<prompt> awave in JVP is seen in-Will be large when atria contracts against resistanceFilling of ventriclesIt is followed by V wavesin inspiration  <response>: The a wave is due to atrial systole.some blood regurgitates into great veins when the atria contract.In addition,venous flow stops, the resultant rise in venous pressure contributes to a wave. Ganong;s Reviw of medical physiology,23rd edition,pg no.512 