Subject: Breathing

Courtney Stirling Casey (stirling@gsosun1.gso.uri.edu)
Wed, 17 Jun 1998 08:24:10 -0400 (EDT)

Hi Ben,
	In some respects the way whales breathe is very similar to how
humans breathe. We both have trachea (the tube that carries air from the
outside down into our lungs). However, we inhale through our mouths and
noses and whales can inhale only through their nostrils (which are located
at the top of their head). So, when whales come to the surface they inhale
several times to charge thier bodies with oxygen. Then, the whale dives
and the oxygen from that air is moved through the body by hemoglobin
molecules (just a fancy name for the things that carry oxygen to muscle
where it is needed to do work). Whale blood has more hemoglobin that human
blood and this allows them to hold their breath for so long. Then, when
the whale surfaces again it exhales the air that has had a lot of the
oxygen removed and inhales new air. The exhalation process is caused by
muscle contration around the lungs of the whale. 
	The water or mist that you see when a whale exhales is not water
coming from its lungs, as only air does that. It is made up of water
pushed into the air when the whale begins to exhale while still under
water and moisture from the whales exhaled breath - much like when you
exhale on a cold damp day and can see your breath.
	Does this answer your question? Let me know if you need more
information.

Courtney

Courtney Stirling Casey
Department of Animal and Avian Sciences
University of Maryland, College Park

On Tue, 16 Jun 1998, tammy noteboom wrote:

> Date: Tue, 16 Jun 1998 17:53:44 -0700
> From: tammy noteboom <noteboom@means.net>
> To: stirling@gsosun1.gso.uri.edu, pita@whale.wheelock.edu
> Subject: whales
> 
> How do whales blow water out of their spouts?
> 
> Ben Noteboom
> age 7
> Hawley, Minnesota
> 
> email to: noteboom@means.net
>