Mikrokosmographia a description of the body of man. Together vvith the controuersies thereto belonging. Collected and translated out of all the best authors of anatomy, especially out of Gasper Bauhinus and Andreas Laurentius. By Helkiah Crooke Doctor of Physicke, physitian to His Maiestie, and his Highnesse professor in anatomy and chyrurgerie. Published by the Kings Maiesties especiall direction and warrant according to the first integrity, as it was originally written by the author.

CHAP. XV. Of the Muscles of the lower Iaw.

OF the two Iawes, the vpper as well in man as in all other creatures is immooue∣able, excepting the Parrot and the Crocodile, the lower is necessarily mooued for the breaking and preparing of our meate, and the articulation of the voyce. * 1.1 The motions of this lower iaw are of two kindes, simple and compound, the simple motions are sixe, and the compound but one. The sixe simple motions are vpward and downeward, to the right hand and to the left, foreward and backe∣wards. The compound motion is made of the right and the left the forward and the backeward, whereby the iawes seemeth to bee carryed round. The motion vpward * 1.2 is performed by the temporall muscle, downeward by the Digastricke; to the right hand and to the left by the first grinder called Mansorius primus: backeward by the other man∣sorius or the muscle that lurketh in the mouth: forward by the fifth paire.

The motion vpward and downeward is to bite, or to share or cut: the motion to the sides whether it be to the right hand or to the left, forward or backeward is to grind: for * 1.3 the meate falleth vpon the teeth of the lower iaw, as vppon the moouing stone of a Mill. For as in a Mill the weight of the vpper stone breaketh the corne vppon the lower: so the meate is ground betweene the vpper teeth which resemble the fixed or immoue∣able stone of the Mill, and the lower teeth set in the lower iaw which resemble the moue∣able stone. And therefore these. Muscles are called Molares, that is, the grinders, and because their act is called Mastication or chewing, therefore they are called Masticatorij or Mansorij, that is, the chewers. VVherefore the Mouth is opened, shut and drawne in compasse by fiue muscles on either side. The first is called Temporalis, Galen de dissect mus∣cularum 6. cals it Crotaphita [tab 6. fig. 1. and 2. ^•. tab. 4. fig. 2. his circumference is noted by ^NNN his fleshy part by ^QQQ, couered yet with the pericranium at ^• & the Membrane retra∣cted * 1.4 or drawne backe at ^P] we call it the Temple Muscle, because it is seated in the temples that is in the side of the head at the vpper and forepart of the Eare. This muscle is strong and stiffe; and the largest of all the rest; filling all the cauity of the temple bones. If ariseth [tab. ••. fig. 2. α. β. γ.] with a broade fleshy and semicircular beginning or originall from the first bone of the vpper iaw, of the forehead, of the forepart of the scull, of the temples and the Sphenoides or wedge bone, and becomes by degrees more fleshy, & growes narrow vn∣der the voke bone called Iugale which runneth vpon it and about it ouerthwart [tab. 6. fig ••. ^•] and to which it groweth a litle for better defence, and is inserted with a short neruous and exceeding strong Tendon to the sharpe [tab. 7. fig. 4. ^b.] processe of the lower iaw im∣bracing it very firmely with his large armes.

The strength of this muscle (by which sometimes a man is able to bite a strong naile in sunder, and we haue known a man therwith to guide a great bell being rung to the height) * 1.5 is caused by his fibres: for all of them as it were from three parts of a circle runne vnto his center, which is to be obserued in the dilatation of the wounds of this part and must some∣times necessarily be made, as also because of the appostemations of these Muscles that the * 1.6 Chirurgion may know how to make incision according to the rectitude of his fibres, lest if he wound them ouerthwart, their vse and action should perish, and the life saith Columbus with it.

The vse of this Muscle together with his fellow is, if they draw directly vpward to lift vp the lower iaw to bind it strongly and to shut the mouth. But if one of them draw alone, then is the traction of the iaw oblique, although Vesalius thinketh that this oblique trac∣tion is made by three muscles, the temple muscle, the masseter or chewer and that that lies * 1.7 hid in the mouth; whence it is that some make three masseters, but Hippocrates in his book de Arte, mentioned but two. This Muscle the Ancients and amongst them Hippocrates and Galen haue preferred before many others and admired in his composition the wisedome and prouidence of the Creator in making it diuersly according to the diuers vse of the creature.

Galen also in his eleuenth booke of the vse of parts and the third chapter, sheweth ••ow these muscles if they be wounded do especially bring conuultions, feauers, deepe and dangerous sleepines, and light frenzies. And Hippocrates saith, that the wounds of the tem∣••les are mortall. The reason of these accidents may be because they are neare neighbours ••nto the braine, there being onely the scull betweene, and that parted by the coronall su∣ture * 1.8 or crown seame: as also because of the many and large Nerues which are disseminated ••rought it as Galen hath obserued in the former Booke and the seuenth Chapter. This

muscle hath 3. nerues on either side inserted into him: two from the third coniugation, and the third harder from the fift coniugation to giue him the greater strength, for the more nerues and the harder a muscle hath, the stronger it is to performe his action. No maruell therefore if vpon the wounding or concussion, convultion yea death it selfe doe follow.

And hence it is that Hippocrates thought the luxation of the neather Iaw was often∣times deadly, because thereby this Muscle is distended, and in his Booke de artic•••••••• hee sayth, that vnlesse the bones of the neather Iaw be ioynted againe after their luxation the life wil be in great ieopardy, by reason of the continuall Feuers and dull and drowsie slee∣pinesses which follow thereupon: for these muscles if they be altered from their naturall * 1.9 disposition, and intended or streatched are soporiserous: Wherefore Nature for their better defence hath couered them first with a strong, thicke and hard membrane, which is * 1.10 the Pericranium or scull-skinne, by reason whereof the muscle on the outside looketh li∣uid, for his inner part which cleaueth to the bone is altogether fleshy, because the bone in that place is not couered with the Periostion. And because a part of the Pericranion runneth ouer this Muscle, some haue described it with two tendons, one inward and ano∣ther outward.

Another defence it hath is this; that the lower part which is neruous is walled with * 1.11 the Iugall or yoake-bone, that the nerues (sayth Galen in the 8. Chapter of his 9. Booke de vsu partium) should not be hurt, so as this bone seemeth to haue been made onely for the behoofe of this muscle.

Thirdly, the Tendon of this Muscle is defended aboue and below with flesh that it * 1.12 might be better secured from outward iniuries. The difference of these Muscles accor∣ding to the variety of creatures is after this manner: First of all in men they are the least * 1.13 and least neruous ordinarily; among beastes they are the least in Apes, I meane accor∣ding to their proportion. They are greatest and largest, as also most neruous in such beasts as haue their teeth set like a Saw, as Lyons, VVolues, Dogges and such like. There * 1.14 are other creatures wherein they are very large but not so neruous; large not so much for the strength of the action, because those great creatures doe feede mostwhat vppon the earth, but that they might bee proportionable to the magnitude of the lower Iaw, such are Asses, Horses, Oxen, Cammels and such like, as we may reade at large in Galens elea∣uenth Booke de vsu partium and the 2. Chapter.

They are least in men both because our neather Iaw in respect of other creatures is the very least, and beside, because our teeth are giuen vs only to breake our meate and for * 1.15 no other vse: for a mans fortitude consisteth not in the strēgth of his Iawes, neither doth hee thereby curbe and keepe in awe the other creatures but by reason and by his handes. Notwithstanding they are the greatest of all the muscles of the Iaw, because they almost sustaine it and lift it vp as if it hung and depended only vpon them.

The second Muscle of the lower Iaw is called Mansorius primus, Masseter & moliter, * 1.16 names all taken from the vse of the Muscle which is called Manducation or chewing, and therefore wee may well call it in our English the Chewing or the grinding muscle. His position is in the Cheeke [tab. 6. fig. 2. and tab. 7. fig. 3. I ta. 4. fig. 2. V] and it hath a double head, one neruous proceeding from the ball of the cheeke [tab. 6. fig. 2. ^Λ] vnto the suture where the Iaw-bone meeteth with a part of the Iugall or yoake-bone, and passeth along vnto the vtmost angle or the Iaw which wee call his acute or sharpe processe; the other head is fleshy and passeth from the yoake-bone [ta, 6, fig, 2, ^x and ta, 7. fig, 3, at ^•] toward the chinne, and is implanted very strongly [table 6, figu, 2, μ] with a broad insertion to the whole latitude of the lower Iaw, so as it representeth, saith Galen in the 4. chapter of his 11. Booke de vsu partium, the corner of a blunt or obtuse triangle, the top whereof is neare the ball of the cheek, [Λ] one side toward the end of the yoake-bone [from Λ to ••] another side toward the lower Iaw [from χ to μ], and the third and last as it were a Basis ioyneth both the forenamed sides to all the parts of the lower Iaw, being extended or streatched according to his length.

The Fibres of these heads do intersect themselues like this figure χ; and thence it is that * 1.17 they moue the Iaw as well on both sides as also forward and backeward (for there is a di∣uers motion required in chewing or grinding the meate) and in compasse: for as the vse and action of the temporall muscles was vehemently to ioyne the teeth & the two iawes together, and so to breake whatsoeuer should light between them: so the action of these

chewing or grinding muscles is to leuigate or shred small the meate that is before broken by the temporall muscles. To this action the tongue doth not a little helpe, which like a hand turneth and returneth the meate in the mouth that all his partes may come vnder the Breake; which motion of the tongue is performed by a muscle of the Tongue called Linguae Masticator or the Tongues Chewer, and not onely so, but also the muscles of the cheekes are of great vse toward the performance of the foresaid worke.

The third payre of muscles [Tab. 7, fig. 4. neere to ^B] is situate vnder the temporal mus∣cle in the lower part of the cauity of the Temple bones, and taketh his beginning partlie * 1.18 from the vpper and vtter parts of the processes called Allformes or like vnto wings which are sharpe and vnequall; and partly from the roofe and sharpe top or height of the bone called Sphenoides or the wedg-bone, which in the cauity of the temples looketh directlie against the yoke-bone, where it hangeth ouer a large rift made by the same Sphenoides & the greatest cheeke-bone.

The originall or head of this muscle is partly neruous and partly fleshy, and hauing gotten this fleshinesse it is led obliquely backeward and is inserted into the necke of the lower iaw, and into the inside of his head. His vse is to mooue and lift forward the Iaw, as the next that followeth mooueth it backeward.

The fourth muscle is another Mansorius which Galen in his fourth Booke of Anato∣micall * 1.19 administrations the fourth Chapter and diuers other places, calleth the muscle lurking in the mouth, [Tab. 7. fig. 4 O] because it lyeth hid in the great bosome of the in∣side of the Iaw. This muscle is thicke and short, and ariseth very neruous from the inward cauity or hollow pipe of the wingy processes of the wedge-bone called Sphenoides; after∣ward becomming fleshy, large and thicke it descendeth with right fibres, and is inserted with a strong neruous and broad tendon to the inner and backe-part of the lower Iawe where the roughnesse is, and where the bosome or hollownes is fashioned that it might not take vp too much roome about the Almonds of the throate. And this muscle (sayth Galen) helpeth the temporall muscle to which it groweth strongly neere the production and insertion of his tendon; for it draweth the Iaw inward and vpward, and shutteth the mouth, because it is a matter of labour to draw a heauy thing vpward, and to breake and grinde a hard substance: besides when the Iaw is brought forward it draweth it backward againe. The fift Muscle called Graphioides or Digastricus, double bellied [Table 7 figure 3, ^OP and figure 3, ^NO Table 6. figure 2 ^O] is thinne and small; arising membranous and very broade from the Apendixe called Styloides (from whence Galen called it * 1.20 Graphioides, because the Ancients vsed to write vpon waxen Tables with a Probe which they called Stylus) and immediately becommeth fleshy and round and passeth vnder the lower part of the vpper Iaw and the eare, and in the middest where it is curued or croo∣ked at the turning of the lower iaw it looseth his flesh and becommeth Neruous: and a∣gaine reconering his flesh is inserted into the middle of the iaw fast by the lower part of the chin, where the inner bone becommeth a little rugged for his better insertion, and where both the Muscles of each side do meete; albeit about his middest it cleaueth to the bone called Hyoides. There is also in this place a kinde of forme of a Pulley; for because these Muscles do not arise from the lower parts of the necke but rather from the vpper, they could not mooue the Iaw downward vnlesse they had bene wound about the lower angle of the lower Iaw, as it were about a Pulley.

The vse of this paire of Muscles is to draw the Iaw downward, & so to open the mouth and by consequence to draw the tongue toward the throate: but if one of them onely do * 1.21 mooue, it leadeth the Iaw obliquely to his owne side. It was called Digastricus because it hath two Venters or Bellies, being fleshy in the beginning and in the end, and in the middle [Tab. 7. fig. 3 betweene ^O & ^P fig. ••. between ^N and ^O] neruous or tendinous (which is peculiar to this and to the second paire of muscles of the bone Hyoides [tab. 7. fig: 3, V, * 1.22 V] and to the fift proper paire of the Larynx or throttle) partly for more strength, partly that it might not take vp too much roome because the place is but narrow, and there are many Instruments to fill it vp, especially the muscles of the tongue and of the Hyois: and therefore also they were made small and thin, round and long, their motion beeing but easie. for the Iaw fals downward with his owne weight, and therefore needed no strong retractor.

Finally, because a part of the square muscle (which with Galen we reckoned among the muscles of the cheekes) groweth more strongly to the bone of the lower Iawe, the right * 1.23

and the left meeting at the middle of the chinne to draw the same downward; therefore Arantius (who did not acknowledge the third paire aboue named) maketh it the fift paire * 1.24 of the Iaw, and sayeth, that this portion or part of the square muscle together with the 4. paire called the Digastricks, do open the mouth and draw the Iaw downwards, yet so, that it is more directly drawne (without the motion of the cheekes) by the fourth paire; but by this fift paire as he accoūteth them, the iaw is wrested obliquely together with the cheeks and the lovver lip side-vvard if but one of them moue; if they mooue together, then it in∣clineth it to neither part but leeadeth it tovvard the throttle.

Notes

• * 1.1

  Only the Pa∣rot and the Crocadile moueth the vpper iaw.
• * 1.2

  Sixe similar motions and what they are
• * 1.3

  The vse of these motions
• * 1.4

  Fiue muscles
• * 1.5

  A strange strength of a mans iaw.
• * 1.6

  A good ob∣seruation for Chirurgions.
• * 1.7

  Vesalius his o∣pinion of the oblique tra∣ction of the iaw.
• * 1.8

  Hyppocrates.
• * 1.9

  The dangers of the falling of the iaw.
• * 1.10

  How nature hath defen∣ded these mus¦cles.
• * 1.11

  The 2. defēce
• * 1.12

  The third.
• * 1.13

  In what crea∣tures these muscles are greatest.
• * 1.14

  In what crea∣tures least.
• * 1.15

  Why least in men.
• * 1.16

  The 2. mus∣cle of the lo∣wer iaw cal∣led the grin∣ders
• * 1.17

  His fibres.
• * 1.18

  The 3. paire of muscles of the lower iaw
• * 1.19

  The 4. muscle of the lower Iaw.
• * 1.20

  The Fyfre and last muscle of the lower iaw His variable substance.
• * 1.21

  The vse of these muscles together.
• * 1.22

  What muscles haue 2 bellies
• * 1.23

  The reason of Arantius his opinion.
• * 1.24

  The vse that Arantius limit∣teth.