Does the net body volume increase at the time of erection.

[unbiased]

If a man is sitting in a water tub fully submerged( with bated breath, will an erection at this time lead to water spilling out of the tub as a result of increase in net volume of the body?

 

[sao123]

Originally posted by: unbiased
If a man is sitting in a water tub fully submerged( with bated breath, will an erection at this time lead to water spilling out of the tub as a result of increase in net volume of the body?

No. As blood fill the penis, it leaves otehr ares of the body. The volume is merely transferred from one part of the body to another.

 

[f95toli]

No, the volume probably increases. Some of the blood comes from e.g. internal organs and they do no add anything to the volume.
But of course the weight does not change (hence, the average density decreases).

 

[Stiganator]

Volume up, density down. Mass stays the same.

 

[dxkj]

breathe at all and it will

 

[Mark R]

Probably not. The blood will come from veins and internal organs. As the blood is diverted, the veins and organs collapse down (reduce in volume). When blood is moved from one organ to another, it doesn't leave an empty air-filled gap. The organ or blood vessel collapses to occupy a smaller volume.

Similarly, as most of the vital organs are in the chest and abdomen (ignoring breathing) the chest and abdomen will reduce in volume (because the collapse of the organs and veins won't generate a vacuum).

 

[Peter]

That's been a reader's question in Playboy ages ago (when I still had to "borrow" Dad's). The answer was "no, even if you do manage to get it up while not breathing - because the blood will retract from elsewhere in the body".

See, I do read the interesting articles 😉

And how's this highly technical?

 

[PowerEngineer]

Originally posted by: Peter
That's been a reader's question in Playboy ages ago (when I still had to "borrow" Dad's). The answer was "no, even if you do manage to get it up while not breathing - because the blood will retract from elsewhere in the body".

See, I do read the interesting articles 😉

And how's this highly technical?

Well, it can't be highly technical if you're quoting Playboy as a authoritative source! 🙂

Do you really think that we lose a pint of volume whenever we donate blood?

 

[Peter]

Yes we do. Do /you/ think you're forming an empty cavity when you're donating blood?

 

[Xdreamer]

who said playboy wasnt highly technical ... LOL
no it would not be an increase in volume. Blood, a liquid, has a fairly set volume. However, if this person continues to refrain from breathing, a series of biological reactions will occur resulting in gas bloating which would increase body volume. (This would of course be after he died, and the bloating would have nothing to do with an erection.)

 

[Sunner]

Originally posted by: dxkj
breathe at all and it will

Probably not a good idea if you're fully submerged.

 

[BrownTown]

The resulting volume would be aproximately the same. There would likey be very small differences based on tthe pressure of blood in the penis vs the pressure it was origionally at. For example blood in the veins is at a lower pressure than the arteries, so the higher pressure penile blood would likely result in a small reduction in volume.

As for losing a pint of size when you donate blood. You bet your ass you do. However the body pretty rapidly makes up for it by absorbing water from your intestince while at the same time reducing the amount of water lost by urine. Also, whenever I give blood I usually drink a sprite or gatorade right after to replenish the lost water and sugars as soon as possible. Red blood cells kept in the bone marrow are also rapidly released to make up for those lost, so you should return to normal in maybe a few hours (no expert here, so doctor would know more for sure).

 

[Witling]

No practical difference. Did we not learn in physics that liquids are, for a practical matter, incompressible? The blood forming the blood component of an erection is simply a liquid, similar the the liquids everywhere else in your body. It occupies the same volume at any practical measurement level. Now, if you were to talk about air-filled spaces in the body a two inch change in depth would result in a .0050 change in volume. Now your talking!!!