ELI5, if you get an injury underwater (say in the ocean) that opens the skin and bleeds, what stops your body from intaking water?

Question

ELI5, if you get an injury underwater (say in the ocean) that opens the skin and bleeds, what stops your body from intaking water?

In: 1476

Answer 1

It does happen in fresh water and is called tissue maceration. The water isn’t going to enter the circulatory system due to clotting and vasoconstriction though (and hydrostatic pressure for arterioles), and only seeps into injured tissue and skin. It just happens slowly. In ocean water, there is too much salt for water to enter the body. Instead water travels the other way.