How can the heart be strong enough to pump blood up your legs against gravity?
The heart works only against the viscous resistance of the system, not against gravity, even in vascular loops above the heart in which the siphon principle operates. Veins must work against gravity to return blood the heart. The muscles of the leg help that process, and valves within the veins usually keep the moving blood …
How can the heart be strong enough to pump blood up your legs against gravity? Read More »