Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them]

Chapter 20 On the Cartilaginous Substance Which Is Ascribed to the Base of the Heart, Or the Bone of the Heart

[Introduction]

This figure illustrates the roots of the great artery [aorta] and the arterial vein [truncus pulmonalis] in a perfunctory way, separated from all connected bodies and parts and closely resembling two circles. 1 The letter A marks the root of the great artery, B the root of the arterial vein. C [tunica externa] identifies the connection by which the vessels are attached to each other at their very beginning. 2 This connection, which is essentially cartilaginous, should not be looked for in this rough figure, but in other figures of the sixth book, most of all the eighth and tenth, which should be looked over in passing, together with the indices to the characters. But it would be cumbersome for me to print the same plates numerous times in several places.



Lest perhaps we seem to have omitted any bone in the present book, we thought we should at this point make mention of the bony substance of the heart.

The human heart has no bone 3
Galen stated that a bone of unusual size had been cut from the heart of an elephant by one of his friends, and he says that there is a bone in the hearts of great animals and a cartilage in the hearts of lesser ones. 4 But so far I have found a true bone in no heart, human 5 or otherwise, and in that place where Galen located the bone of the heart I observe a cartilaginous substance which in my view, at least, is nothing but the roots of the great artery (below B, C, and D [valva aortae] in fig. 10, Bk. 6) and the arterial vein (below E, F, G which mark the membranes [valva trunci pulmonalis] in fig. 8, Bk. 6) taking their origin from the heart.

Cartilaginous substance of the heart
These roots [conus arteriosus] in which the bases of the membranes [valva] are located and which


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are responsible for preventing the reflux of materials [sanguis] from those two vessels into the heart, are much harder than the remaining substance of those vessels, so that the roots seem to participate somewhat in the nature of cartilage. In cattle, it sometimes hardens 6 in the same way we have previously stated that the rib cartilages of quadrupeds revert into white, friable bone covered by cartilage on the outside like a membrane. These roots of the vessels are contiguous (C) [tunica externa] just as if you joined two circles (A and B) at a point and made them tangential to each other, so that the right circle would be the root of the arterial vein [truncus pulmonalis] and the one on the left (which is larger) the root of the great artery [aorta]. The point where the circles [tunica externa] join would be the place where these vessels join their circles and are fused together, 7 and where the best portion of cartilage would be, which is oblong and more or less rounded: the entire location where those roots join, and the remaining portions of the circles, would be resected. Hence, so far as I am concerned, one could call these roots 8 either coronary cartilage or bone, provided one look carefully into their nature and not, like the followers of Galen who quite negligently explain his opinions, be so dull-witted as to convince himself that the bone of the heart is shaped like a L or u.


Anatomists’ errors
Those who attempted to write about the human body after Galen consider a certain structure in the base of the heart to be a bone [os cordis], and compare it to the one placed before the top of the larynx (fig. 1 and 2, chapter 13), called u(oeidh/j, hyoid, from the u shape. Nor did it suffice those people so to invent a bone in the base of the heart: worse yet, they added that the base of the heart, and therefore even the entire heart, is braced by it no differently than the base of the tongue is braced by that bone [os hyoideum] which is placed before the larynx. For they believe that the heart is braced and moved by such a bone, without even considering whether a heart possessed of such a bone could be propped up by it just as an iron rod would support a bed in the air: no sooner would it be attached to the bed than both would fall down. At the same time, we cannot deny that the connection of the four vessels of the heart to their adjacent surfaces does somewhat support the heart.



The fraudulence of physicians and druggists 9
Let us have done with the fabrications of such people and ignore the negligence with which they pompously prescribe for those with heart ailments (so they believe) a draught compounded from the bone of a stag’s heart 10 mixed with some jewels or other and gold. 11 For in fact a stag’s bone is no different than that of a calf, a dog, or a pig, to wit, the cartilaginous roots of the great artery and the arterial vein. And that ossicle which the druggists’ shops have in the past falsely told me is taken from the hearts of stags is I believe nothing else than the larger ossicle 12 of the hyoid bone of a lamb, which is continuous and very like a lambda, l, except that the right leg cuts diagonally across the left like this [Sheephy.gif ], and one leg is shorter than the other—as a sheep’s tongue will show clearer than day whenever it is served at table. 13 When we take up the dissection of the heart in the sixth book we shall describe the method by which the cartilaginous roots of these vessels are investigated.


Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them]