DOI Page / Citation link:
https://doi.org/10.11588/diglit.4812#0052
42 OBSERVATIONS ON THE
CHAPTER XV.
Of the Plexuses os Nerves.
I.1 VERY nerve of the spinal marrow is joined near its exit, by an arch,
with the nerve above and below it: But the connection os the seve-
ral nerves of the arm, or os the leg, may be considered as chief examples os
plexus.
Eustachius, and several succeeding authors, have given pretty exact, de-
lineations os the outside appearance of these plexuses; but no author has
either carefully traced the nervous fibres in their course through them, or
properly explained the ufes they are intended to serve.
Many years ago, I was at the pains os tracing the sibres of the nerves os
the arm srom their origin in the spinal marrow, to their termination in the
parts os the arm, by ssitting open the sheaths os all the trunks where they
sorm the brachial plexus. I sound, as, indeed, I expected, that in the
plexuses, the fibres os the difserent trunks were intermixed, and that every
nerve under the plexus consifted os sibres os all the nerves, which were tied
together above its origin .srom the plexus*. ^
The joining os the optic nerves not only resembles, in its outside ap-
pearance, the joining os two os the cervical nerves in the brachial plexus,
but it is imposiible to separate them, without tearing the medullary cords ;
so that there appears to me no doubt, that the medullary sibres, srom the
two fides os the brain, are there intermixed. But as this nerve is more
purely medullary than nerves in general are in their course, and soster, be-
cause
* See Tab. XV. Tab. XVI. Tab. XVII.
CHAPTER XV.
Of the Plexuses os Nerves.
I.1 VERY nerve of the spinal marrow is joined near its exit, by an arch,
with the nerve above and below it: But the connection os the seve-
ral nerves of the arm, or os the leg, may be considered as chief examples os
plexus.
Eustachius, and several succeeding authors, have given pretty exact, de-
lineations os the outside appearance of these plexuses; but no author has
either carefully traced the nervous fibres in their course through them, or
properly explained the ufes they are intended to serve.
Many years ago, I was at the pains os tracing the sibres of the nerves os
the arm srom their origin in the spinal marrow, to their termination in the
parts os the arm, by ssitting open the sheaths os all the trunks where they
sorm the brachial plexus. I sound, as, indeed, I expected, that in the
plexuses, the fibres os the difserent trunks were intermixed, and that every
nerve under the plexus consifted os sibres os all the nerves, which were tied
together above its origin .srom the plexus*. ^
The joining os the optic nerves not only resembles, in its outside ap-
pearance, the joining os two os the cervical nerves in the brachial plexus,
but it is imposiible to separate them, without tearing the medullary cords ;
so that there appears to me no doubt, that the medullary sibres, srom the
two fides os the brain, are there intermixed. But as this nerve is more
purely medullary than nerves in general are in their course, and soster, be-
cause
* See Tab. XV. Tab. XVI. Tab. XVII.