[net.sci] Do ants have hearts?

jefff@cadovax.UUCP (Jeffery H. Fields) (06/11/85)

Here is a question for the entomologists and the invertebrate zoologists:

     How is food and oxygen circulated in invertebrates?

This question came up at lunch the other day.  It started with, "Do ants have
hearts?" and progressed onto, "How do worms breathe?"  Any shared knowledge on
this topic would be greatly appreciated.

-- 

				Jeff Fields
				{ucbvax,ihnp4,decvax}!trwrb!cadovax!jefff

lonetto@phri.UUCP (Michael Lonetto) (06/18/85)

> 
> Here is a question for the entomologists and the invertebrate zoologists:
> 
>      How is food and oxygen circulated in invertebrates?
                                            ^^^^^^^^^^^^^

The question is a little broad as phrased.  Since the subjuct line mentioned
ants:

Insects have an "open" circulation system consisting of "hemolymph",
(which serves the purposes of blood) which is circulated by a simple
heart and dorsal artery.  The artery leads to the ends of the organism
where the "blood" flows into the body cavity and, eventually, back to
the heart(which has a direct input).  Oxygen exchange is accomplished by
a system of trachea which branch throughout the body and are connected
to the outside air by spiracles, which are small openings in the
exoskeleton.  Since oxygen and CO2 don't have to diffuse far from the
trachea a fairly simple circulatory system is quite efficient.  

Incidentally, this is one of the factors limiting the size of insects.
Aren't you glad?

Michael Lonetto   PHRI

allegra!phri!lonetto
-- 
Michael Lonetto  PHRI  NYC  (allegra!phri!lonetto)

"Some win, Some lose, Some refuse to play"

apt@inmet.UUCP (06/18/85)

  As far as I can remember from 9th grade biology, invertebrates have an
"open-ended" circulatory system.  That is, they have a heart (or hearts)
with a tube on opposite ends, one leading to the front and one leading
to the back.  The blood is dumped into the body at one end, flows through 
the tissues to the other end, where it is sucked up again and recirculated.
I'm pretty sure this is true for insects and worms.  Also, worms have five
hearts connected together, like a string of beads.


				Alan Taylor
                                Intermetrics, Inc.
                                Cambridge, Mass.

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