Read the assertion and reason carefully to mark the correct option out of the options given below:
(a) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
(b) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
(c) If the assertion is true but the reason is false
(d) If both the assertion and reason are false
(e) If the assertion is false but reason is true
Assertion : An artifical pacemaker can replace the sinoatrial node of heart.
Reason : This is because, an artifical pacemaker is capable of stimulating the heart electrically to maintain its beats.

Answer

A

Explanation

An artificial pacemaker is a therapeutic instrument which is implanted in the heart of patients to generate the heart beat. A pacemaker is used when the normal heart rate of 72-80 drops down to abnormally low levels like 30-40 due to diseases or operations and threatens the life of the patient. Sometime the SA node may become damaged or defective. if then fails to generate cardiac impulses at the normal rate. the heart beats become abnormally slow and irregular and venticles fail to pump the required amount of blood. this is remedied by the chest of the patient. the artificial pacemaker stimulates the heart electrically at regular intervals to maintain its beats. thus it replaces th SA node as the originator of the cardiac impulse.