Spiral wave explained

See main article: Autowave reverberator.

Spiral waves are travelling waves that rotate outward from a center in a spiral. They are a feature of many excitable media. Spiral waves have been observed in various biological systems^{[1] [2]} including systems such as heart ventricular fibrillation,^[3] retinal spreading depression,^[4] Xenopus oocyte calcium waves,^[5] and glial calcium waves in cortical tissue culture.^[6]

Notes and References

1. Book: Arthur Winfree

   . Winfree AT. . Arthur Winfree. The Geometry of Biological Time. Springer-Verlag. New York. 2001.

2. Book: James D. Murray

   . Murray JD.. James D. Murray. Mathematical Biology II: Spatial models and biomedical applications. Springer-Verlag. New York. 2003.

3. Davidenko JM, Pertsov AV, Salomonsz R, Baxter W, Jalife J . Stationary and drifting spiral waves of excitation in isolated cardiac muscle. Nature. 1992. 355. 349–351. 1731248. 10.1038/355349a0.
4. Gorelova NA, Bures J . Spiral waves of spreading depression in the isolated chicken retina. J Neurobiol. 1983. 14. 353–363. 6619832. 10.1002/neu.480140503.
5. Lechleiter J, Girard S, Peralta E, Clapham D . Spiral calcium wave propagation and annihilation in Xenopus laevis oocytes. Science. 1991. 252. 123–126. 2011747. 10.1126/science.2011747.
6. Verkhratsky A, Orkand RK, Kettenmann H . Glial calcium: homeostasis and signaling function. Physiol. Rev. . 1998. 78. 99–141. 9457170. 10.1152/physrev.1998.78.1.99.