What is the Heart?
It is a most noble Part, being the Fountain of Life, and the first Original of the Motion of all the others; on which account it is call'd Primus vivens, & ultimum moriens; that is to say, the first Member that begins to live, and the last that dies.
What Parts are to be consider'd in the Heart?
Its fleshy Substance, with all its Fibres turn'd round like the Skrews of a Vice; its Basis, Point, Auricles, Ventricles, large Vessels, Pericardium and Ligatures or Tyes: The Basis is the uppermost and broadest part; the Point is the lowermost and narrowest part; the two Auricles or small Ears being as it were little Cisterns or Reservers, that pour the Blood by degrees into the Heart, are situated on each side above the Ventricles. The Ventricles, which are likewise two in Number, are certain Cavities in its Right and Left Sides. The large Vessels are the Aorta or great Artery, and the Vena Cava together with the Pulmonary Artery and Vein. The Pericardium is a kind of Bag fill'd with Water, wherein the Heart is kept; which is
fasten'd to the Mediastinum by its Basis, and to the large Vessels that enter and go out of its Ventricles.
What are the Terms appropriated to the continual beating of the Heart?
They are Diastole and Systole, from whence proceed two several Motions, the first whereof is that of Dilatation, and the other of Contraction, communicated to all the Arteries which have the same Pulse.
To what use serves the Water contain'd in the Pericardium?
It prevents the drying of the Heart by its perpetual Motion.
What are the Lungs?