why is afterload increased in hypovolemic shock

[mjmdjd1]

Why is afterload increased in hypovolemic shock? I get that you have volume/fluid loss in hypovolemic shock. Therefore you would have less blood to pump through the aorta and also a decrease in stress. So shouldn't that be a decrease in afterload?

I know that preload will be decreased with hypovolemic shock due to the same paradigm mentioned above but what about afterload?

@kirbymiester @Phloston

Edit: The same thing can be said about cardiogenic shock. We have left ventricular dysfunction with cardiogenic shock hence why we get low cardiac output. Why then do we get an increased afterload in cardiogenic shock?

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[MrGrrrMonster]

Sympathetic response leading to vAsoconstriction and increased SVR.

 

[django7]

MrGrrrMonster is right. Hypovolemia (fluid losses or gross hemorrhage) leads to activation of renin angiotension aldosterone system and sympathetic autonomic nervous system-> constriction of arterioles resulting in cold extremities. Decreasing flow to limbs and gut and redirecting flow to vital organs (brain and heart).

in contrast to septic shock. where there is massive inflammation and vasodilation. initially warm extremities due to decreased SVR but will eventually progress to vasoconstriction and cold extremities for the same reasons as above