Real Seals Wear Helmets
The northern elephant seal can dive deeper
and longer than a sperm whale, stay submerged for up to two hours, and reach
depths of more than a mile. Doctors may be able to use the new knowledge
of the seal's unusual physiology to develop treatments for heart attacks
and strokes in humans
Story by Robert Evans
Illustrated by Alejandro Cruz
Researchers in California, Massachusetts
and British Columbia are trying to understand how an elephant seal can dive
so long and so deep. They fit the animal with a strong plastic helmet sealed
around the neck, and then flood it with water. When that happens, the animal
holds its breath, a natur
al
reaction to having water on its face, and just as it does in a real dive.
The scientists then put the elephant seal into an MRI (Magnetic Resonance
Imaging) machine, which can make images of the internal structures of the
animal's body. Such machines are used for many diagnoses in hospitals. Pictures
of the blood vessels while the animal is "diving"
show that blood travels only to organs that need oxygen: brain, heart, muscles.
Blood-flow, and therefore oxygen-supply, shuts down to the kidneys and to
the body's extremities. The animal's metabolism slows down so that it doesn't
need as much oxygen, and what it needs is stored in its spleen and muscles.
The seal is one of the world's greatest submarines, and may give us clues
to help humans in medical crises.
Please see the full story for more on this amazing pinniped.