epinephrine?

[majik1213]

if anyone has FA2010 and wouldn't mind helping me out here I'd appreciate it. Page 236 .. the upper middle graph at the bottom of the page (it's one of those six graphs located in top middle - it shows epinephrine's effects on blood pressure).

now look on page 237 - the top left graph (which again shows blood pressure + EPI under normal conditions). Why are these two graphs different? Which one is right? I am tempted to go with the one on page 237 ..


EDIT: nevermind I figured it out!

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[kunfu]

if anyone has FA2010 and wouldn't mind helping me out here I'd appreciate it. Page 236 .. the upper middle graph at the bottom of the page (it's one of those six graphs located in top middle - it shows epinephrine's effects on blood pressure).

now look on page 237 - the top left graph (which again shows blood pressure + EPI under normal conditions). Why are these two graphs different? Which one is right? I am tempted to go with the one on page 237 ..


EDIT: nevermind I figured it out!

Well now Im confused to, would you mine explaining what you figured out. Im sure im missing something obvious but its confusing me.

 

[mrmandrake]

Someone correct me if I'm wrong.

A large dose of EPI acts in a similar way to a dose of NE, namely, there is no B2 effect, so the diastolic BP doesn't fall like it does in the graph on page 236. I'm guessing they used a medium dose for the example on page 236 since the systolic goes up and the diastolic goes down. I believe a low dose of EPI would make both go down (the systolic going ever so slightly down).

 

[kunfu]

Someone correct me if I'm wrong.

A large dose of EPI acts in a similar way to a dose of NE, namely, there is no B2 effect, so the diastolic BP doesn't fall like it does in the graph on page 236. I'm guessing they used a medium dose for the example on page 236 since the systolic goes up and the diastolic goes down. I believe a low dose of EPI would make both go down (the systolic going ever so slightly down).

Yeah but on pg 237 it says that its a large dose, meaning that both B1 and B2 should be activated like on the graph on pg 236, right?

 

[mrmandrake]

Yeah but on pg 237 it says that its a large dose, meaning that both B1 and B2 should be activated like on the graph on pg 236, right?

A large does of EPI means there is no B2 effect. So on page 237, they use a large dose and you see that the diastolic doesn't drop, it goes up. On page 236, they don't use a large dose, and you see the B2 effect kick in and the diastolic drops.

 

[username456789]

Yeah but on pg 237 it says that its a large dose, meaning that both B1 and B2 should be activated like on the graph on pg 236, right?

A high dose of Epi has primarily alpha agonist effects, and thus net vasoconstriction.

Edit: What mrmandrake said

 

[kunfu]

A high dose of Epi has primarily alpha agonist effects, and thus net vasoconstriction.

Edit: What mrmandrake said

Ahhhh....the important fact I had forgotten that was making this very confusing. Thank you, that clears it up.

 

[hartbot]

Follow up Q:

As the diagram shows, B2 and a1 are the determinants of diastolic pressure whereas B1 determines systolic pressure?

I don't think I've ever learned which factors are responsible for the diff aspects of BP. I know stroke volume is the most impt determinant of PP, but thats it.

 

[username456789]

Follow up Q:

As the diagram shows, B2 and a1 are the determinants of diastolic pressure whereas B1 determines systolic pressure?

I don't think I've ever learned which factors are responsible for the diff aspects of BP. I know stroke volume is the most impt determinant of PP, but thats it.

Off the top of my head, that makes perfect sense (a1 and b2 govern blood vessel resistance, b1 is associated with inotropy/pumping blood during systole...that's my dumbed down reasoning at least).

 

[Rabbit Hole]

Follow up Q:

As the diagram shows, B2 and a1 are the determinants of diastolic pressure whereas B1 determines systolic pressure?

I don't think I've ever learned which factors are responsible for the diff aspects of BP. I know stroke volume is the most impt determinant of PP, but thats it.

a1 - vasoconstriction (skin, viscera)
b2 - vasodilation (skeletal)

b1 - heart - increases HR and contraction

That's my quick and dirty.