The moment you stand up, gravity tries to drain the blood from your brain. Your aortic sensors have milliseconds to violently constrict your veins and fight back.
When you lie down, your heart pumps blood easily on a flat, horizontal plane. But the second you stand up, gravity violently pulls all the blood in your upper body straight down toward your legs. Without an immediate, massive physiological correction, your brain would lose oxygen in seconds, and you would black out on the floor.
The invisible lifesaver that prevents this daily catastrophe is the Baroreflex Network. Embedded deep within the walls of your carotid arteries and aorta are microscopic, mechanical stretch sensors. In the exact millisecond you stand, these sensors detect the sudden drop in arterial pressure. They instantly fire an emergency neurological signal to your brainstem, which forces your heart to beat faster and your blood vessels to violently constrict, shooting the blood back up against gravity before you even realize it happened.
This book breaks down the incredible bioengineering of human blood pressure. We explore what happens when this delicate algorithm misfires, causing orthostatic hypotension and chronic dizziness.
Appreciate the mechanical genius of your own arteries. Learn how your nervous system fights an invisible, millisecond battle against gravity every single time you leave your bed.
Sabrina Allen
Author
baroreflex network cardiovascular physiology orthostatic hypotension autonomic nervous system blood pressure regulation human gravity adaptation bioengineering body