URL：https://s3-us-west-2.amazonaws.com/courses-images/wp-content/uploads/sites/1940/2017/05/29213842/hjbdduukq1619wcos44a.png
掲載元：https://med.libretexts.org/Courses/James_Madison_University/AandP_for_STEM_Educators/15:_Cardiovascular_System-_The_Heart/15.04:_Physiology_of_the_Heart/15.4A:_Electrical_Events
