BR faulty data In passage? Pascals of blood vs atmospheric?

[hellocubed]

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In one of BRs passages they state that artery Blood has gauge pressure of 10000 Pa.
This is not mentioned in the passage, but it should be known that atmospheric pressure is over 100,000 Pa.


Then Br asks if blood has a greater pressure than atmospheric and the answer is yes....
........
What?

We just saw that blood has lower pascals than atmospheric... So......
Bad question?

 

[chiddler]

If blood has a greater gauge pressure or absolute pressure?

 

[MedPR]

Gauge pressure = Absolute - Atmospheric

 

[hellocubed]

Oh how are the different?
I thought pressure was pressure

 

[chiddler]

Gauge pressure = Absolute - Atmospheric

Oh how are the different?
I thought pressure was pressure

mind reader!

 

[MedPR]

If the gauge pressure is positive, then the thing has higher pressure than atm. If negative, then less.

The best example I can think of is inhaling/exhaling. When inhaling, we consider the pleural cavity pressure to be negative. However, you know there is no such thing as less-than-zero pressure. The "negative" pleural pressure is negative gauge pressure, which means it is lower than atmospheric but still greater than zero.

This is a good outline of it: http://www.engineeringtoolbox.com/pressure-d_587.html