The Cardio-Pneumatic Movements

When the heart begins to contract, blood will be flowing into the chest as before, but the systolic pulse will not have reached the vessels at their outlets from the chest. The total result will therefore be that at this instant more blood will be within the chest than was the case before the commencement of systole, and in consequence of this air will leave the chest. As soon, however, as the chest is emptied by the systolic gush of blood, air will re-enter the cavity with a rush, and only leave it again when the diastolic inflow of blood has made itself felt. In addition to these, many other factors are believed by Landois to influence the movements, only one of which it is necessary to mention here. According to this observer, whenever the pulmonary arteries are distended by a systole they compress the air cavities, and cause an outflow of air from the mouth. The cardio-pneumatic movements may be shown in a variety of ways, and one of the most striking is by means of the manometric flame. The mouth is brought in connexion with the capsule of a manometric flame, while the nostrils are closed and