Development of reflexogenic zone innervation of the human cardiovascular system.

The development of the innervation of the human branchial aortic arches and the heart has been investigated. The early growth of nerve fibres to the 1st, 2nd, 3rd, 4th and 6th aortic arches has been established. Evidence of the transformation of the 1st and 2nd aortic arches and the 4th right one into highly sensitive zones is presented. The order in which nerve connections of the arch regions which develop into reflexogenic zones in a definitive organism are formed is demonstrated. The cranial nerve fibres grow first, and are followed by the sympathetic trunk fibers. Investigations carried out on the extensive material corroborate Koch's hypothesis (1931) that all aortic arches of the embryo develop into reflexogenic zones.