@Sarim,drona99,Raheem ..... - maryam2009

[ArchivalUser]

NBME5 block 3 q10

please answer the q with explanation.Thank you

[ArchivalUser]

Stem Q is asked about the effect of a drug that dec.BP ,then after administration of the first drug add another drug to make inc.in BP and dec. in HR?

prazosin is selective for the alpha-1 receptors on vascular smooth muscle. These receptors are responsible for the vasoconstrictive action of norepinephrine, which would normally raise blood pressure. By blocking these receptors, prazosin reduces blood pressure.

When norepinephrine acts as a drug it increases blood pressure by increasing vascular tone through α-adrenergic receptor activation. The resulting increase in vascular resistance triggers a compensatory reflex that overcomes its direct stimulatory effects on the heart, called the baroreceptor reflex, which results in a drop in heart rate called reflex bradycardia.

if there is any oponian please add it,Thank you in advance.

[ArchivalUser]

i agree maryam.

U can also draw graph like this one say like if we Pretreated the pt. with Hexamethonium(Ganglionic Blocker) and upon giving NE........how the graph will look like in that case.

-there will be NO Change in Mean B.P. (as alpha-1 effect is not interrupted), so it will stay High.
-Reflexive effect on heart is blocked ----allowing "Direct beta-1 effect" to take in effect---->inc HR

[ArchivalUser]

Thank you Sarim