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.
The Microsoft Excel COUNT function counts the number of cells that contain numbers as well as the number of arguments that contain numbers. The COUNT function is a built-in function in Excel that is categorized as a Statistical Function. It can be used as a worksheet function (WS) in Excel. As a worksheet function, the COUNT function can be entered as part of a formula in a cell of a worksheet.