CHAP. XVII. Of the Aspera Arteria, the rough Arterie or Weazon.
THe Aspera Arteria or Weazon seeing it is the instrument of voice and re∣spiration, is of a gristly, ligamentous, and wholy various substance. For if it * 1.1 had beene one rough, and continued body with the Larinx or throttle, it could be neither dilated, nor compressed; opened, nor shut, neither could it order the voice according to our desire.
It is composed of veines from the internall Iugular, of arteries arising from the * 1.2 Carotides, and of nerves proceeding from the Recurrent branch, of a double mem∣brane, of which the externall comes from the Peritonaeum; the internall, which is the stronger and woven with right fibers, from the inner coate of the mouth, the which is common with the inner coate of the oesophagus or gullet. And also it consists of round gristles, yet not drawne into a perfect circle, composed in manner of a chan∣nell, and mutually joined together in order, by the ligaments that proceede from their sides and ends.
These same ligaments perfect the remnant of the circle of this Aspera Arteriae, on * 1.3 that part next the gullet; which is thought to be done to this end; that that soft∣nesse of a ligament, might then give place, when wee swallow harder and greater gobbets of meate. Of the two sorts of ligaments which are annexed to the gristles of the weazon, some tie and fasten together the rings or circles, which give meanes both to it, and these circles to be drawne out in length; othersome bring these gri∣stles into a perfect circle, which also yeeld them meanes of dilatation. These liga∣ments cover the inner superficies, but the gristles are placed without, to resist the in∣cursion * 1.4 of externall injuries. But wee must note, that by this communion of the inner coates of the weazon and gullet, wee reape this benefit in the commodiousnesse of the action, that one of these parts being depressed, the other is lifted up, like a rope running in a wheele or pully. For thus whilest the gullet is deprest to swallow any thing, the weazon is lifted up; and on the contrary when the stomacke rises up in vomiting, the weazon is deprest. It is onely one, and that seated betweene the Larinx (from which it takes its beginning) and the lunges in which it ends; first dividing it * 1.5 selfe into two large branches, the right and the left, and besides each of these entring into the substance of the lungs, is againe divided into two others; to each of the Lobes one; and to conclude, these be subdivided into infinite others, through the substance of the Lobes.
All these branches are gristlely even to the ends. They are situate betweene the ends of the Arteria venosa, and the Vena arteriosa, that the entrance of the aire into the heart by the arteria venosa might be speedier, as also the passage out of the vapour, by the vena arteriosa. Thus it hath connexion with these in the ends, or utmost parts thereof, but by the other parts compassing it, with the members from whence it