The causes and nature of the vascular kind of bronchocele, and of the pulsations and palpitations termed anæmic / by Thomas Laycock, M.D.

  • Laycock, Thomas, 1812-1876.
Date:
[1863], [©1863]
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Licence: Public Domain Mark

Credit: The causes and nature of the vascular kind of bronchocele, and of the pulsations and palpitations termed anæmic / by Thomas Laycock, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    vascular and cardiac symptoms, there are, however, others of import- ance observed to be associated with them and the enlargement of the thyroid, which are either laryngeal or pulmonary, or both, and which indicate an aiFection of the vagus system. I formerly pointed out cases of paroxysmal exophthalmos, accompanied with sudden enlargement of the thyroid body and suffocative difficulty of breathing, which belong to this class.^ Hence the necessity of examining the nerves of the thyroid gland in relation to the anatomy of the vagus and of the cardiac motor centre. Obviously, the nervous system of the thyroid body must be in relation to its functions, and these in relation to its structure. Now, it belongs to the class of ductless glands; and being made up of two lateral halves, as distinct from each other probably as the kidneys or suprarenal capsules, and only integrated because of their close con- tiguity to the median line, it is symmetrical, so that the more proper term would be thyroid glands. The fundamental structure, or the element essential to function, consists in clusters of closed vesicles, Avhich contain an albuminous or gelatinous fluid. These clusters are contained in the two lobes or glands symmetrically placed, with a mesian column connecting them, and which divide and subdivide like those of a conglomerate gland. A thin fibrous capsule, continuous with the sheath of the cervical glands, encloses the whole, and each lobe is separated from the others by fibrous septa, which are pro- longations of the general capsule. The arteries are in symmetrical pairs, and are inferior and superior. The inferior arise from the subclavian, at a point just opposite to the origin of the vertebrals, which, it must be remembered, supply both the spinal cord and the cerebellum, and posterior lobes of the hemispheres; the superior arise higher up from the external carotid, very near its bifurcation with the internal carotid, which supplies with blood the anterior and middle cerebral lobes. The capillaries form a continuous network, at least throughout each half of the gland. The nerves, like the arteries, are symmetrical, and are supplied from the recur- rent and external laryngeal nerves, both being branches of the vagus; but it is most important to observe also that a plexus, derived from the middle cervical ganglion of the sympathetic, proceeds along the inferior thyroid arteries, or those derived from the subclavian. The theories as to the functions of the thyroid glands have all, without exception, omitted any reference to its sources of innervation. Dr Parry believed it served as a diverti- culum for the blood when the brain is supplied with too much or too forcibly ; Mr Simon entertains a like opinion, which he thinks is established by the peculiar relation of the thyroidal arteries, at their point of origin, to the encephalic arteries. And, certainly, their size also favours the hypothesis, for their united capacity is said to be equal to that of the basilar arteries. There is no proof, however, that the mechanical distention of the gland, 1 Ed. Med. Journal, loc. cit., p. 685.