WHOLE (coeloma; Greek koiloma deepening; synonym: deyterotsel, the metapurpose) — the perigastrium which is formed in the course of an embryogenesis between a body wall and internals.
C. is available only for those animals, at to-rykh in the course of an embryogenesis the average germinal leaf — a mesoderm is formed (see). The animals having C., combine under the name of coelomic, or coelomate (Coelomata). The highest Protostomia (ekhiurida, mollusks, sipunkuli-da, annlides), shchupaltsevy, pogonofor, shchetinkochelyustny and vtorichnoroty concern to them (semi-chordates, erinaceouses and chordates, including vertebrata). The most important characteristic of C. restriction with its own coelomic epithelium of the mesodermal nature is (a mesothelium, tselotely). C. contains coelomic liquid. In the course of embryonic development of the person Ts. participates in formation of a cavity of a pericardium, peritoneal and pleural cavities.
There are several theories of an origin of C. According to the ente-rotselny theory which is put forward in 1874 by I. I. Mechnikov and added with O. R. Hertwig and R. Hertwig in 1881 whole develops from hollow karmanoobrazny outgrowths of primary gut. On a не-фроцельной of the theory, C. it is homologous to expanded channels protonefri-diyev (see Kidneys, a comparative anatomy and physiology). The shizotselny theory is most recognized, to-ruyu many scientists, including
V. N. Beklemishev and N. I. Livanov consistently developed and supplemented. According to this theory of C. results from growth and epithelization of interfabric sites of primary perigastrium.
Functions C. at various types of animals are various. At the lowest animals the main function C. — basic since the liquid surrounded with an epithelial cover plays a role of incompressible, but easily changing a form «hydroskeleton». Besides, C. and coelomic liquid participate in maintenance of constancy of internal environment of an organism — its salt, water, gas, temperature modes. Besides, the person and the highest animals have remains of C., being a part of these or those structures, perform protective and other specialized functions.
Bibliography: B e r K. M. Istoriya of development of animals, t. 1 — 2, M., 1950 — 1953; To N about solution e And. G. Short sketch of embryology of the person, JT., 1959; Sh m and d G. A. Embriologiya's t of animals, p.1, M., 1951.
Yu. P. Sergeyev.