房室延搁
房室交界区的传导性很低,传导速度缓慢(仅为0.02m/s),兴奋通过房室交界区耗时约0.1s,称为房室延搁。房室延搁的存在具有重要生理意义,它保证心室的收缩发生在心房收缩完毕之后,有利于心室的充盈和射血。
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧