Blood pressure: understanding mean arterial pressure

unit 3 week 11 lesson 5

what is bp

force exerted by blood on the walls of blood vessels. It is one important measure of cardiovascular health. its expressed as two values systolic and diastolic 

systolic pressure 

higher value and represents the pressure in arteries when the heart contracts (systole)

diastolic pressure

lower value and represents the pressure when the heart is at rest (diastole) between beats

how do we measure blood pressure

in millimetres of mercury (mmHg) and a healthy bp is 120 mmHg (systolic)/80mmHg diastolic

mean arterial pressure (MAP)

• this is the average (mean) bp in a persons arteries during one cardiac cycle

• you will see that the heart spends more time in diastole

• Therefore, arteries experience the lower (diastolic) pressure for more time than they do the higher (systolic) pressure

• To calculate a person's mean arterial pressure, the equation is:

MAP = diastolic pressure + 1/3 (systolic pressure-diastolic pressure)

what are the two ways ur body can adjust ur mean arterial pressure thru the cardiovascular system 

It can adjust it by changing the heart's activity, which must create pressure to move blood through your vessels, as you saw in the cardiac cycle. It can also be adjusted by altering the radius of blood vessels

cardiac output (co) equation

map/total peripheral resistance (TRP)

total peripheral resistance and vasoconstriction/dilation

vasoconstriction = higher total peripheral resistance bc it increase resistance

vasodilation is opposite

map equation

map= co x tor