Well, some of the “C” section of the Encyclopedia of Marine Mammals is serious science, so much so that it can be extremely mind numbing to read. This holds true for the article titled Circulatory System. So instead of getting into the nitty gritty details of the anterior vena cava or the hepatic sinus, I’m going to skip right to one word that popped out at me: windkessel.

It seemed so out of place among all the heart and blood vessel terms. Windkessel sounds like a special type of alternative energy device or some type of fancy weather predicting doodad. But here’s a clue, this is where I first spotted it used in a sentence. “It has been proposed that the aortic bulb acts as a windkessel.” (This is referencing the aortic bulb in pinnipeds, especially phocid seals aka true seals aka earless seals.) Now when I flipped to the glossary, here’s what it said under windkessel: “A capacitance blood vessel, which due to elastic properties in its wall, first expands and accepts blood volume on blood entry and then passes blood onward due to recoil within its wall.”

This sounds like a type of vessel pump. Online medical dictionaries state it’s a chamber to convert pulsating blood into smoother flowing blood more fitted for traveling through the rest of the body. Well, there you have it…a windkessel.