Page 754
CHAP. XIII. Of the common muscles of the Cheekes and the Lips.
THE muscles which are common to the Cheekes and the Lippes are foure, two on either side called Quadratus and Buccinator, the square muscle and the Trumpeter. The square muscle [tab. 6. fig. 1. 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉. make the circum∣scription,] or as Galen calleth it, the musculous dilatation, or the broade or thin muscle, because it is large and membranous lyeth vnder the skinne of the necke, and also is spred ouer the lower part of the whole face from vnder the mouth. It is a membrane encreased with fleshy fibres which yet doe not arise from any bone: these fibres do assend vpward to the middle of the face, creeping by degrees with a variable course from the regions of the racke-bone of the necke, on the outside of the same where it swelleth most, of the shoulder blades, of the cannell bones and of the brest bones, and so make abroade and thin muscle.
Wherefore if any man shall deny it the name of a muscle, and say it is but a membrane of musculous Nature and substance, or whether he list to call it a muscle, hee shall haue my good will, for it is so thin and so membranous that the ancients did not separate it from the skin but fleyed it off therewith; not accounting it in the number of the muscles, as Galen saith who himselfe was the first that described it, as appeareth in his fourth booke of Anatomical administrations, and in his first book of the dissection of muscles, although he knew it not when he wrote his books de vsu partium. To this membrane many small bran∣ches of nerues are sent from the sinews of the neck & mingle themselues with the fibres; & that is the reason why the membrane in this place is more strongly vnited to the parts then in any place almost of the whole body, and the same dissemination of the nerues causeth thosediuers fiberous passages which are seen in it. For from the breast bone and the middle of the clauicle his fibres run right in the length of the necke, [from ♌ to ζ] and those which beginne from the other parts of the clauicle, from the toppe of the shoulder and from the rest of the parts before named, doe trend obliquely vpward, [from θ to O and H.] and the nearer they are to the spines of the racke bones of the necke the more oblique do they ap∣peare: so that when they come neare the occipitium or nowle of the head they are almost tranuerse: and yet for all that these fibres make no intersections in the neck at all, especial∣ly that are visible: but when they come vnto the Chin where the vpper lip is ioyned with the neather, [betweene H. and ζ.] especially at the lower lip they are so confounded toge∣ther that they can bee no more distinguished. VVe call it the square muscle because it pas∣eth from the vpper part of the necke by the sides of the nowle bone away, toward the eare, & is somtime implanted with fleshy fibres into the root therof, by the help of which [Table 6. is the same with that in the Folio 750.] fibres in those men who haue this position of this muscle their eares, as we haue said, are moued. Sometime vnder the roote of the eare [O] it passeth into the face, and coue∣reth the Masseter muscle of the Iaw, and withall groweth more strongly to the Cheeke bone then other where, insomuch as some haue taken this part of it to be the fifth muscle of the Iaw: and from hence it is inserted into the roots of the Nose. The other side of it is ouerthwart the face. [fromo byu to ζ.] The third side from the top of the shoulder to the brest bone; [from θ by ε to ♌] and this side is very vnequall and as is it were indented. The fourth side to make the quadrature, is from the top of the chinne to the brest bone. [from ζ to.] These muscles doe moue the skinne of the face which is not mo∣ued by the musculous substance of the forehead, the nowle, the eares and the nose, or by a∣ny of their muscles or by the muscles of the eye lids: But rather as the right square muscle draweth and mooueth both the vpper and the lower lippe vnto the right side: so the lest drawes both the lippes obliquely downeward to the left side: and because they cleaue fast vnto the chinne, therefore they helpe much the opening of the mouth. This is that muscle saith Galen in his 1. book de dissect anusculorum, which first of al in those that begin to be af∣flicted with conuulsions is intended or stretched, from whence come those conuulsions which we call Cynicke or Dogge-spasmes, because by the contraction of these, men are constrained to writh and grinne like Dogges.
The fibres of this muscle Galen in his first booke de Anatom. Administ. counselleth the Chirurgion to be well aduised of, because of their incisions which sometimes are very ne∣cessary in this part. For ignorant Chyrurgions not knowing their course haue by large transuerse sections deuided them so farre that the cheekes haue flowne upward from the skin vnderneath them.