A practical treatise on the management and diseases of children / by Richard T. Evanson and Henry Maunsell.
- Evanson, Richard Tonson, 1800-1871.
- Date:
- 1843
Licence: Public Domain Mark
Credit: A practical treatise on the management and diseases of children / by Richard T. Evanson and Henry Maunsell. Source: Wellcome Collection.
Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)
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![of the left ventricle become almost four times as thick as those of the right — a change which rapidly proceeds after the obhteration of the ductus arteriosus, and the closure of the foramen ovale, when the left ventricle has the sole conduct of the circulation through the system. The parietes of the heart are softer and paler than in after life, when the relative bulk is less, but the texture firmer, and colour deeper ; this organ being then called upon to propel its contents with greater force, as they have to traverse a longer space. In the infant, the large volume but feebler power of the heart fits it for the propul- sion of a larger quantity of blood, but through a less distance ; while the peculiar irritability of this, as well as the other hollow muscles, during infantile life, ensures more active contractility, and so, more rapid action, suited to the constant demand for fresh supply, Ac- cordinglj^ we often find the pulse in the infant, like the respiration, nearly double in frequency that of the adult, varying from 120 to 140 oeats in a minute.* The part of the nervous system more immediately connected with the class of organs which we have just been considering, should naturally be in a high state of development, to allow of that fulness of function which we have seen these organs to possess: and accord- ingly, we find the ganglions, or system of the sympathetic nerve, very perfectly formed at birth ; while the brain, and its nervous con- nections, on the contrary, are very imperfectly formed, though largely developed — m.ore especially the brain itself We now come to the consideration of the second class of organs, — those of animal life, or relation to external objects ; and here we shall find remarkable changes manifested in the advance of organs from a state of essential imperfection, to one of completeness — this advance in organization, and successive development of function, constituting the most interesting eras of infantile life, looked forward to with * The pulse in the child varies so much in different individuals, and according to different circumstances, that it is very difficult, if not impossible, to assign a rate of frequency according to the age. Some general conclusions may, however, be come to, and a proximate, if not accurate, guide thence derived in disease ; but the most experienced practitioners are most cautious in drawing conclusions from the frequency of the pulse in the young child. The influence of position is very re- markable— a change from the recumbent to the sitting posture at once adding greatly to the frequency of the pulse — much more when the attitude is erect and the child in motion. We have often found the pulse, which at night (during sleep) was 80, full and steady ; up to 100 or even 120 during the day, small and hurried — and that in more grown children (six or seven years of age), and in perfect health. While, on the other hand, in very young infants (under six months old), the pulse may continue quite unaffected during dangerous illness —particularly serious ab- dominal affections. The most general conclusion which our observations have enabled us to make, is, that the pulse is not most frequent immediately after birth, but at the age, or at least the time of teething ; and that it thence gradually dimi- nishes in frequency. This view accords with the experiments of Dr. J. Gorham, who assigns 130 as the mean number of the pulse from five months to two years old; and 107.63 from two to four years of age; whence the number continues almost the same up to the tenth year. See the Medical Gazette for 1837- [Note to 4th Edition.]](https://iiif.wellcomecollection.org/image/b21118346_0023.jp2/full/800%2C/0/default.jpg)
