<prompt> Shape of the aerial pulse is influenced by:Viscosity of bloodVelocity of bloodAerial wall expansionCross sectional area of aery.  <response>: C i.e. Aerial wall expansionThe blood forced into the aoa during systole not only moves the blood in the vessels forward but also sets up a pressure wave that travel along the aeries. The pressure wave expends the aerial wallQ as it travels, and expansion is palpable as the pulse. 