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
A.
Lubb - sharp closure of AV valves at the beginning of ventricular systole
The gradually increasing contraction of ventricular muscles during systole first causes the closure of bicupsid and tricupsid valves (AV valves), producing a low- pitched "lubb" sound. Later, it causes the opening of the semilunar valves of systemic and pulmonary aorta. At the end of ventricular systole, semilunar valves shut, producing the second, louder heart sound, the "dup". Thus, each heart beat is accompained by a "lubb- dup" sound.
Which proteolytic enzyme induces lysis of fibrin during fibrinolysis ?
Fibrin
Thrombin
Plasmin
Platelet factor-VII
'P' wave of ECG occurs before the:
onset of ventricular ejection
end of atrial contraction
begining of atrial contraction
none of the above
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 higher than that of an old person.
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 statement but Reason is false
If both Assertion and Reason are false statements
The first heart sound is produced when :
diastole begins
semilunar valve close quickly
interventricular pressure decreases
bicuspid and tricuspid valve close quickly
Which of the following layer of heart wall consists of cardiac muscles ?
Endocardium
Myocardium
Epicardium
All of these
Blood pressure increases and heart rate decreases in response to :
exercise
haemorrhage
exposure to high altitude
increased intracranial pressure
In which form CO2 is mostly carried by blood
bicarbonate
carbonic acid
Carbamino compound
Carboxyhaemoglobin
