Biologie Question #4250
D (Genre: femelle, Àge: 23 années) de Toowoomba sur 9 mai 2008 demande:
I have been told that it's useful to plot changes in systolic and diastolic blood pressure when I look at changes in mean arterial blood pressure. I'm not sure I know the reason why. Could you please advise?
vu 15765 fois
La réponse
Professor Victoria Claydon, Simon Fraser University, Burnaby, BC
répondu le 9 mai 2008
The systolic blood pressure largely represents the maximum force generated by the heart, whereas the diastolic pressure is a better indicator of the resistance (degree of constriction) of the peripheral blood vessels, especially the arterioles. The mean arterial pressure is, as its name suggests, an amalgamation of the two, but because the heart spends more time in diastole than in systole, the mean pressure is biased towards the diastolic pressure [mean pressure = diastolic pressure + 1/3 x (systolic pressure – diastolic pressure)]. Looking at all three pressures gives the most comprehensive assessment of blood pressure changes and can indicate whether the changes in blood pressure are due to changes in resistance, pumping force, or both. Furthermore, the baroreceptors (regions that detect changes in blood pressure and bring about reflex responses to control it) are differentially sensitive to systolic, diastolic and mean blood pressures.
Ajoutez à ou commentez sur cette réponse en utilisant la forme ci-dessous.
Note : Toutes les soumissions sont modérées avant d'être signalé.
Si vous avez trouvé cette réponse utile, s'il vous plait considérez faire un petit don à science.ca.