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Structure and function in the nematode pharynx

III. The pharyngeal pump of Ascaris lumbricoides

Published online by Cambridge University Press:  06 April 2009

C. J. Mapes
C. J. Mapes
Affiliation:
Department of Zoology, University of Bristol*
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Extract

The pharyngeal pump of Ascaris has been shown to have a very high capacity. While the contraction rate of the organ is probably of the same order as those of complex pharynges, the volume of material ingested at each pump is relatively higher. It is suggested that the pharynx acts as a simple two-stage pump in which half the lumen is filled with food at any one time.

It has been suggested that the antagonism to the radial musculature of the pharynx resides in changes related to an increase in the diameter of the pharynx during the opening of its lumen. It is suggested that the closing of the lumen is facilitated by the increased tension in the outer coat of the pharynx and in the suspensory strands of the marginal tissues; and by the contraction of the radial musculature that is orientated towards the sides of the sectors of the pharynx, towards the marginal tissues.

I would like to thank Professor J. E. Harris and Dr H. D. Crofton for their help and criticism during the course of this work, which was carried out during the tenure of a Postgraduate Studentship awarded by the Agricultural Research Council.

Type
Research Article
Information
Parasitology , Volume 56 , Issue 1 , February 1966 , pp. 137 - 149
Copyright
Copyright © Cambridge University Press 1966

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References

REFERENCES

Bennet-Clark, H. (1963). Negative pressures produced in the pharyngeal pump of the blood sucking bug, Rhodnius prolixus. J. exp. Biol. 40, 223–64.CrossRefGoogle Scholar
Doncaster, C. C. (1962). Nematode feeding mechanisms. 1. Observations on Rhabditis and Pelodera. Nematologica, 8, 313–20.CrossRefGoogle Scholar
Hanson, J. & Lowy, S. (1960). Structure and function of the contractile apparatus in the muscles of invertebrate animals. Structure and Function of Muscle (ed. Bourne, G. H.). London.Google Scholar
Harris, J. E. & Crofton, H. D. (1957). Structure and function in the nematodes: internal pressure and cuticular structure in Ascaris. J. exp. Biol. 34, 116–30.CrossRefGoogle Scholar
Hill, A. V. (1938). The heat of shortening and dynamic constants of muscle. Proc. R. Soc. B, 126, 136–95.Google Scholar
Hobson, A. D. (1948). The physiology and cultivation in artificial media of nematodes parasitic in the alimentary tract of animals. Parasitology, 38, 183–227.CrossRefGoogle ScholarPubMed
Linford, M. B., Oliviera, I. M. & Ishii, M. (1949). Paratylenchus minutus, a nematode parasitic in roots. Pacif. Sci. 3, 111–19.Google Scholar
Mapes, C. J. (1965 a). Structure and function in the nematode pharynx. I. The structure of the pharynges of Ascaris lumbricoides, Oxyuris equi, Aplectana brevicaudata and Panagrellus silusiae. Parasitology, 55, 269–84.CrossRefGoogle ScholarPubMed
Mapes, C. J. (1965 b). Structure and function in the nematode pharynx. II. Feeding in Panagrellus, Aplectana and Rhabditis. Parasitology, 55, 583–94.CrossRefGoogle Scholar
Martini, E. (1916). Die Anatomie der Oxyuris curvula. Z. wiss. Zool. 116, 137–534.Google Scholar
Roche, M., Martinez-Torres, C. & Macpherson, L. (1962). Electroesophagogram of individual hookworm (Ancylostoma caninum). Science, 136, 148–50.CrossRefGoogle ScholarPubMed
Rhoades, H. L. & Linford, M. B. (1961). A study of the parasitic habit of Paratylenchus projectus and P. dianthus. Proc. helminth. Soc. Wash. 28, 185–90.Google Scholar
Schneider, A. (1866). Monographic der Nematoden. Berlin.Google Scholar
Weis Fogh, T. (1956). Biology and physics of locust flight. J. exp. Biol. 33, 668–84.Google Scholar
Wells, H. S. (1931). Observations on the blood sucking activities of the hookworm Ancylostoma caninum. J. Parasit. 17, 167–82.CrossRefGoogle Scholar