Why does vasodilation in periphery lead to reduction in blood pressure?

Hello everyone,

Ok generally what do they mean when they say vasodilation in periphery lead to reduction in blood pressure? Do I have to think of this as expanding the size of a fluid filled container so less fluid splashes againts the walls reducing pressure. Or do I have to think of this like a circuit where decreasing the resistane of a resistor results in decreased pressure just upstream of that resistor. Thank you :smile:
 
Conventional blood pressure, which has become a standard vital measurement is measured around a person's arm, where vasodilatation is relevant (large arteries, smaller arterioles and large veins.)

If the arm vessels dilate, the pressure there will decrease.

http://en.wikipedia.org/wiki/Vasodilation
 
Last edited:
Conventional blood pressure, which has become a standard vital measurement is measured around a person's arm, where vasodilatation or contraction is negligible.

If there is more room for blood in the periphery where vasodilatation occurs (the capillaries in fingers, face, organs etc), there is a little less blood in the arms (and legs and main arteries), so the measured pressure there is reduced.
Thanks a lot for the answer :smile: but here is where I'm getting confused with circuits. In a circuit if I have 2 parallel circuits, both would get the same voltage but different current depending on the resistance. So if I directly think of voltage as pressure, shouldn't the pressure be same in legs and fingers. Is this a case where the pressure and voltage analogy doesn't work. If so I understand. Thank you :smile:
 
After review, I had to make an important correction in my first post. My physiology is further than I thought.
 

Andy Resnick

Science Advisor
Education Advisor
Insights Author
7,171
1,465
Hello everyone,

Ok generally what do they mean when they say vasodilation in periphery lead to reduction in blood pressure? Do I have to think of this as expanding the size of a fluid filled container so less fluid splashes againts the walls reducing pressure. Or do I have to think of this like a circuit where decreasing the resistane of a resistor results in decreased pressure just upstream of that resistor. Thank you :smile:
There's a simplified model of blood pressure, involving the ejection volume from the heart, systemic vascular resistance, and central venous pressure:

http://en.wikipedia.org/wiki/Blood_pressure

The major driver of vascular pressure are the arterioles and capillaries. Increasing the peripheral blood flow decreases the vascular resistance, leading to a decrease in arterial pressure.
 

Want to reply to this thread?

"Why does vasodilation in periphery lead to reduction in blood pressure?" You must log in or register to reply here.

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving

Top Threads

Top