4
THE RESPIRATORY FUNCTION OF
the intrinsic muscles of the larynx is the inferior or re¬
current laryngeal. This nerve, according to our present
knowledge, is purely motor, * and supplies all the intrinsic
laryngeal muscles except the longitudinal tensors, the thyro-
cricoids. It is an anatomical fact that it does not send off
any branches to these muscles until it has reached the
border of the cricoid cartilage. In its trunk, therefore, are
contained two sets of nerve fibers—the respiratory and the
phonatory—which must necessarily be strictly differentiated,
since they are destined for muscles which carry on two
separate and distinct functions. Now, where do these two
sets of nerve filaments come from ; is their origin as dis¬
tinct as their function ; whence do they derive their sepa¬
rate individualities ; which are relatively or numerically the
stronger ?
The sources from which nervous impulses-for the larynx
may be received are the brain, the medulla oblongata, and
the spinal cord. The channels through which they may be
transmitted are the several motor nerves which join the
pneumogastric before tbe recurrent is given off, for we are
aware that from this point the recurrent proceeds to the
larynx without any branch or junction which is in any way
connected with the functions of that organ.
The experimental researches of Krause,f and the clinical
observations of .l.)elavan,J justify the belief that there is a
* We are aware that some have stated, but without giving Experi¬
mental data to substantiate the assertion, that the recurrent contains
sensory as well as motor fibers. We have not the space here to dwell
upon our own experiments to determine this point, but they justify our
remark that the recurrent is “purely motor.’’
■j- “Ueber die Beziehungen der Grosshirnrinde zu Kehlkopf und
Rachen,” “ Sitzungsberichte der kgl. preuss. Akad. der Wissensch. zu
Berlin,” November, 1883.
f “ On the Localization of the Cortical Motor Center of the Larynx,”
New York “ Med. Record,” February 14, 1885.