Situs

SITUS VISCEItUM INVERSUS (situs trans-versus, s. rarior, heterotaxia), inverted position of the internal organs, such a violation of the general plan of development, in which the internal organs of an individual are not located in their usual place, but on the opposite side of the body, giving a kind of mirror image of the normal position. The inversion may affect the internal organs of all three body cavities - the so-called situs viscerum inversus totalis. It may affect individual cavities and even individual organs, for example, right-sided position of the heart (dextrocardia), inverted position of parts of the intestine, etc.; in these cases, they speak of situs inversus partialis. Complete inversion of the position of internal organs is usually not accompanied by developmental abnormalities of the organs themselves, and the corresponding individuals may be fully functional in a functional respect. Although there are experimental data indicating the possibility of obtaining S. v. i. in frogs and lizards (Spemann) by reverse transplantation of the meso-endodermal rudiment in early embryonic periods of development, however, these data do not allow us to assert that something similar occurs in humans. It is more correct to consider S. v. i. as a phenomenon not associated with heredity. In identical twins and in double monsters, there is also no predominance of cases with S. v. i. in both fetuses. Partial inversion of internal organs affects either the organs of the abdominal cavity (S. v. i. abdominalis), or the thoracic (S. v.i. thoracalis), or individual organs within one or another body cavity. Thus, there are known cases of displacement of the stomach, duodenum and spleen, cases of displacement of the cecum, heart. One can probably speak not only of the inversion of organs as such, but also of the displacement of individual functional-anatomical units within the same organ. This probably includes left-handedness as a variety of S. v. i. from the side of the central nervous system. S. v. i. belongs to the number of rare developmental anomalies. Recognition of this anomaly in complete inversion is discovered without particular difficulty by the usual methods of percussion and auscultation, as well as by radiological studies.

d. grotel.

SITUS VISCERUM INVERSUS (situs trans-versus, s. rarior, heterotaxia), inverted position of internal organs, such a violation of the general plan of development, in which the internal organs of an individual are not located in their usual place, but on the opposite side of the body, giving a kind of mirror image of the normal position. The inversion may affect the internal organs of all three body cavities - the so-called situs viscerum inversus totalis. It may affect individual cavities and even individual organs, for example, right-sided position of the heart (dextrocardia), inverted position of parts of the intestine, etc.; in these cases, they speak of situs inversus partialis. Complete inversion of the position of internal organs is usually not accompanied by developmental abnormalities of the organs themselves, and the corresponding individuals may be fully functional in a functional respect. Although there are experimental data indicating the possibility of obtaining S. v. i. in frogs and lizards (Spemann) by reverse transplantation of the meso-endodermal rudiment in early embryonic periods of development, however, these data do not allow us to assert that something similar occurs in humans. It is more correct to consider S. v. i. as a phenomenon not associated with heredity. In identical twins and in double monsters, there is also no predominance of cases with S. v. i. in both fetuses. Partial inversion of internal organs affects either the organs of the abdominal cavity (S. v. i. abdominalis), or the thoracic (S. v.i. thoracalis), or individual organs within one or another body cavity. Thus, there are known cases of displacement of the stomach, duodenum and spleen, cases of displacement of the cecum, heart. One can probably speak not only of the inversion of organs as such, but also of the displacement of individual functional-anatomical units within the same organ. This probably includes left-handedness as a variety of S. v. i. from the side of the central nervous system. S. v. i. belongs to the number of rare developmental anomalies. Recognition of this anomaly in complete inversion is discovered without particular difficulty by the usual methods of percussion and auscultation, as well as by radiological studies.