Injuries of nerves and their consequences - Reflex Sympathetic ...

NEURO-PHYSIOLOGY. 31
which minister to pain, touch, the thermal sense, motion,
calorification, and nutrition.
I do not think it desirable to enter as largely into these
subjects as they would be dealt with in a physiological
treatise, but I cannot avoid some reference to such portions
of their physiology as either aid us to comprehend
and relieve nerve wounds, or as are set in new or clearer
of these accidents.
light by the phenomena
Trophic nerves. — The question which most often presents
itself for answer to the ueuro-pathologist
is as to
the existence or non-existence of nerves directly affecting
the nutrition of the tissues, apart from the changes
induced
in them by the section or irritation of vaso-motor
nerve fibres. Without attempting to treat fully of this
matter, for which, indeed, the physiological groundwork
is still deficient, I shall content myself with stating the
impressions in this direction which a large
experience of
nerve wounds has left
upon my mind.
When the physiology of the vaso-motor nervous system
was first elucidated by tbe labors of Bernard, Brown.
Sequard, Schift', and others, it was supposed that it would
enable us readily to explain the many obscure phenomena
which arise out of nerve wounds ;
but despite the able
arguments of Ilandfield Jones* and some other observers,
this hope has gradually faded away, and it is now gen-
admitted that we must seek elsewhere for a
erally
satisfactory explanation of the facts in question.
The eflects of injuries or sections of these nerves can
be only to cause either contraction or dilatation of vessels,
or to put a stop to the pulsatile movements which have
been seen in minute vessels in many parts of the animal
economy. These alterations, with the consequent changes
in blood supply which they bring about, may be direct
* St. George's Hospital Keports, 1868, p. 89 et seq.