BP physiology help

[alleyb]

I have been searching for a couple of hours and I am just not putting this together. I need to understand why BP and pulse changes when you stand up. I understand orthostatic hypertension and how it relates to the sympathetic nervous system. But I need to understand the slight drop in BP that occurs and the rise in the pulse. I keep circling around peripheral resistance, gravity, I'm just not making the connection. Text web-site does not cover it. Any helpful links would be appreciated. Thanks.:banghead:

[ghillbert, MSN, NP]

It's the same mechanism as orthostatic hypotension - except that usually you have normal compensatory mechanisms such as increasing HR to compensate for reduced venous return and bring BP back to normal.

Just remember that BP = CO x TPR, and CO = HR x SV.

So anything which drops peripheral resistance or venous return will drop BP. In response, your HR will increase to compensate for reduced venous return (sensed by baroreceptors and increased via action of SNS).

Decent PPT here:

www.cord.edu/faculty/todt/306/PPT/13Chapter21-.ppt

[alleyb]

Thank you so much for your response. I already turned the lab in, but you reassured me that my answer was on track. I noticed I wrote hypertension above, I meant hypotension, I need to be careful about that.