Tag: blood circulatory system of human

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'.