Can anyone explain, in simple lay-person's words, the mechanics of what is happening when a manual blood pressure is being taken. The cuff squeezes the arm to the point where the provider hears no pulse. Then they hear a pulse. Then there is so little pressure they stop hearing a pulse. How does this make the top # being the systolic and the bottom being diastolic ? I do it with no problem, I just want to understand the science behind it. Thank you in advance.