Collected papers (Part I.) from the Research Laboratories of the Royal College of Physicians, London, and the Royal College of Surgeons, England / edited by T.G. Brodie.

Date:
1903
Catalogue details

Licence: In copyright

Credit: Collected papers (Part I.) from the Research Laboratories of the Royal College of Physicians, London, and the Royal College of Surgeons, England / edited by T.G. Brodie. Source: Wellcome Collection.

    249/462 (page 187)
    times of stimulation amounted to 4^ hours but still with the same result. From experiments such as this, and from others in .which the time of excitation amounted to more than 6 hours, we conclude that the splenic nerve-fibres cannot be fatigued. Fig. 3. Dog. Morphine and ether. A large splenic nerve has been excited continuously for three hours. This excitation is still continued at the beginning of the tracing. The upper tracing is that of the splenic volume. The second, the blood-pressure taken from the carotid. The next line is a signal line. The zero-abscissa of blood-pressure is 5 cms. below this line. The time record marks seconds. This figure has been reduced to about two-thirds of the original size. We examined histologically some of the nerves which had been excited, and found the vast majority of the fibres were non-medullated, but that there were always a few fine medullated fibres. In one specimen, for instance, we found as many as 50 medullated fibres,' whereas the non-medullated were present in thousands. In reply to a letter from us regarding these fibres Dr Langley kindly wrote to us as follows; “ The medullated fibres peripheral to the solar plexus are partly afferent, partly preganglionic, which have not yet reached their cell- stations (very few of these go to the spleen), and partly medullated post-ganglionic. They all, but especially the last, vary in number in different animals.” “ The external carotid branch of the superior cervical ganglion in the rabbit, which amongst other structures supplies the ear, contains