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I was reading you Q&As on air pressure and you had a question on syringes. When a Conservation Officer shoots an animal with a syringe how does the sedative go into the animal without any pressure exerted on the end of the needle? Are there any expearments to show how it works?
BlueJay Elementary, Abbotsford, BC Canada
I scouted on the web a little bit and found
, of a
manufacturer of syringe darts, the kind used by Conservation Officers
to tranquilize or vaccinate animals. Look under "General Information"
to get schematic diagrams and instructions for use. Don't try any of
this at home unless you are a Conservation Officer.
The long and the short of it is that the syringe is
pressurized with air behind the plunger in back of the drug-containing
part of the syringe. The needle of the dart is closed on its pointed
tip and there are holes on the side of the needle for the drug to flow
out (this is so the hole is not closed off if the tip bends on impact).
A silicone sleeve is placed around the part of the needle with the
holes before the drug is put in the syringe and before the air behind
the plunger is pressurized. That way the drug won't come out while the
sleeve is in place. When the needle penetrates the animal's skin, the
sleeve slides back, and the air pressure pushes the drug out.
(republished on 07/18/06)
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