There were other applications proposed in the early days of the. Internet, including packet based voice communication (the. precursor of Internet telephony), various models of file and disk. sharing, and early âwormâ programs that showed the concept of. agents (and, of course, viruses). A key concept of the Internet is.
View All. For a long time, normal blood pressure was defined as 120/80 mm Hg (systolic/diastolic). Recently, however, the American Heart Association revised its guidelines about what an optimal blood pressure range is, and when blood pressure is considered too high or too low. While 120/80 used to be considered normal, the new guidelines define three levels of abnormal blood pressure values. 120-139 / 80-89 is now considered to be âprehypertensionâ (or âalmost high blood pressure), and doctors are watching blood pressures in this range more carefully than in the past.
A normal blood pressure for a healthy adult ranges from 90 to 120 mm Hg systolic and from 60 to 80 mm Hg diastolic. Under normal circumstances, blood volume remains constant at 5,000 mL. blood pressure with a systolic of 140 mm Hg or higher or a diastolic pressure of 90 mm Hg or higher is considered high, although for patients with certain chronic conditions, like coronary artery disease, the guidelines vary.