A-V Valves Open; Semilunar Valves Closed. This is the first phase of the cardiac cycle. It is initiated by the P wave of the electrocardiogram (ECG), which represents electrical depolarization of the atria. Atrial depolarization initiates contraction of the atrial musculature.
Community Q&A. You can calculate age on Excel for a many applications by combining an undocumented function and the date format for cells. Microsoft Excel internally stores dates as serial numbers, which is the number of days a date is from Jan. 1, 1900.
This is far too broad a question to be answered fully. To see a list of all Excel functions just type the word 'function' into MS Excel Help and you will get a list of all of them. Basically a function is a device that does calculations behind the scenes and shows the result in a particular cell. Excel's DATEDIF Function If you regularly work with dates and times in Excel, then it is worth learning how some of Excel's date-related functions operate. 2  There are over 20 functions in this group, â¦. 3  How to Create a Spreadsheet in Excel A basic function of using Microsoft Excel is creating a spreadsheet.