Excretory Systems, Nitrogen Excretion, Water and Ionic Regulation

  • Leslie H. Chappell
Part of the Tertiary Level Biology book series (TLB)


The excretory system of all animals is responsible for maintaining a relatively constant internal environment in the face of an ever-changing external environment. It follows, therefore, that a parasite inside its host’s tissues will be inhabiting an environment that is itself rigorously controlled by the excretory and osmoregulatory systems of the host animal. Parasites disperse themselves from host to host and, during this transmission, they will be exposed to a variety of physico-chemically different environmental conditions. Many parasites have a direct life-cycle with one host and a single transmission stage. At the other end of the spectrum are parasites, e.g. the strigeid digeneans, which, during a single life-cycle, infect three different hosts and have two distinct transmission stages. We would thus expect the excretory system of parasites to be able to remove the waste products of their metabolism and carry out an osmoregulatory role when the prevailing conditions demand.


Urea Cycle Excretory System Ornithine Transcarbamylase Contractile Vacuole Flame Cell 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Further Reading

  1. Campbell, J. C. (1963) “Urea formation and urea cycle enzymes in the cestode, Hymenolepis diminuta.” Comparative Biochemistry and Physiology, 8, 13–27.CrossRefGoogle Scholar
  2. Howells, R. E. (1969) “Observations on the nephridial system of the cestode Moniezia expansa.” Parasitology, 59, 449–459.Google Scholar
  3. Kidder, G. W. (1967) “Nitrogen: distribution, nutrition and metabolism”, in Chemical Zoology 1. Protozoa, editor G. W. Kidder, Academic Press.Google Scholar
  4. Lee, D. L. and Atkinson, H. J. (1976) Physiology of Nematodes,2nd edition, Macmillan Press.Google Scholar
  5. Read, C. P. and Simmons, J. E. (1963) “Biochemistry and physiology of tapeworms”. Physiological Reviews, 43, 263–305.Google Scholar
  6. Siddiqi, A. H. and Lutz, P. L. (1966) “Osmotic and ionic regulation in Fasciola gigantica (Trematoda: Digenea)”. Experimental Parasitology, 19, 348–357.CrossRefGoogle Scholar
  7. Von Brand, T. (1973) Biochemistry of Parasites,2nd edition, Academic Press. Webster, L. A. (1971) “The flow of fluid in the protonephridial canals of Hymenolepis diminuta.” Comparative Biochemistry and Physiology,39A,785–793.Google Scholar
  8. Webster, L. A. and Wilson, R. A. (1970) “The chemical composition of protonephridial canal fluid from the cestode Hymenolepis diminuta”. Comparative Biochemistry and Physiology, 35, 201–209.CrossRefGoogle Scholar
  9. Wilson, R. A. (1967) “The protonephridial system in the miracidium of the liver fluke Fasciola hepatica”. Comparative Biochemistry and Physiology, 20, 337–342.Google Scholar
  10. Wilson, R. A. (1969) “The fine structure of the protonephridial system in the miracidium of Fasciola hepatica”. Parasitology, 59, 461–467.Google Scholar
  11. Wilson, R. A. and Webster, L. A. (1974) “Protonephridia”. Biological Reviews, 49, 127–160.CrossRefGoogle Scholar
  12. Wright, D. J. and Newell, D. P. (1976) “Nitrogen excretion, osmotic and ionic regulation in nematodes”, in The Organisation of Nematodes, editor N. A. Croll, Academic Press.Google Scholar

Copyright information

© L. H. Chappell 1979

Authors and Affiliations

  • Leslie H. Chappell
    • 1
  1. 1.University of AberdeenUK

Personalised recommendations