I got this project for school, and one of the largest questions are: Why can you faint if you stand still for too long? I don't really know how to formulate myself in that sense... so if you we're able to explain - it would be a massive help
I can't find anywhere on the web how to explain "why you faint if you stand still for too long" .
I can't find anywhere on the web how to explain "why you faint if you stand still for too long" .
1 Answer
Here's what I find.
Explanation:
What is fainting?
Fainting is a brief, sudden loss of consciousness.
You become unresponsive and may fall.
The medical term for fainting is syncope (from Greek syn "together" + kope
"a cutting short") [of blood flow to the brain].
How does standing for a long time cause fainting?
It is harder for the heart to pump blood up to the brain than down to the toes.
When you stand for a long time, especially in the heat, blood from your upper body can pool in your legs.
The blood supply to the brain decreases, and you faint.
What is happening in the body?
Your body has a feedback system of sensors in the arteries leading to the brain.
These sensors control many nerve and hormone signals that change your heart rate, constrict your blood vessels, and maintain your blood pressure.
When the blood pools in your legs, the feedback system triggers your heart rate and blood pressure to drop suddenly.
The blood flow to your brain decreases.
How is the brain involved?
The brain needs a constant supply of sugar and oxygen.
If blood flow drops, the brain goes into an energy-conserving shutdown.
It sends signals to your nerves and muscles to stop.
You lose consciousness and slump to the ground.
