Video transcription

We want to talk about what blood pressure is. Blood pressure is divided into systolic pressure, and diastolic pressure, and those pressures represent different aspects of the cardiac cycle. When you get your recording, you may get 120/80. That top number is your systolic pressure, and the bottom number is your diastolic pressure, and what those pressures represent is a pressure within the arterial system. This is the beginning of the arterial system, which is the aorta, and this is a representation of the pressure in the aorta when you take someone's blood pressure. So the systolic pressure is the pressure within the aorta just after that heart contracts. This aorta is filled up with higher amounts of pressure. So it's the pressure within the aorta or the arterial system; more so the brachial artery; after that heart contracts. The diastolic pressure is the pressure within that arterial system just after the heart relaxes, so we have constant contraction; right here in this ventricle; shoots blood up through the aorta, and then it relaxes. The pressure decreases, so that's why the diastolic is a little bit lower. Now we're going to take an actual patient example, and see how these pressures relate to someone's actual reading.