Vasoconstriction in response to drop in blood pressure

[arossm]

I have trouble understanding the compensatory mechanism of vasoconstriction in response to low blood pressure.

Blood pressure is defined as the pressure of blood on the walls of blood vessels.

What does "the pressure of blood on the walls of blood vessels" have to do with anything?

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[Neuroplasticity]

With low pressure of blood on the walls of blood vessels, fluid/nutrients may not be forced out of vessels so organs may not get the nutrients they require.

Is this what you were asking? If not, what are you confused about?

 

[arossm]

With low pressure of blood on the walls of blood vessels, fluid/nutrients may not be forced out of vessels so organs may not get the nutrients they require.

Is this what you were asking? If not, what are you confused about?

You're thinking more on the capillary level. Ok, let me elaborate my confusion. I read textbooks and they explain that if blood pressure drops, the body will try to get that pressure back up.

Blood pressure by itself doesn't mean anything. Higher blood pressure means more ______. What is that "______." What is it doing for the body. To stay alive? Yes, but how?

These books are too lazy to state explicitly what anything means. They walk you half way but never the whole way.

Now, aside from that, vasoconstriction actually increases afterload. If anything, less resistance against the pumping heart is what should be beneficial, not resistance to blood pumping.

 

[Neuroplasticity]

Blood is used as a transport system between the external environment and organs. Exchange is only performed at the capillary level, the larger vessels are used for transport. Blood pressure helps you stay alive by forcing fluid/nutrients out of vessels so organs can get nutrients.

The body compensates to increase BP when it is low is so that your organs are getting nutrients, your heart having to work harder is a less important side effect.

 

[Palibabiix13]

Vasoconstriction is the process of smooth muscle constricting the walls of your blood vessels. When that happens the cross-sectional area of the blood vessel decreases, i.e. the pressure increases. P=F/A. By decreasing the area we are increasing the pressure. The pressure of blood on the walls has a lot to do with its movement.
Blood travels from an area of high pressure to an area of low pressure. By compressing the walls of veins, for example, we allow the blood to travel upwards back to the heart. This is why low blood pressure is bad. If we consistently had low blood pressure we would be preventing oxygen and other nutrients from reaching tissues. This is why people with low blood pressure get disease.

 

[arossm]

So you're saying it speeds up the circulation, correct? How would I know that, aside from imagination? Is there a mathematical formula?

 

[longhaul3]

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[Kyle12345]

Nvm