@maryam2009, @shigatoxin, @anyone.... - zen786

[ArchivalUser]

theres very few things i dont understand.....

ONE HAPPENS TO BE MEAN ARTERIAL PRESSURE!!!!

MAP = CO x TPR is the only thing i get.... so anyone wanna help please....

[ArchivalUser]

watch this http://www.youtube.com/watch?v=IIYK4S1Rb...re=related

[ArchivalUser]

well MAP is basically aortic pressure cuz most artierl pressure in systemic circuit is due to the aorta....IE normal MAP is 93mmHg

n u kno how to calculate MAP=1/3Sys+2/3diastole

so normal aortic pressure should be 120/80

so 1/3 of aortic sys is 40mmHG and 2/3 diastole is 53mmhg which equals the MAP

n it is this MAP which was generated by the Aorta to facilliate return of blood to the RAtrium(which has 0-8 systolic pressure) thats why in RHF RA pressure increase n blood as trubile returining to RA n u get dependent ankle edema

[ArchivalUser]

but the main thing that control MAP is the extension of small arteries(arterioles) which is to say TPR.....

n factors that determine CO is CO=HR x SV


also impt point is TPR is a index of diastolic pressure where as SV is a index of systolic BP....n HR is controlled by the SA node


this also explains why is ARegure we have a very wide Pulse pressure---cuz the incompentent aortic valve cannot maintain diatolic volume(pressure) from the regurge so diastolic pressure decreases.....

and aortic systollic pressure Inreaces cuz the regurged blood increases preload which streaches the LV(which has normal myocardium) and via FRANK-starling CONTRACTITILY INCREASES GREATLY to keep COutput normal


GL

[ArchivalUser]

thank you so much !!!