Studies on the Blood Vessels in the Membranes of Chick Embryos

Abstract

Experiments on the behavior of the blood vessels have with few exceptions been confined until now to tissue in which there are nerves. In all the organs of the body in adult human beings or in animals that have attained full growth, in which such investigations have taken place, the presence of vasomotor nerves has been demonstrated either anatomically or physiologically (1).It is to be expected that in investigations of the reaction of blood vessels in tissues or an organ which is not innervated, the part usually played by the nervous factor can be ascertained. Experiments carried on in such preparations might make possible in a new way the elucidation of questions having clinical interest, as for instance, those arising in arterial hypertension (2) in which hypersensitivity of all vessels is present as well as in arteriosclerosis (3) in which the level of irritability is reduced and finally, in cases of inflammation (4, 5) in which the part played by the nervous system is still the subject of discussion. On the Absence of Nerves in the Yolk-Sack of Chick EmbryosConcerning the occurrence of nerves in the membranes of chick embryos there exist in the literature, so far as we know, no references (6). There are, however, numerous investigations on the innervation of membranes of human beings and other mammals to which we intend to refer by way of comparison. The question whether the umbilical cord and the placenta contain nerves dates according to Schott (7) from the time of Galen. Reports of more recent investigations, to the

The Gaseous Environment of the Chick Embryo in Relation to Its Development and Hatchability

“…C0 2 causes a specific vasoconstriction of the yolk sac blood vessels (Hammet and Zoll, 1928). These blood vessels are without vasomotor nerves (Lange et al, 1930). Although no study to determine the presence of innervation to the chorio-allantoic vascular system has come to our attention, no description of nerves has been found in the electron microscopic studies of the CAM by Leeson and Leeson (1963), Ganote et al (1964) and Skalinsky and Kondalenko (1964).…”

Pathogenesis of Venezuelan Equine Encephalomyelitis Virus Infections in the Developing Chick Embryo

“…The Venezuelan virus is like the Eastern and Western equine viruses in other respects also. The penetration of the virus through the chorioallantoic membrane, which is reported to possess no nervous tissue (Lange et al, 1930), and the destruction of vascular endothelium, with thromboses and hemorrhages, point to a hematogenous spread of the virus throughout the embryo. No grossly visible, specific pocklike lesions were seen, not even on membranes in which the average survival time of the embryo was sufficiently long to have favored the development of such lesions if they are a usual part of the pathologic process.…”