The Circulatory System

Provide immunity

Reason — WBCs provide immunity by destroying the disease causing germs and producing antibodies.
RBCs transport oxygen. Platelets help in clotting of blood. Blood cells do not provide storage of food.

Narrow tube made up of endothelium only

Reason — Blood capillary is narrow blood vessel whose walls have a single layer of cells called endothelium.
Blood capillaries are not broad. They are the smallest and narrowest blood vessels in the body, so narrow that blood cells pass through them one at a time. Arteries have thick, elastic, muscular walls and high-pressure blood flow. Capillaries are very thin and are not arteries. Veins have thinner walls than arteries and wide lumen. Capillaries do not have a large lumen; they are extremely narrow.

RBCs

Reason — RBCs have no nucleus because they need space for haemoglobin to carry more oxygen.
White blood cells do have a nucleus. Liver cells are ordinary body cells and also have a nucleus.

Pulmonary artery

Reason — Pulmonary artery leaves the right ventricle of the heart carrying the deoxygenated blood to the lungs for oxygenation.
Hepatic artery carries oxygenated blood to the liver. Aorta carries oxygenated blood from the heart to the whole body. Renal artery carries oxygenated blood to the kidneys.

Blood pressure

Reason — Sphygmomanometer is an instrument which is used to find out blood pressure of the body.
Pulse rate is measured by feeling the pulse or using a pulse monitor. Heartbeat is the action of the heart; it is not directly measured by this instrument. Brain activity measured using an EEG (Electroencephalogram).

Oxygenated blood

Reason — Oxygenated blood from the lungs returns to the left auricle via pulmonary veins.
Deoxygenated blood is carried by the pulmonary artery (not vein). Glucose-rich blood is not specifically related to this vessel. CO₂ laden blood is carried to the lungs by the pulmonary artery.

Sodium chloride

Reason — The blood tastes saltish due to dissolved minerals like sodium chloride.
Potassium chloride is present in blood but not the main reason for saltish taste. Ammonium nitrate is not a natural component of blood. Sodium nitrate is not present in blood in significant amount.

Heart

Reason — The heart is the main pumping organ of the human cardiovascular system. It pumps blood through the blood vessels to all parts of the body. Therefore, it is an organ of the cardiovascular system.
Liver is digestive organ involved in metabolism and detoxification. Kidney is part of the excretory system, filters waste from blood. Lung is part of the respiratory system, helps in gas exchange.

Iron + Proteins

Reason — Haemoglobin is an iron and protein compound found within RBCs. It acts as the "oxygen-carrier".
Iodine is related to thyroid hormones, not haemoglobin. Amino acids form proteins, but haemoglobin is specifically a protein with iron-containing haem groups. Globin itself is already a protein; haemoglobin is globin + haem (iron-containing part).

Vena cavae

Reason — The Superior Vena Cava and the Inferior Vena Cava brings deoxygenated blood from the upper and lower parts of the body to the right auricle of the heart.
Pulmonary artery carries deoxygenated blood, but from the heart to the lungs (not to the heart). Aorta carries oxygenated blood from the heart to the body. Pulmonary vein carries oxygenated blood from the lungs to the heart.

Both A and R are true and R is the correct explanation of A.

Reason — A is true as blood transports nutrients, oxygen, carbon dioxide, hormones, and waste materials throughout the body. Blood circulation is generally unidirectional because of the pumping action of the heart and the presence of valves.
R is true as unidirectional flow ensures that oxygenated blood and deoxygenated blood are delivered to the correct organs efficiently without mixing.

Therefore, Both A and R are true and R is the correct explanation of A is the correct option.

A is false but R is true.

Reason — A is false as arteries do carry blood away from the heart, but they have thick, elastic, muscular walls and narrow lumen.
R is true as arteries usually carry oxygenated blood from the heart to body tissues to provide oxygen.

Therefore, A is false but R is true is the correct option.

A is false but R is true.

Reason — A is false as the right side of the heart receives deoxygenated blood from the body and sends it to the lungs. The left side of the heart receives oxygenated blood from the lungs and pumps it to the whole body.
R is true as oxygenated and deoxygenated blood do not mix in the human heart because the heart has separate chambers for each type of blood.

Therefore, A is false but R is true is the correct option.

Both A and R are true and R is the correct explanation of A.

Reason — A is true as pulmonary circulation involves the movement of blood only between the heart and the lungs.
R is true as in pulmonary circulation, deoxygenated blood goes from the heart to the lungs through the pulmonary artery. In the lungs, the blood receives oxygen. Oxygenated blood then returns to the heart through the pulmonary veins.

Therefore, Both A and R are true and R is the correct explanation of A is the correct option.

(a) Haemoglobin
(b) Ventricles
(c) Nutrients, Proteins, waste products and Hormones
(d) Pulmonary
(e) Sphygmomanometer
(f) Right Auricle
(g) Left Auricle
(h) Aorta
(i) Pulmonary

(i) Odd one — Leukoplasts
Category of the remaining terms — Corpuscles (Blood cells)

(ii) Odd one — Atria
Category of the remaining terms — Blood vessels

(iii) Odd one — Kidney
Category of the remaining terms — Parts of Circulatory System

(iv) Odd one — Haemoglobin
Category of the remaining terms — Corpuscles (Blood cells)

(v) Odd one — Diaphragm
Category of the remaining terms — Parts of the heart

Difference between Platelets and WBCs:

Difference between Pulmonary artery and Pulmonary vein:

Difference between Vena cava and Aorta:

Difference between RBC and WBC:

Three differences between an Artery and a Vein are:

Blood is a red coloured fluid which consists of two parts:

1. Liquid part — The liquid part of the blood is called Plasma. Plasma is yellow in colour. 90% of Plasma is water and the remaining 10% consists of dissolved proteins, nutrients, waste product and hormones.
2. Cellular part — The cellular part of the blood is called Corpuscles. The corpuscles are of three types:
   1. Red Blood Cells (RBCs) — RBCs are also called as Erythrocytes. They carry oxygen from lungs to all the body tissues and cells and remove carbon dioxide produced in the cells and carry it back to the lungs. RBCs are circular or biconcave disc shaped. A mature RBC does not contain nucleus. Haemoglobin present in RBCs helps in transport of oxygen and gives them the red colour.
   2. White Blood Cells (WBCs) — WBCs are also called Leukocytes. They are colourless and lack haemoglobin. They are larger than RBCs and have a distinct oval or lobed nucleus. WBCs provide immunity by destroying the disease causing germs and producing antibodies
   3. Platelets — The platelets are also called Thrombocytes. They are round in shape and the smallest in size. They help in the clotting of blood which prevents excessive blood loss and direct entry of disease causing germs into the blood through cuts and wounds.

Haemoglobin is an iron and protein compound present in the Red Blood Cells (RBCs). It acts as the Oxygen carrier as it binds with Oxygen transporting it to all the body tissues and cells. It also helps to remove carbon dioxide produced in the cells and carry it back to the lungs.

Blood becomes oxygenated in the lungs.

The left side of the heart contains oxygenated blood.

Dengue fever is one such disease in which the number of platelets reduces to 25,000 - 30,000 per cu mm of blood. The major symptoms of dengue are high fever, rashes or red spots on body, vomiting, pain in abdomen or back of the eyes and muscles.

(i) Blood, Blood vessels and Heart
(ii) Arteries, Veins and Capillaries
(iii) Erythrocytes (RBCs), Leukocytes (WBCs), Thrombocytes (Platelets)
(iv) Pulmonary Circulation and Systemic Circulation
(v) A, B, AB, and O

(i) Haemoglobin — Haemoglobin is an iron and protein compound that is found within the Red Blood cells. It acts as the "oxygen-carrier".

(ii) Capillaries — Capillaries are the terminal branches of an artery, which rejoin to form a vein.

(iii) Aorta — The aorta is the largest artery in the body and carries oxygenated blood from the left ventricle to all parts of the body through its branches.

(iv) Universal donor — A person with O blood group can give blood to a person of any blood type and is therefore called a universal donor.

(v) Blood pressure — The pressure exerted by the blood on the walls of the arteries while flowing through them is called blood pressure.

(i) Karl Landsteiner identified the different types of blood groups.
(ii) A faster heart beat is usually an indication of hypertension.
(iii) WBCs produce special substances called antibodies.
(iv) Erythrocytes contain haemoglobin.
(v) Veins possess valves.

(i) Erythrocytes contain an iron and protein compound called Haemoglobin that acts as the "oxygen-carrier".

(ii) The Thrombocytes help in the clotting of blood which prevents excessive blood loss and direct entry of disease causing germs into the blood through cuts and open wounds.

(iii) Arteries are crucial blood vessels that carry the blood away from the heart (oxygenated blood) to different parts of the body.

(iv) The vena cava's primary role is to return deoxygenated blood from the body back to the heart.

(v) The heart, acting as a pump, pushes and receives the blood to and from the whole body through the blood vessels.

The two diseases in which the number of platelets in the human body are lowered to a great extent are:

1. Purpura
2. Dengue.

The three kinds of blood vessels found in human beings are Arteries, Veins and Capillaries.

Below diagram shows the differences between Artery, Vein and Capillaries:

Difference between White blood cells and Red blood cells:

These blood vessels seen on the outside of the hands are Veins. Usually, arteries are deeply placed in the body whereas Veins are placed more superficially.

The marked parts are:

1. Left pulmonary artery
2. Superior vena cava
3. Left pulmonary vein
4. Right auricle
5. Left ventricle

a) Deoxygenated blood is carried by the blood vessel marked 2 (Superior vena cava).

b) Aorta

c) Left auricle

Differences between arteries and veins on the basis of their structure:

Differences between atria and ventricles on the basis of their location in the heart:

Differences between Blood groups 'AB' and 'O' on the basis of antigens:

Differences between pulmonary and systemic circulation on the basis of direction of blood flow:

Differences between pulmonary artery and pulmonary vein on the basis of the kind of blood they carry:

(i) The normal heart rate of an adult at average is about 72 beats per minute.

(ii) A thumping or fast-beating heart will make the pulse rate increase. The pulse will feel faster and stronger than normal.

(iii) The pulse rate is measured by gently pressing the finger over an artery on the wrist along the side of the thumb.

(iv) One suitable advice for Kritika before going to a doctor is that she should take proper rest and avoid heavy physical activities or excessive running until she is examined by a doctor.