 This video will cover the following objective from cardiovascular physiology part two blood vessels to find blood pressure Explains systolic, diastolic and pulse pressures the blood pressure is the force of blood pushing against the vessel wall as the ventricles eject blood into the arteries this increasing volume of blood increases the pressure and Then blood will flow from areas of high pressure in the arteries Towards areas of lower pressure So blood will flow from the arteries towards the capillaries then into the venules and veins Eventually returning to the atria of the heart or the value of the blood pressure is the lowest So every time the heart ejects blood There's an increase in the arterial blood pressure from The lowest value of blood pressure in an artery to the highest value So the lowest value we call diastolic pressure and the highest value we call systolic pressure And the difference between systolic and diastolic is what's known as the pulse pressure that is The pulse that you can feel if you place your finger on an artery and feel the expansion of an artery with each heartbeat When the blood pressure is measured, it's usually measured in a muscular arteries such as the brachial artery in the arm And so we can measure the values of the systolic and diastolic pressure and then calculate the corresponding pulse pressure We can also calculate the mean arterial pressure Which is a time-weighted average of blood pressure. It's not just systolic plus diastolic divided by two Instead, we'll calculate this mean arterial pressure as one-third systolic pressure plus two-thirds diastolic pressure reflecting the longer amount of time that the heart spends in diastole compared to systole blood pressure is commonly measured using a Blood pressure cuff, which is also known as a sphmomonometer and a stethoscope the blood pressure cuff or sphmomonometer is Wrapped around the arm and as it's pumped up it creates a pressure pushing down on the artery When that pressure is greater than the systolic pressure The cuff will prevent blood from flowing through the artery When the pressure of the cuff is between the systolic and diastolic pressure This will create a turbulent blood flow and The turbulent blood flow creates a sound that can be heard when listening to an artery with a stethoscope if you listen to an artery in the forearm with the stethoscope while the Cuff pressure on the arm is between systolic and diastolic pressure you can hear a sound with each pulse known as the sound of karate cough resulting from turbulent blood flow through that artery Once the cuff pressure is lower than the diastolic pressure Bloods able to flow smoothly through the artery and doesn't create any more sounds of karate cough therefore when we measure the blood pressure as We're releasing the cuff pressure the appearance of the sound of karate cough the first sound heard indicates the systolic pressure and The disappearance of the sound of karate cough the very last sound heard indicates the diastolic pressure After measuring the systolic and diastolic pressure we can calculate pulse pressure as the difference For example if systolic is 115 and diastolic is 75 we can calculate Pulse pressure equals 40 millimeters mercury And this pulse pressure is significant in that it is proportional to the amount of blood Pumped out of the heart with each heartbeat that is pulse pressure is proportional to the stroke volume We can calculate mean arterial pressure Which is the time-weighted average of the blood pressure within the large artery as One-third systolic pressure plus two-thirds diastolic pressure Or we could take diastolic pressure and add one-third pulse pressure either way it will calculate the same value notice that it's not Systolic pressure plus diastolic pressure divided by two It's not the simple averaging of systolic and diastolic pressure rather. It's a time-weighted average Which reflects the fact that the heart spends more time in diastole compared to systole