Functioning of Human Heart MCQ - Practice Questions with Answers

 Functioning of Human heart

• The heart regularly and rhythmically contracts and relaxes at short intervals throughout life without pause and fatigue
• The heart functions by collecting blood through both the atria and then distributing it through the ventricles
• The action of the heart is a summation of contractions and relaxations of the atria and ventricles.
• The contraction of the heart is called systole whereas the relaxation of heart is referred as a diastole
• The atria and ventricles of the heart contract alternately.
• A single contraction of heart followed by relaxation of heart constitutes a heart beat
• Contraction of atria is initiated and activated by the SA node which then transmits these waves of contraction across the walls of atria through muscle fibres.
• When this wave of contraction originating from SA Node reaches the AV node, it gets  stimulated.
• The excitatory impulses are rapidly transmitted from AV node to all parts of the ventricles via bundle of His and Purkinje fibres
• These impulses causes contraction of ventricles simultaneously
• The ventricles force blood through a long system of arteries and hence exert great pressure on the blood