CHAP. XXXVII. Of the Membrane of the Larynx or Throttle which is the Ligament thereof.
THE Larynx is bound about with a Membrane which is common with the Membrane of the mouth, to be a defence to it both outwardlie and inwardly, and whereby the aire being gently and easily strucken, might make the voice pleasant and moderate. First inwardly, the whole cauitie is compassed & so it is led ouerthwartly to the vpper part of the Larynx, being diuided in the middest of his length it maketh a little cleft. But outwardly it doth partly encompasse the external superficies, and partly it inuesteth inwardly the Gristles and Muscles.
They are steeped in a certaine slimie humidity, partly least the Respiration being warme, smoky and drie, should make the parts drie also, partly that the Epiglottis might be closely ioyned to the glottis and so his exccation might bee hindred, which humidi∣ty is more aboundant within, yet so that in those which are sound it is neither more co∣pious nor more scarse then the instrument of the voice doth require; by it also it is poli∣shed and so the voice is made pleasant and equal, for being moistened with a kinde of humidity it doth familiarly beate the aire, whence the sweetenesse of the voice procee∣deth. This may be prooued by the example of Musitians, who going about to sounde longer Pipes or Trumpets whether they be of Brasse or wood, will somewhat moysten them (haply with their Spittle) whereby the voice may bee made more delectable, else because of too much siccitie the sounde is not onely vnpleasant and harsh, but is made with more difficultie and labour; like as if it be 100 moyst the sound is obtuse, wherefore we saide before the voice is made hoarse by the humours which come out of the Braine into the Choppes.
These Membranes of the Larynx are for the most part thicker and stronger then all the rest. The outward is verie crasse and laxe and as it were rough and rugous; for a∣boue the Epiglottis it is lax and crasse, where it is bound to the sides of the third gristle, and betwixt it and the gristle, especially at the basis, there is a little Fat growing. It is lax, that it may more easily be incurued and turned vpon the Larynx and be mooued in de∣glutition or swallowing, in an acute and graue voice vpward and downward. And it is crasse, somewhat hard also and dense, because by that way meate sometimes halfe chew∣ed, hard and in great gobbits must passe of necessity.
Some there be which thinke that this Membrane is increased with fleshy fibres, and that it becommeth a musculous membrane both in men and beasts to help the lifting vp of the Epiglottis, which Fibres are compassed with a little skin both outward and aboue, least it should be hurt in the passage of the meate.
The internal Coate or Membrane which is more crasse in the cauitie of the Larynx or Throttle then it is in the pipe of the Artery, is soft, stretched and slipperie, beecause the cauitie was to be made polished and smooth; but where the cleft of the Larynx doth close, this Membrane on both sides is by often compressing of it when wee holde our breath, made more hard and callous, and with the substance doth change the colour & waxeth more white. But of this Membrane we haue spoken somwhat before in our Hi∣story of the Rough Artery. Concerning the vessels also and the Glandules of the La∣rynx we shall speake in their proper places.