspid valve. The right ventricle pumps this blood to the lungs through the pulmonary artery via the pulmonary valve.

3SEE Boardqb-q40

Explain blood circulation in the human body with a diagram.

Ans.Blood circulation occurs in two ways.

Systemic circulation: Oxygenated blood from the left ventricle flows through the aorta and its branches to all parts of the body. After delivering oxygen and nutrients at the capillaries, deoxygenated blood returns through veins and the venacava to the right auricle.

4SEE Boardqb-q41

Explain the main causes (risk factors) of a heart attack.

Ans.A heart attack occurs mainly due to narrowing or blockage of the coronary artery caused by plaque (deposition of fat and cholesterol). The main risk factors are:

5SEE Boardqb-q42

Introduce angiography and explain its importance.

Ans.Angiography is a fluoroscopy X-ray technique used to detect blockages in blood vessels. Since normal X-ray images of blood vessels are not clearly visible, a special dye called a contrast medium is injected into the blood. This dye highlights the blood flow clearly, and the resulting image is called an angiogram.

Angiography is important because it helps doctors identify exactly where and how severely a coronary artery is blocked, so that appropriate treatment such as angioplasty, stenting, or bypass surgery can be planned quickly, which is essential since heart tissue is destroyed rapidly during a heart attack.

6SEE Boardqb-q43

Give a brief introduction to open-heart surgery (coronary artery bypass surgery).

Ans.Open-heart surgery, also called coronary artery bypass surgery, is an emergency surgical procedure used to treat a severely blocked coronary artery. A healthy blood vessel is taken from the leg area of the patient and used to create a new pathway (bypass graft) around the blocked part of the coronary artery. This allows nutrient- and oxygen-rich blood to reach the heart muscle again, restoring normal heart function.

7SEE Boardqb-q44

Explain the preventive measures of high blood pressure.

Ans.High blood pressure can be prevented and managed through the following measures:

8SEE Boardqb-q45

How are respiratory system, digestive system, and circulatory system interrelated? Explain with reasons.

Ans.These three systems work together to keep the body's cells supplied with what they need. The digestive system breaks down food into simple, soluble forms such as glucose. The circulatory system then transports this glucose, along with oxygen absorbed by the respiratory system from the lungs, to every cell of the body.

At the same time, the circulatory system carries carbon dioxide produced by cells back to the lungs (part of the respiratory system) to be exhaled, and carries other wastes to the excretory organs. Without the circulatory system, digested nutrients and inhaled oxygen could not reach the cells, and without the digestive and respiratory systems, the circulatory system would have nothing to transport.

Diagram-Based Questions

1SEE Boardqb-q46

Draw a neat and labelled diagram of the external structure of the human heart.

Ans.Label the following parts: superior vena cava, aorta, pulmonary vein, right auricle, left auricle, right ventricle, and left ventricle.

2SEE Boardqb-q47

Draw a neat and labelled diagram of the internal structure of the human heart.

Ans.Label the four chambers, the septum, the four valves (tricuspid, bicuspid/mitral, pulmonary, aortic), the aorta, pulmonary artery, pulmonary vein, superior and inferior venacava.

3SEE Boardqb-q48

Draw and label a diagram showing the types of blood vessels.

Ans.Draw a cross-section of an artery and a vein connected by a capillary, labelling tunica externa, tunica media, tunica interna, and the valve found in the vein.

4SEE Boardqb-q49

Draw a diagram to explain pulmonary and systemic blood circulation.

Ans.Draw the heart and lungs, showing the pathway: right ventricle → pulmonary artery → lungs → pulmonary vein → left auricle (pulmonary circulation), and left ventricle → aorta → body → venacava → right auricle (systemic circulation).

Application / Conceptual Questions

1SEE Boardqb-q50

Roshani's grandfather takes medicine orally for knee pain and feels better. How does the medicine reach the knee? Which body system and organ are mainly involved?

Ans.After the medicine is absorbed from the digestive system into the bloodstream, the circulatory system transports it through blood vessels to all parts of the body, including the knee. The circulatory system is mainly involved, and its main organ is the heart, which pumps the blood carrying the medicine to the required site.

2SEE Boardqb-q51

If the circulatory system were absent, could the medicine taken orally still reach the knee? Explain with reasons.

Ans.No. Without the circulatory system, there would be no blood vessels or pumping action to carry the absorbed medicine from the digestive system to the knee. The medicine would remain in the digestive tract or immediate surrounding tissue and would not be able to reach a distant body part like the knee.

3SEE Boardqb-q52

Saambhawi hurt her leg and the bleeding did not stop despite various efforts. What is the most likely reason?

Ans.The most likely reason is a lack of platelets in her blood. Since platelets combine with fibrinogen to clot blood, a low platelet count (as in haemophilia) means bleeding does not stop easily even with general treatment.

4SEE Boardqb-q53

Rasmila's grandfather feels swelling in joints and body pain after eating red meat, legumes, and fried foods. What is his problem?

Ans.He likely has a problem of high uric acid (hyperuricemia). Red meat, legumes, and fried foods are rich in purines, and excess purine intake raises uric acid levels in the blood, causing joint swelling and pain.

5SEE Boardqb-q54

A person feels thirstier, hungrier, dizzy, and sometimes faints, has frequent urination and blurred vision. What is the likely problem?

Ans.These are the classic symptoms of high blood glucose level in the blood, that is, diabetes (hyperglycemia).

6SEE Boardqb-q55

A person's blood pressure reading is 130/90 mmHg. What does this mean?

Ans.This means the person's systolic blood pressure (pressure during ventricular contraction) is 130 mmHg and diastolic blood pressure (pressure during ventricular relaxation) is 90 mmHg. Since the diastolic value is at the upper edge of the normal range, this reading indicates the person is at risk of developing hypertension and should monitor blood pressure regularly.

7SEE Boardqb-q56

Rohit's blood test for antigens shows clotting for A and B, but not for O and D. What is his blood group?

Ans.Since clotting occurs for antigen A and antigen B but not for antigen D (Rh factor), Rohit's blood group is AB negative (AB-).

8SEE Boardqb-q57

When Samip's WBC count is found to be much higher than normal, what symptoms may appear? Give a reason.

Ans.An abnormal increase in the number of white blood cells causes them to destroy other blood cells, resulting in a disease called leukemia (blood cancer). Symptoms may include fatigue, frequent infections, and easy bruising or bleeding, because normal blood cell function is disrupted.

9SEE Boardqb-q58

Harish's plasma shows a high level of fibrinogen at the time of a blood test. Does this affect his blood circulation? Explain.

Ans.Yes, it can affect blood circulation. Since fibrinogen helps in the clotting of blood, an abnormally high level increases the tendency of blood to clot more than necessary, which can form unwanted clots (thrombi) inside blood vessels and block normal blood flow, increasing the risk of conditions like heart attack or stroke.

10SEE Boardqb-q59

Study three injury cases: Person X (superficial injury, bleeding continuously, not stopped by general treatment); Person Y (deep injury, bleeding with high pressure, stopped by general treatment); Person Z (superficial injury, bled for a while and stopped). Which person suffers from haemophilia? In which person is the artery injured? Which injury, Y or Z, is more dangerous?

Ans.Person X suffers from haemophilia, because bleeding continued even from a superficial wound and did not stop with general treatment, indicating a platelet deficiency. Person Y has an injured artery, because bleeding occurred with high pressure — a sign of arterial bleeding due to high blood pressure in arteries. Between Y and Z, injury Y is more dangerous, because arterial bleeding under high pressure can cause rapid and severe blood loss compared to the mild bleeding seen in Z.

11SEE Boardqb-q60

Sarita saw an old man suffering from chest pain and rushed him to hospital. The initial examination suggested a heart problem. Which test would be most appropriate to identify his heart condition?

Ans.Angiography would be most appropriate. It uses a contrast medium injected into the blood to clearly show any blockage in the coronary arteries, helping doctors confirm and locate the exact site of blockage causing the heart problem, in addition to supporting tests such as ECG.

Additional SEE Practice

1SEE Boardqb-q61

Why is O the most common blood group in the world?

Ans.Blood group O occurs when the red blood cells carry neither antigen A nor antigen B on their surface. This combination is naturally the most frequently occurring pattern in human populations, making O the most common blood group worldwide.

2SEE Boardqb-q62

A patient's coronary artery is completely blocked and angioplasty equipment is unavailable at the local hospital. What treatment is likely given first?

Ans.When angiogram and angioplasty equipment are not available, doctors generally start treatment by using blood thinners, and then arrange to transfer the patient to a hospital equipped for angioplasty or bypass surgery as soon as possible.

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