Day:Night Heart Rate Image (IMAGE) UK Research and Innovation Caption Heart clocks regulate the daily variation in heart rate - Each heart cell has a clock that regulates the frequency of firing rate between day and night. This helps the heart to beat faster during the day and to sustain daily activities. Credit Copyright MRC LMB Usage Restrictions External and Third Party Use of MRC Laboratory of Molecular Biology (LMB)Videos: Terms and Conditions of Use •You may only use this video for non-commercial use, e.g. not for advertising/marketingpurposes. •You may not use the video to promote any organisation of any sort, or in any way that could suggest the LMB’s approval or support. •You may not use the video in a defamatory context, or in any way that could harm the reputation of the person(s) depicted inthe video, or the LMB. •You may use a section of the video, but you may not alter or modify the video in any other way without permission fromthe LMB. •You must properly credit the ‘MRC Laboratory of Molecular Biology’(or ‘MRC LMB’ if space is tight)as thecopyright holder of the video, wherever you reproduce the video, or any work deriving from the video.LMB News Team, 2019 License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.