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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.
Normal urine is sterile. It contains fluids, salts, and waste products. It is free of bacteria, viruses, and fungi.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
The most dangerous mercury compound, dimethyl mercury, is so toxic that even a few microliters spilled on the skin can cause death. Mercury has been shown to accumulate in higher amounts in the following types of fish than other types: swordfish, shark, mackerel, tilefish, crab, and tuna.
Today, nearly 8 out of 10 pregnant women living with HIV (about 1.1 million), receive antiretrovirals.