<prompt> The duration of atrial systole is0.80 second0.57 second0.11 second0.44 second  <response>: The duration of each of the hea sounds is slightly more than 0.10 second, with the first sound about 0.14 second and the second about 0.11 second. Ref: Guyton and Hall textbook of medical physiology 13th edition. Page: 119 