Why don't elephants get embolisms?

[Kim]

I think, the pressure differential outside the body is slightly greater than 1 atm, and the pressure inside the lung is 1 atm.

The effect would be similar to that of diving helmets that you see tourists wear. Essentially, the cartilage inside the trunk, the skin around the pharynx, the cartilage in the trachea, and the bones in the ribs - all function like the glass dome of the diving helmet. Essentially maintaining a differential between the outside and the inside.

So the body is maintained essentially at 1 atm. Despite the outside pressure slightly higher than 1 atm.

No...I disagree. The air supplied to diving helmets for tourists is supplied at their ambient pressure....whatever that is. They aren't simply snorkeling air from the surface as elephants do.

As for slightly different.....do you think you could snorkle air through a tube if you were, say 3 meters (10ft) below the surface?

 

[fisherdvm]

Why would their pressure pop? Both the arterial system and the venous system is maintained at a pressure. I can't recall what is the pressure of the pulmonary venous and arterial system... But as long as it is slightly higher than the 1 ATM plus 4 to 5 ft of air column, no fluid would leak out.

 

[fisherdvm]

These are the readings of typical pulmonary pressure... I am prettysure 5 mm HG is much greater than that of a 5 ft column of air.

1) Right Atrial Pressure (RAP or CVP)

(2) Right Ventricular Pressure (RVP):

RVP Systolic = 20-30 mmHg

RVP Diastolic = 0 – 5 mmHg

(3) Pulmonary Artery Pressure (PAP)

PAP Systolic = 20-30 mmHg

PAP Diastolic = 8-12 mmHg

PAP Mean = 25 mmHg

(4) Pulmonary Artery Wedge Pressure (PAWP)

PAWP = 4- 12 mmHg

 

[fisherdvm]

No...I disagree. The air supplied to diving helmets for tourists is supplied at their ambient pressure....whatever that is. They aren't simply snorkeling air from the surface as elephants do.

As for slightly different.....do you think you could snorkle air through a tube if you were, say 3 meters (10ft) below the surface?

I disagree, it is not the same as ambient pressure. To keep their lung from compressing, you forgot to add the column of air that they are under.

 

[Kim]

Why would their pressure pop? Both the arterial system and the venous system is maintained at a pressure. I can't recall what is the pressure of the pulmonary venous and arterial system... But as long as it is slightly higher than the 1 ATM plus 4 to 5 ft of air column, no fluid would leak out.

Well...presumably it would be at least 1ATA plus at least 8 to 10 ft (maybe more) of water column no? Water weighs an awful lot more than air!

 

[fisherdvm]

If they dove to 33 ft, that would be 2 atm, if it is to 16 ft, that would be 1.5 atm. If the elephant dove to 3.3 ft, that would be 1.1 atm.

I venture to say, without doing mathematics, that 1.1 atm is much less than the 4 to 5 mm hg that the pulmonary artery/venous system is able to generate.

 

[fisherdvm]

As long as the 1 atm plus the 8 ft of water is lower than the elephant's systemic arterial and venous pressure, the body can adjust and maintain adequate pressure in the pulmonary arterial and venous system.

 

[Kim]

If they dove to 33 ft, that would be 2 atm, if it is to 16 ft, that would be 1.5 atm. If the elephant dove to 3.3 ft, that would be 1.1 atm.

I venture to say, without doing mathematics, that 1.1 atm is much less than the 4 to 5 mm hg that the pulmonary artery/venous system is able to generate.

Hey...come on! When have you ever seen a 3.3 tall elephant!!!

Anyway....Let's see if others chime in on this. I only posted it because I thought it was interesting. I actually already know the answer....I just watched a National Geographic program that talked about it. I thought it would be interesting to post like this though, and make people think about pressure in a slightly unusual way.

 

[Spongebobscubasteve]

First of all, why is the elephant snorkeling, is he doing for recreational purposes? If so, would he be going out with the LDS or simply by himself?
If if is for commertial purposes how would he collect data. Elephants don't have thumbs and his trunk is being used for a snorkel.

Secondly, how would he fit in the decompression chamber if the proverbial pooh did hit the fan?

 

[Kim]

Secondly, how would he fit in the decompression chamber if the proverbial pooh did hit the fan?

Good question....but he's actually free diving so presumably he won't get bent!