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.

  • John Walker
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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    [ 1° ] Defence of remote parts, and of the fubflance of the heart. 13. a. The flrong contractions of the ventricles drives blood into the arterial fyftem. By expanfion of the ar- teries, as well as by the progreffive enlargement of their capacities colleCtively taken, the force of the impetus is di- minilhcd in remote parts, and the exhalants and fecrct- ing veflels perform their functions uninterruptedly. b. Do the arteries take twice the time of the ventricles to perform their fyftole, and is the current hereby render- ed continual in remote parts, as in the exhalants and fe- creting veflels, and without fenfible pulfation as in the veins. c. Synchronous with the contraction of the arteries is that of the cardiac finufes, which, while they are continu- ally open on the venous fide, whereby regurgitation into the veins is l'ometimes produced, (or at leaft accumulation happens in them,) The coronary vein opening into the right finus, is furniftied at its mouth with a valve, with this defign, perhaps, that it may not in any cafe receive greater diftenfion, than what can be produced by the interruption of its own ftream, diftenfion which might be hurtful to the motions of the heart. Neceffity for venous fnufes in the head. 14. a. All the provifion, of finufes and dila- table veins at the heart, does not appear to be iul- ficient to guard fo delicate a part as the brain from the effeCt of reaction, by interruption of the venous current at the heart. h. For this reafon it feems to be, that venous fi- nufes are formed in the head to fuch an extent as to contain, it is fuppofed, one tenth of the whole mafs of blood in the body. Into thefe the veins.