On the necessity for contracting cavities between the venous trunks and the ventricles of the heart : on the use of venous sinuses in the head : on the wonderful provision made for the transition from the foetal to the breathing state, on palpitation, on death and on life, with reflections on the treatment of animals.

  • Walker, John.
Date:
1799
Catalogue details

Licence: Public Domain Mark

Credit: On the necessity for contracting cavities between the venous trunks and the ventricles of the heart : on the use of venous sinuses in the head : on the wonderful provision made for the transition from the foetal to the breathing state, on palpitation, on death and on life, with reflections on the treatment of animals. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    POSTCUI P T. placenta. If the blood pafiing through the duBus arterlsfu completely filled the part of the acrta> which it enters and permeates, this would utterly prevent any blood from be- ing propelled through it from the left ventricle : but the abdominal vifcera, and lower extremities, have need of nutriment alfo ; and part of the blood, fent from the infe- rior cava to the left ventricle, pnffes through the aorta de~ fcehdens ; moreover, as the blood from the inferior cava does not pafs through the right auricle in a diftintt canal, a part of it mixes with the blood from the fupendr cava, as it(palfes to the right ventricle. Thus through two fources is blood, highly nutritive, afforded to the remaining ab- dominal vifcera, and the lower parts of the body ; but from its being mixed with fo large a quantity of carbonated blood, the parts, particularly the pelvis and lowey limbs, are not fo well nourished. Bcfides, the greateft part of this blood palfes off through the umbilical veins to the placenta, to be regenerated. Thus too great a growth in the whole foetus may be faid to be prevented, by the Hint- ing of the parts not immediately effential to life; or ra- ther, by this dinting, the greater quantity of nutriment is determined to the parts mofc effential to its exidence. It is neceiTary that the child breathe on its firft coming into the world. It has immediate ufe for its digeflive powers. Its organs of fenfe are one after another called into play. It mull depend fora time on the bread for fupport ; and, even in the act of fucking, its organs ot fpeech acquire Itrength. In the mean time, the vivifying current, heretofore partially didri- buted through its fyitem, now diddling itfelf more equably* gives ftrength to tliofe parts, which are Ihcrtly to relieve the fond parent from her burden dill pleafing, but becom- ing, at length, too heavy for her arms. In the amufement oi its early years, its organs acquire ftrength, its mental poweis are awakened ; but not, till the age of puberty, is the whole fyitem evolved. Through ripening years, the he&rf (till beats high, the arterial aftioh is drong, the current fets through the venous fyfiem with tonfiderable rapidity, till the veins, at length, fufficientiy dilated, receive, in declining age,with led refiftance, the crimfori ItTeana now fent with diminilhed force, by a heart which fails to give its former youthful llroke, and through arteries now enfeebled, and participating in the ge- neral vveaknefs ; while the mental powers alio fail with in- creafing years, and unequivocally announce the approach of rhat event, which, whenever it arrives, levels every didi.ic- tion of rain man. ■wsasaS-T