354
Z. R Y C H T E R
E. Position of the Recurrent Nerve in Various Aortic Arch Patterns
In normal chick embryos, the recurrent nerve runs bilaterally below
both the 6th aortic arches around the beginning of the ductus arteriosi
(Botalli). Since Stephan (1952) has suggested that traction exerted by
this nerve is important for the histogenesis of the 6th aortic arches,
Rychter and Lemez (unpublished data) traced the position of the nerve
after elimination of the 6th aortic arch alone and in combination with
other arches; the aim of these investigations was to ascertain whether
the nerve in any way deforms the course of the vessel which runs below.
The position of the beginning of the recurrent nerve after step-by-step
elimination of the right aortic arches (Fig. 24a-d) or left aortic arches
(Fig. 24a'-d'), starting with the 6th, is not, in principle, different from
that described by Brenner (1883) in various congenital anomalies of the
FIG. 24. Position of the recurrent nerve after elimination of various aortic arches.
GN = ganglion nodosum n. vagi; n r = n e r v u s recurrens; n X = n . vagus; Th=glandula
thyreoidea. Number of aortic arch in inverted commas indicates incomplete arch. The
asterisk in (6) indicates the cord from the original right pulmonary artery, which is
substituted by a remnant of the suppressed right 4th aortic arch and begins, therefore,
from the ascending aorta.
Z. R Y C H T E R
E. Position of the Recurrent Nerve in Various Aortic Arch Patterns
In normal chick embryos, the recurrent nerve runs bilaterally below
both the 6th aortic arches around the beginning of the ductus arteriosi
(Botalli). Since Stephan (1952) has suggested that traction exerted by
this nerve is important for the histogenesis of the 6th aortic arches,
Rychter and Lemez (unpublished data) traced the position of the nerve
after elimination of the 6th aortic arch alone and in combination with
other arches; the aim of these investigations was to ascertain whether
the nerve in any way deforms the course of the vessel which runs below.
The position of the beginning of the recurrent nerve after step-by-step
elimination of the right aortic arches (Fig. 24a-d) or left aortic arches
(Fig. 24a'-d'), starting with the 6th, is not, in principle, different from
that described by Brenner (1883) in various congenital anomalies of the
FIG. 24. Position of the recurrent nerve after elimination of various aortic arches.
GN = ganglion nodosum n. vagi; n r = n e r v u s recurrens; n X = n . vagus; Th=glandula
thyreoidea. Number of aortic arch in inverted commas indicates incomplete arch. The
asterisk in (6) indicates the cord from the original right pulmonary artery, which is
substituted by a remnant of the suppressed right 4th aortic arch and begins, therefore,
from the ascending aorta.