'a'wave in JVP is seen in-: (A) Will be large when atria contracts against resistance, (B) Filling of ventricles, (C) It is followed by "V" waves, (D) in inspiration
Answer is A. 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)