system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:What exactly happens to your heart as you feel it drop when you are scared or upset?

if possible, the heart "breaking" feeling as well.
gpt
When under duress, your body goes into fight-or-flight mode. The sensation of your stomach/heart dropping is due to your body dumping blood to your extremities, so you can fight (or flee) more effectively.