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. ...harpo!inmet!apt ...hplabs!sri-unix!cca!ima!inmet!apt ...yale-comix!ima!inmet!apt