A. The systolic blood pressure is the pressure that develops in arteries when the ventricles contract and the diastolic pressure develops when the ventricles relax. The normal range of blood pressure is 120/80 mm Hg. In hypertension, the blood pressure elevates to 130-140 mm Hg systolic and 90-100 mm Hg diastolic pressure.

Hypertension is caused due to an elevation in the pressure applied during the blood flow in the blood vessels. Blood pressure is expressed by two measurements, the systolic and diastolic pressures, which are the maximum and minimum pressures, respectively, in the arterial system. The systolic pressure occurs when the left ventricle is most contracted, the diastolic pressure occurs when the left ventricle is most relaxed prior to the next contraction. Normal blood pressure at rest is within the range of 100–140 millimeters mercury (mmHg) systolic and 60–90 mmHg diastolic. Hypertension is present if the blood pressure is persistently at or above 140/90 mmHg for most adults. 

Hypertension is the term for high blood pressure when blood pressure is higher than normal (normal 120/80 mmHg). In this measurement 120 mm Hg (millimeters of mercury pressure) is the systolic, or pumping pressure and 80 mm Hg is the diastolic, or resting pressure. If repeated checks of blood pressure of an individual are 140/90 (140 over 90) or higher, it shows hypertension. High blood pressure leads to heart diseases and also affects vital organs like brain and kidney.

S.A node called as pacemaker ,node of keith and  flack heart , brain of heart ,pulsation centre. 

When irregularity in the heart rhythm occurs, normal heart rhythm can be reared and maintained by surgically implanting an artificial pace maker, a device that sends out small electrical current to stimulate the heart to contract.

Alpha 2 receptors in the brain stem and in the periphery inhibit sympathetic activity and thus lower blood pressure.

Heart diseases can be caused due to a number of factors such as  age, gender, tobacco use, physical inactivity, excessive consumption of alcohol, unhealthy diet, obesity, family history of cardiovascular disease, hypertension, diabetics, high cholesterol levels , psychosocial factors and pollution, However, a patient with any form of heart disease should avoid cream as intake of dietary trans fat tends to perturb  the body's ability to metabolize the essential fatty acids which lead to changes in the  phospholipid fatty acid composition of the main artery of the heart. This tends to increase the risk of coronary heart disease.

Answer is option C i.e. "Lack of iron"
Cardiovascular diseases (CVD) are a group of disorders of the heart and blood vessels (e.g. coronary heart disease, cerebrovascular disease,congenital heart disease, etc.). The most important risk factors of CVD are hypertension (raised blood pressure), diabetes (raised blood glucose), hyperlipidaemia (raised blood lipids), unhealthy diet, obesity (overweight), tobacco use, smoking and harmful use of alcohol.
Also, lack of iron leads to anemia or lack of hemoglobin production and not CVD.

Chylomicron remnants, VLDL, IDL, LDL, and Lp (a) are all pro-atherogenic, while HDL is anti-atherogenic.

Congenital heart disease refers to the problem in the structure of the heart that is present at birth. It can be related to the wall of the heart, the valves of the heart and the arteries and veins associated with the heart. Patent Foramen Ovale is the example of congenital heart disease in which the septal wall between the right and the left atrium is not formed.

• Hair loss can be the result of heredity, hormonal changes, medical conditions or medications. Anyone can experience hair loss, but it's more common in men.
•  Hereditary hair loss with age is the most common cause of baldness. 
• Hair follicles thrive on nutrients and oxygen supplied by the blood capillaries. Increased blood circulation to the scalp encourages the scalp to increase hair growth throughout the entire head.
•  A lack of oxygen affects all cells, including the hair cells and can cause premature hair thinning and hair loss. 
• Hence,  hair loss is more in old age is due to Reduction of blood supply.
• So, the correct answer is 'Reduction of blood supply'.

. If an Rh-positive man marries an Rh-negative woman, then the first foetus (and foetuses thereafter) will be Rh-positive. In this case, the Rh-positive antigen from the foetus will enter into the bloodstream of the mother and there will be the formation of anti-Rh antibodies in mother’s body. During her second pregnancy, these antibodies will attach the red blood cells of the Rh-positive foetus and coagulate the blood, resulting in severe complications. These complications arising due to Rh incompatibility are called erythroblastosis foetalis.

Atherosclerosis is a disease condition of the arteries, where the lumen of the arteries gets narrow because of deposition of lipids in the endothelial and mesothelial layers of the blood vessel. Prolonged deposition of lipids leads to hardening of the walls of these arteries and blood flow through the arteries is reduced. Thus, the correct answer is option B.

The cardiac sphincter separates the esophagus from the stomach. When cardiac sphincter fails to close and leads to regurgitation of food and gastric acid into the esophagus from stomach it leads to heat burn. The symptoms of heat burn include a chronic cough, burning feeling in the chest, chest pain and burning at the back of the throat.

The events of a heart attack can be put in a sequence of I, IV, II, III.

A heart attack occurs when one of the heart's coronary arteries is blocked suddenly or has extremely slow blood flow. A heart attack also is called a myocardial infarction. The usual cause of sudden blockage in a coronary artery is the formation of a blood clot.

• The symptoms of myocardial infarction include heaviness and severe pain in the chest and neck region, lower jaw, left arm and left shoulder. 
• Angina pectoris has symptoms of acute chest pain when not enough oxygen is reaching the heart muscle. 
• Atherosclerosis affects the vessels that supply blood to the heart muscle which is caused by deposits of calcium, fat, cholesterol and fibrous tissues making the lumen of arteries narrower. 
• Arteriosclerosis show symptoms like chest pain or pressure, sudden arm or leg weakness or numbness, slurred speech, high blood pressure, etc. 
• So, the correct option is "Myocardial infarction".

Heart failure means the state of heart, when it is not pumping blood effectively enough to meet the needs of the body. It is sometimes called congestive heart failure because congestion of the lungs is one of the main symptoms of this disease. Heart failure is not the same as cardiac arrest (when the heart stops beating) or a heart attack (when the heart muscle is suddenly damaged by an inadequate blood supply).

Carboxyhemoglobin (COHb) is a stable complex of carbon monoxide and hemoglobin. It forms in red blood cells upon contact with carbon monoxide (CO). Large quantities of CO hinders the ability of Hb to deliver oxygen to the body. CO is produced in normal metabolism and is also a common chemical in smoke and industry and vehicular exhaust. Also, tobacco smoking (through carbon monoxide inhalation) raises the blood levels of COHb several times from its normal concentrations.

Angina pectoris - It is the sensation of chest pain as a result of myocardial ischemia, caused by an imbalance between myocardial blood supply and oxygen demand. It is a common symptom among patients with coronary artery disease (CAD).
Myocardial infarction - commonly known as a heart attack, occurs when blood stops flowing properly to a part of the heart, and the heart muscle is injured because it is not receiving enough oxygen. Usually, this is because one of the coronary arteries that supplies blood to the heart develops a blockage due to an unstable buildup of white blood cells, cholesterol and fat.
Cardiomegaly - is a medical condition, which refers to the enlargement of heart.

Carbon monoxide is an atmospheric pollutant present in vehicular exhaust and cigarette smoke. Carbon monoxide is a poisonous gas and reduces oxygen carrying capacity of blood. One molecule of hemoglobin combines with four molecules of carbon monoxide to form carboxyhemoglobin. The colour of carboxyhemoglobin is cherry red. 

Erythroblastosis fetalis is a hemolytic anemia in the fetus caused by the transplacental transmission of maternal antibodies to the fetal RBCs. In this alloimmune condition that develops in the fetus, the IgG molecules produced by the mother pass through the placenta and so is because of incompatibility.
Jaundice is caused because of the excess of bilirubin in the blood.
Therefore, the correct answer is option D.

Tachycardia refers to an abnormally fast resting heart rate - usually at least 100 beats per minute. The threshold of a normal heart rate (pulse) is generally based on the person's age. 

Among men, the 5 most common sites of cancer diagnosed are lung (pulmonary), prostate, colorectum, stomach and liver cancer.
Therefore, the correct answer is option D.

• Cholesterol and other fats travel in the bloodstream in the form of lipoproteins.
  
• Saturated fats in the diet raise the level of LDL (low-density lipoprotein) cholesterol in the blood.
• This LDL cholesterol is called bad cholesterol.
• It forms a plaque-like substance on the walls of arteries which causes the narrowing of arteries.
• Thus, it blocks the natural flow of blood and causes a severe risk for heart attack and stroke. So, the correct answer is 'Narrowing arteries by fat deposition'.

Carbon monoxide is a harmful gas that combines with haemoglobin to form a stable compound. It displaces the oxygen that is normally carried by the haemoglobin and reduces the oxygen-carrying ability of the blood by reducing the concentration of free hemoglobin in the blood. 

When carbon monoxide (CO) is inhaled, it combines with the haemoglobin to form a stable compound called as carboxyhemoglobin (COHb). CO displaces oxygen attached to the carrier molecule, haemoglobin. The COHb bond is over 200 times stronger than oxygen's bond with haemoglobin. The strong COHb bond makes it difficult for the body to eliminate CO from the blood. At 30-50% COHb symptoms are nausea, severe headaches, dizziness and increased pulse and respiration. COHb levels over 50% cause progressive symptoms proceeding to loss of consciousness, collapse, convulsions, coma and finally death.

Carbon monoxide is a light and toxic gas which impairs the process of respiration. The affinity of the carbon monoxide towards haemoglobin is more compared to the affinity towards oxygen which results in the binding of carbon monoxide with haemoglobin, forming carboxyhemoglobin. There are very less sites for oxygen binding and transport of the oxygen is reduced in the body which is known as carbon monoxide poisoning. Due to lack of oxygen, the process of respiration is hampered.

Carbon monoxide is a harmful gas that combines with haemoglobin to form a stable compound. It displaces the oxygen that is normally carried by the haemoglobin and reduces the oxygen-carrying ability of the blood. The affinity between hemoglobin and carbon monoxide is approximately 200 times greater than the affinity between hemoglobin and oxygen, so hemoglobin binds to carbon monoxide in preference to oxygen.

In coronary thrombosis, blood clotting occurs which becomes fatal. Physicians normally prescribe such medicines which prevent blood clotting or dissolve the clots that are formed.

The hemoglobin have more affinity towards the carbon monoxide rather than the oxygen. When the air is inhaled and there is presence of carbon monoxide, the hemoglobin protein binds to the carbon monoxide. This results in the formation of complex called as carboxyhemoglobin. This is the condition in which there is reduction in the supply of oxygen to the tissues which might lead to death.

The first human heart transplant was performed on 3rd December, 1967 by a team of 30 doctors headed by Prof. Christian Barnard on 55 years old Louis Washkansky at the Groote Schurr Hospital, Cape Town, South Africa. Inspite of the operation by a leading' surgeon WasEKansKy died on @Ist December, 1967.

Tachycardia is a condition, when the heart rate exceeds the normal range in resting condition. Generally, when the heart rate (human) crosses more than 100 beats per minute in the resting state, then the person is said to be suffering from tachycardia. It can occur in fever, hypovolemia and hyperthyroidism.

Bradycardia is an abnormality of the heart where an individual has the slow heart rate. The normal heart rate for an adult human being at rest is 72 beats per minute. In bradycardia, the heart rate is less than 60 beats per minute in adults. Shortage of oxygenated blood due to infection of lungs is the major cause of bradycardia. The heart is unable to get the sufficient amount of oxygenated blood from the lungs. It turns fatal and may cause cardiac arrest.

Haemophilia is a group of hereditary disease that impair the body's ability to control blood clotting or coagulation. Britain's Queen Victoria, through two of her five daughters, passed this mutation to various royal families across the continents, including the royal houses of Spain, Germany and Russia. Victoria's son also suffered from this disease. For this reason, Hemophilia is also called as 'the royal disease'.
Thus, the correct answer is option (D), 'Both (B) and (C)'.

Sickle cell anemia is the serious disorder in which the body makes sickle-shaped red blood cells. RBCs contain hemoglobin which carries oxygen from lungs to rest of the body. Sickle cells contain abnormal hemoglobin called sickle hemoglobin.
Thus, the correct answer is option (C), 'A genetically determined defect of haemoglobin synthesis'.

Atherosclerosis is not related to the bone disorder. It is a condition related to arteries. Atherosclerosis is a condition where the arteries become narrowed and hardened due to a buildup of cholesterol around the artery wall. Arthritis, rickets and osteoporosis are the diseases related to the bone disorder. 

Radioactive $I^{131}$ gets concentrated in the thyroid gland like ordinary iodine ($I^{127}$). Radioactive $Sr^{90}$ is mistaken for calcium and enters bones to cause bone cancer. It also causes damage to WBCs, bone marrow, spleen, lymph nodes, etc. It impairs eyesight and produces sterility, skin cancer and lung tumors.
Thus, the correct answer is option (C), '$Strontium^{90}$'.

The Christmas disease is nothing but the Haemophilia B. It is a blood clotting disorder caused by a mutation of the factor IX gene, leading to a deficiency of factor IX . It is called as Christmas disease, as it is named after Stephen Christmas, the first patient described with this disease.
Therefore, the correct answer is option A.

Erythropoiesis is the process, which produces red blood cells. It is stimulated by decreased oxygen in circulation, which is detected by kidneys which then secretes the hormone erythopoietin. This hormone stimulates proliferation and differentiation of the red blood cell precursors. When there is anemia, there is low oxygen tension in the body. Because of this, there is a rise in the cell count due to liberation of erythropoietin.
Thus, the correct answer is option (C), 'Erythropoietin'.

Haemophilia is a group of hereditary disease, that impair the body's ability to control blood clotting or coagulation.
Thus, the correct answer is option (C), 'Haemophilia'.

Cardiopulmonary bypass (CPB) is a technique that temporarily takes over the function of the heart and lungs during surgery, maintaining the circulation of blood and the oxygen content of the body. The CPB pump itself is often referred to as a heartlung machine or "the pump". A CT or CAT scan is a diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, organs, and blood vessels. CT scans are more detailed than standard X-rays.

Arteriosclerosis, thickening and hardening of the arteries, is a condition in which plaque builds up inside the arteries. Plaque is made of cholesterol, fatty substances, cellular waste products, calcium and fibrin (a clotting material in the blood). Atherosclerosis is a type of arteriosclerosis. Arteriosclerosis is a general term for the thickening and hardening of arteries.  

A petechia is a small (1 - 2 mm) red or purple spot on the skin, caused by a minor haemorrhage (broken capillary blood vessels). The flat round red spots formed under the skin due to bleeding are known as petechiae. They are red due to the leakage of blood from the capillaries.

Patent ductus arteriosus (PDA) is a congenital disorder in the heart, wherein a neonate's ductus arteriosus fails to close after birth. 

The red blood cells contain hemoglobin and each red blood cell contains nearly 280 million hemoglobin molecules. The hemoglobin molecules transport oxygen from the lungs to the tissues and also transports CO$ _2$ from the tissues to the lungs. However, the affinity displayed by hemoglobin molecules for carbon monoxide is many times greater than oxygen. The presence of even very low levels of carbon monoxide has a profound effect on oxygen transport of the blood. Moreover, the binding of carbon monoxide to hemoglobin is irreversible.

Minimum concentration and pressure of CO in alveoli of lungs that would be dangerous to man is about 1 %, 0-7 mm Hg.
Carbon monoxide from alveolar air diffuses into the blood, competes with oxygen for binding sites on hemoglobin molecules. As carbon monoxide binds to hemoglobin with more affinity than oxygen to form a more stable compound called as carboxyhaemoglobin. This prevents the carriage of oxygen to the blood, and hence to tissues, muscles and all other organs (heart, brain, kidney, liver etc.) and thus can even lead to death. Carbon monoxide poisoning can occur acutely with smoke intoxication, or over a period of time, as in cigarette smoking.

Haemophilia is a group of hereditary genetic disorders that impair the body's ability to control blood clotting, which is used to stop bleeding when a blood vessel is broken.
It is recessive (not dominant) sex-linked, X-chromosome disorder.
Thus, the correct answer is option (B), 'It is a dominant disease'.

Splenomegaly is a condition of enlargement of the spleen. This is a condition of overload that suggests overload. It is called so because as the spleen grows its main function is to destroy or remove the old RBC and abnormal RBC and also prevents the infections by producing white blood cells. 
So in the condition of splenomegaly the removal of RBC will be impaired.

As the body fluids and tissues are good conductors of electricity, the electrical activity within the heart can be detected by attaching electrodes to the surface of the body. The pattern of electrical activity may be displayed on an oscilloscope screen or traced on paper. The apparatus used is an electrocardiograph and the tracing is an electrocardiogram (ECG). The normal ECG tracing shows five waves which, by convention, have been named P, Q, R, S and T. The standard ECG originates from the SA node and is known as sinus rhythm. The rate of sinus rhythm is 60 to 100 beats per minute. A faster heart rate is called tachycardia and a slower heart rate, bradycardia. Acetylcholine is a neurotransmitter of parasympathetic system of nerves and slows down heart rate.

Erythroblastosis fetalis is hemolytic anemia in the fetus caused by transplacental transmission of maternal antibodies to the fetal RBCs. The disorder usually results from incompatibility between the maternal and fetal blood groups, often Rh antigens. Erythroblastosis fetalis classically results from Rh incompatibility, which may develop when a woman with Rh-negative blood is impregnated by a man with Rh-positive blood and conceives a fetus with Rh-positive blood.
Thus, the correct answer is option (B), 'Disadjustment of Rh factor'.