A properly functioning society requires good citizenship. We need barbers and bankers, dishwashers and doctors…each playing a role to help things run smoothly for all. Veins, specifically those in the lower extremity are unsung heroes…much like waste disposal workers. How many hot summer days would it take to convince you that garbage collection is one of the most crucial services to humanity?!
The role of veins in general is to return flow back to the heart so that oxygen/nutrient rich blood can circulate and nourish our cells. The veins above the heart have it pretty easy. Gravity is their friend, helping to move blood down towards the chest. Lower extremity veins, especially when we sit or stand, have to move flow upwards against gravity. This problem would easily be solved if G-d put hearts in our feet…pumping vigorously and forcing flow upward. While we don’t have hearts down there, our bodies make do with the next best thing: the Calf Muscle Pump.
Indulge me for a moment, if you will: Move your ankles up and down. When you do so, you’ll feel your calf muscles rhythmically contracting and relaxing. When your calf muscles contract, they squeeze and squish nearby structures, including the veins in your legs. When they squeeze the veins, the force generated propels flow upwards towards the chest. Fabulous, except for one small hiccup: gravity drags the flow right back down towards the feet.
Fortunately, most of us are blessed with veins that have a series of valves that are designed to allow for one-way flow. When the Calf Muscle Pump sends flow up, the valves are forced open. When gravity drags flow downward, the valve leaflets are forced to shut against each other and block that downward flow…UNLESS THE VALVES ARE BROKEN.
This leads us to the next chapter: Venous Pathophysiology…or how things go wrong.