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

251 views

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

36 Answers

Anonymous 0 Comments

Your circulatory system is pressurized; everything you hear about blood pressure is literally referring to the pressure of blood in your blood vessels. So an open wound won’t suck in seawater.

However, the blood pressure away from major veins and arteries isn’t that high, so the blood isn’t spraying out (think about how slowly blood comes out of a paper cut). That means that contaminants in the water like parasites or bacteria can get into your body if the water mixes with your blood or if they can “swim” into your body faster than blood flows out.

Anonymous 0 Comments

To piggyback off this, can a wound (like a cut) heal if you’re indefinitely underwater?

Anonymous 0 Comments

Your circulatory system is pressurized; everything you hear about blood pressure is literally referring to the pressure of blood in your blood vessels. So an open wound won’t suck in seawater.

However, the blood pressure away from major veins and arteries isn’t that high, so the blood isn’t spraying out (think about how slowly blood comes out of a paper cut). That means that contaminants in the water like parasites or bacteria can get into your body if the water mixes with your blood or if they can “swim” into your body faster than blood flows out.

Anonymous 0 Comments

Your circulatory system is pressurized; everything you hear about blood pressure is literally referring to the pressure of blood in your blood vessels. So an open wound won’t suck in seawater.

However, the blood pressure away from major veins and arteries isn’t that high, so the blood isn’t spraying out (think about how slowly blood comes out of a paper cut). That means that contaminants in the water like parasites or bacteria can get into your body if the water mixes with your blood or if they can “swim” into your body faster than blood flows out.

Anonymous 0 Comments

the circulatory system is pressurized in a sense. this is whole deal with ” blood pressure”

so to some extent the internal* pressure of the system would keep the water out up to ap oint where external pressure exceeds internal* one, or if blood loss is severe enough that blood pressure drops.

Anonymous 0 Comments

To piggyback off this, can a wound (like a cut) heal if you’re indefinitely underwater?

Anonymous 0 Comments

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.

Anonymous 0 Comments

To piggyback off this, can a wound (like a cut) heal if you’re indefinitely underwater?

Anonymous 0 Comments

the circulatory system is pressurized in a sense. this is whole deal with ” blood pressure”

so to some extent the internal* pressure of the system would keep the water out up to ap oint where external pressure exceeds internal* one, or if blood loss is severe enough that blood pressure drops.

Anonymous 0 Comments

the circulatory system is pressurized in a sense. this is whole deal with ” blood pressure”

so to some extent the internal* pressure of the system would keep the water out up to ap oint where external pressure exceeds internal* one, or if blood loss is severe enough that blood pressure drops.