CHAP. XXVII. Of the Muscles of the Hand in generall.
GAlen considering the admirable frame and structure of the Hand, because it is as he sayth the Instrument of Instruments, intreateth of it in his first Bookes de vsupartium. Columbus in the last place, because (sayth he) the wonderfull and miraculous frame thereof might remaine infixed in our memories, but we will discourse of the Muscles thereof in this place, because we will follow the order of dissection.
Seeing therefore that the proper action of the Hand is Apprehention, and Appre∣hention a Motion depending vpon our will, it was also necessary that the hand should haue muscles which are the instruments of voluntary motion whereby it might be moo∣ued altogether and euery finger apart.
The muscles therefore which moue the hand are of two sortes, some haue the guide of the motion of the whole Hand, others moue the Fingers onely. The former are like∣wise of two sortes; for some doe either bend or extend the VVrist, and consequently the Hand with the same motion, others mouing the Radius or VVand do together also turne the Hand downward or vpward.
These Muscles are seated vpon the cubit either on the outside or on the inside. Hither also may we referre that Muscle that moueth the skin which is in the palme of the Hand. These that moue the Fingers doe either bend them or extend them or moue them side∣long, that is, ioyning them together or parting them asunder.
But because the thumbe which is called Pollex, for that it is aequipolent or aequiualent to the whole Hand, hath in his bending and extending something peculiar to himselfe, differing from the same motions in the other foure Fingers, therefore it hath his peculiar Muscles, as also the rest of the Fingers haue theirs, whereof some are seated in the cubit, others in the After-wrist and others in the ball or palme of the Hand.
Againe, because the articulation is diuers in the first ioynts of the fiue Fingers and in the second of the Thumb, from that it is in the second and third ioynts of the foure Fin∣gers and the third of the Thumbe, because the latter are ioyned by ginglymos the vpper bone receiuing into his bosome the protuberation or swelling of the lower, and the lo∣wer bone into his cauity the heads of the vpper: hence it commeth to passe that their mo∣tion is onely simple, absolued by extention and flexion without any inclination to either side: but the first bones of the foure fingers and the first of the thumbe being fastned by a firme articlation to the bones with which they are sustayned, are not onely bent and ex∣tended, but inclined also to the sides as they are led to-ward or fro-ward the thumb.
I could busie my selfe and you too in setting downe each Authors diuision of the mus∣cles of the Hand, for euery one almost differs from another, but because the History that followeth dependeth most what vpon Bauhines relation, therefore we will remit him that is desirous to know each mans minde vnto their proper discourses, & content our selues with Bauhine alone.
In the whole summe therefore the Muscles which mooue the Hand are forty; foure of the wrist, foure of the wand, of the palme of the hand three sometimes foure, and 29. of the fingers.
Some of these Muscles were seated in the cubite because it was very necessary they should be large, and their tendons onely are transmitted vnto the fingers. For if they had beene placed in the Hand they must needs haue increased the bulke thereof to that quan∣tity which would haue been preiudiciall to the vse of so excelent an organ. Notwithstan∣ding some are situated in the Hand.
Of these Muscles there are nine benders, two bend the foure fingers and seauen the Thumbe. The extenders are 20. sixeteene extend the 4. fingers, in which number are those foure called Lumbricales the VVormy muscles, and those eight called Interossei, be∣cause they lurke betweene the bones. The other foure extenders doe serue the thumbe which they doe either simply extend or leade to the fingers or from the fingers: the ten∣dons of which foure muscles as Galen obserued in the 17. chapter of his sixt Booke de vsu portium, are infixed in the ioynt of the bone that is to be moued. But because in dissec∣tion