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The term bacteria was devised in the 19th century by German biologist Ferdinand Cohn. He based it on the Greek word "bakterion" meaning a small rod or staff. Cohn is considered to be the father of modern bacteriology.
When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.
The familiar sounds of your heart are made by the heart's valves as they open and close.
The heart is located in the center of the chest, with part of it tipped slightly so that it taps against the left side of the chest.
In 1844, Charles Goodyear obtained the first patent for a rubber condom.