Assertion : Blood coagulate in uninjured blood vessels.
Reason : Uninjured blood vessels release an anticoagulant heparin.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false.
D.
If both assertion and reason are false.
When a blood vessel gets injured, blood platelets get clumped at the injured spot and release certain chemicals called platelet factors, which promote blood coagulation.
Injured tissues or platelets also release coagulation promoting substances called thromboplastins which help in the formation of an enzyme prothrombinase. This enzyme activates inactive protein prothrombin to active thrombin which further promotes the coagulation process.
Blood normally contains an anticoagulant heparin which is released from mast cell granules that prevents the activation of prothrombin in uninjured blood vessels. Blood also contains antithrombin which inhibits any thrombin formed accidentally. Moreover, uninjured tissues do not release thromboplastins, hence blood does not coagulate in uninjured blood vessels.
Which one of the following is a matching pair
Lubb - Sharp closure of AV valves at the beginning of ventricular systole
Dup - Sudden opening of semilunar valves at the beginning of ventricular diastole
Pulsation of the radial artery - Valves in the blood vessels
Initiation of the heart beat - Purkinje fibres
The component of blood which prevents its coagulation in the blood vessels is
Haemoglobin
Plasma
Thrombin
Heparin
Thickening of arteries due to cholesterol deposition is
arteriosclerosis
rheumatic heart
blood pressure
cardiac arrest
Assertion : Smaller the organism higher is the rate of metabolism per gram weight.
Reason : The heart rate of a six month old baby is much lower than that of an old person.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
The given figure shows an angiogram of the coronary blood vessel. Which one of the following statements correctly describes, what is being done
It is coronary artery which has a cancerous growth that is being removed.
It is coronary artery which is blocked by a plaque and the same is being cracked.
It is coronary vein in which the defective valves are being opened.
It is coronary vein blocked by a parasite (blood fluke) that is being removed.
Formation of non-functional methaemoglobin causes blue-baby syndrome. This is due to
excess of arsenic concentration in drinking water
excess of nitrates in drinking water
deficiency of iron in food
increased methane content in the atmosphere
In which one of the following pairs the two items mean one and the same thing
Malleus - anvil
SA node - pacemaker
Leucocytes - lymphocytes
Haemophilia - blood cancer
Assertion : Persons suffering from haemophilia fail to produce blood clotting factor VIII.
Reason : Prothrombin producing platelets in such persons are found in very low concentration
If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion
If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion
If Assertion is true but Reason is false
If both Assertion and Reason are false
Which one of the following is a matching pair of a certain body feature and its value/count in a normal human adult?
Urea- 5 - 10 mg/100 ml of blood
Blood sugar (fasting) - 80 - 100 mg/100 ml
Total blood volume - 3 - 4 litres
ESR in Wintrobe method - 9 -15 mm in males and 20 - 34 mm in females
