The _Transversus_ having its beginning in the transverse _Apophyses_ of the _Vertebra"s_ of the Loins, is fasten"d to the internal Rib of the _Os Ilium_, and within the Cartilages of the lower Ribs, and is terminated by a large _Aponeurosis_ in the _Linea Alba_, pa.s.sing over the _Rectus_, and sticking to the _Peritonaeum_.
The Oblique Muscles, and the Transverse, have Holes toward the Groin, to give Pa.s.sage to the Spermatick Vessels of Men, and to a round {36} ligament of the _Matrix_ in Women; so that Ruptures or Burstenness happen through these parts in both s.e.xes, although the Holes of these three Muscles are not situated one over-against another.
The Pyramidal, so named by reason of its Figure, is situated in the lower _Tendon_ of the _Rectus_, its Origine being in the upper and external part of the _Os Pubis_; but it is terminated in the White Line, three Fingers breadth above the _p.u.b.es_, and sometimes even in the Navel itself. These Muscles are not found in all Bodies for there are sometimes two, sometimes only one, and sometimes none.
The use of the Muscles of the lower Belly is to compress all the contain"d parts, in order to a.s.sist them in expelling the Excrements.
_How many Muscles are there in the t.e.s.t.i.c.l.es?_
They have each of them one, call"d _Cremaster_; this Muscle takes its rise from the Ligaments of the _Os Pubis_, and by the dilatation of its Tendon covers the t.e.s.t.i.c.l.e, which it draws upward.
_How many Muscles hath the _p.e.n.i.s_?_
It hath two Pair, _viz._ the _Erectores_ or _Directores_, and the _Dilatantes_: The _Erectores_ arise from the internal part of the _Os Ischion_, under the beginning of the _Corpora Cavernosa_, where they are inserted, and retake their Fibres in their Membranes. The _Dilatantes_ or _Acceleratores_ have their Source in the _Sphincter_ of the _a.n.u.s_ and slipping from thence obliquely under the _Ureter_, are join"d to the Membrane of the Nervous Bodies.
_How many Muscles are there in the _c.l.i.toris_?_ {37}
It hath two Erectors which spring forth from the Protuberance of the _Os Ischion_, and are inserted in the Nervous Bodies of the _c.l.i.toris_. There are also two others suppos"d to be its Elevators, which proceed from the _Sphincter_ of the _a.n.u.s_, and are terminated in the _c.l.i.toris_.
_How many Muscles are there in the _a.n.u.s_?_
There are three, _viz._ the _Sphincter_, and two _Levatores_. The _Sphincter_ is two Fingers broad, to open and close the _r.e.c.t.u.m_. This Muscle being double, is fasten"d in the fore-part to the _p.e.n.i.s_ in Men, and to the Neck of the _Matrix_ in Women, as also behind to the _Coccyx_, and laterally to the Ligaments of the _Os Sacrum_, and the Hips.
The two _Levatores_ arise from the inner and lateral part of the _Os Ischion_, and are fasten"d to the _Sphincter_ of the _a.n.u.s_, to lift it up after the expulsion of the Excrements.
The _Bladder_ hath also a _Sphincter_ Muscle to open and shut its Orifice.
CHAP. X.
_Of the Muscles of the _Omoplatae_, or Shoulder-Blades, Arms, and Hands._
_How many ways doth the _Omoplata_ or Shoulder-Blade move, and what are its Muscles?_
The _Omoplata_ moves upward, downward, forward, and backward, by the means of four proper Muscles, which are the _Trapezius_, the {38} _Rhomboides_, the proper _Levator_, and the lesser _Pectoral_, or _Serratus Minor Anticus_.
The _Trapezius_ or _Cucullaris_ hath its beginning in the back part of the _Occiput_, or hinder part of the Head, in the Spines of the six lower _Vertebra"s_ of the Neck, and of the nine upper of the Back, in pa.s.sing from whence it is implanted in the Spine of the _Omoplata_ or Shoulder-Blade, and the external part of the _Clavicula_, as far as the _Acromion_. This Muscle produceth many Motions by reason of its different Fibres, drawing the Shoulder-Blade obliquely upward, downward, and forward.
The _Rhomboides_ is situated over the _Trapezius_, its rise being in the _Apophyses_ of the three lower _Vertebra"s_ of the Neck, and of the three upper of the Back, but it is afterward join"d to the whole _Basis_ or Root of the _Omoplata_, which it draws backward.
The proper _Levator_ commenceth in the _Transverse Apophyses_ of the four first _Vertebra"s_ of the Neck, by different Progressions, but is afterward re-united, and inserted in the upper Corner of the _Omoplata_, which it draws upward.
The _lesser Pectoral_, or _Serratus Minor Anticus_, is situated under the great _Pectoral_, its rise being by Digitation or Indenting in the second, third, and fourth of the upper Ribs, and its Insertion in the _Apophysis Coracoides_ of the Shoulder-Blade, which it draws forward.
_How many Motions are there in the _Humerus_, or Arm; which be they, and what are its Muscles?_ {39}
The Arm performs all sorts of Motions by the help of nine Muscles: For it is lifted up by the _Deltoides_ and the _Infra-Spinatus_; it is depress"d by the _Largissimus_, and the _Rotundus Major_; it is drawn forward by the _Pectoralis Major_, and the _Coracoideus_; it is drawn backward by the _Infra-Spinatus_, and the _Rotundus Minor_. It is drawn near the Ribs by the _Subscapularis_, and its circular Motion is performed when all these Muscles act together successively.
The _Deltoides_ or _Triangular_ hath its beginning in the whole Spine of the _Omoplata_, the _Acromion_, and half the _Clavicula_, and by its point cleaves with a strong _Tendon_ to the middle of the Arm.
The _Infra-Spinatus_ takes its rise in the Cavity that lies above the Spine of the _Omoplata_, which it fills, pa.s.sing over the _Acromion_, until it is join"d to the Neck of the Shoulder-Bone, which it surrounds with a large _Tendon_.
The _Largissimus_, otherwise call"d _Ani-scalptor_, covers almost the whole Back, proceeding from a large and Nervous Stock, in the third and fourth lower _Vertebra_ of the Back, the five _Vertebra"s_ of the Loins, the Spine of the _Os Sacrum_, the hinder part of the Lip of the Hip-Bone, and the external part of the lower b.a.s.t.a.r.d-Ribs, in pa.s.sing from whence it insinuates it self into the lower Corner of the _Omoplata_, as also into the upper and inner part of the _Humerus_.
The _Rotundus Major_, or _Teres Major_, having its Origin in the external Cavity of the lower Corner of the _Omoplata_, is confounded with the _Largissimus_, and adheres with it by the same {40} _Tendon_ to the upper and inner part of the _Humerus_, a little below the Head.
The greater _Pectoral_ hath its Source in half the _Clavicula_, on the side of the _Sternum_; covers the fore-part of the Breast, and is fasten"d by a short, broad, and nervous _Tendon_, to the top of the Shoulder-Bone, on the inside, between the _Biceps_ and the _Deltoides_.
The _Coracoideus_ or _Coracobrachyaeus_, beginning in the _Apophysis Coracoides_ of the _Omoplata_ or Shoulder-Blade, adheres to the middle of the Arm on the inside, which with the _Pectoral_ it draws forward.
The _Infra-Spinatus_ fills the Cavity which lies below the Spine of the _Omoplata_, its Origine being in the lower Rib of the _Omoplata_, from whence it pa.s.seth between the Spine and the _Rotundus Minor_, to cleave to the Neck of the Shoulder-Bone, which it embraceth, and draws backward.
The _Rotundus Minor_, or _Teres Minor_, proceeds from the lower Rib of the _Omoplata_, and adheres to the Neck of the Shoulder-Bone with the _Infra-Spinatus_ to draw it in like manner backward.
The _Sub-scapularis_ or _Immersus_ is situated entirely under the _Omaplata_, proceeding from the internal Lip of the _Basis_ or Root of the same _Omoplata_, and being terminated in the Neck of the Arm-Bone, which it causeth to lie close to the Ribs.
_How many Motions are there in the_ Cubitus _or Elbow, and what are its Muscles?_
The _Cubitus_ or _Ulna_ is endu"d with two sorts of Motions, _viz._ that of Flection and that of {41} Extension, the former being perform"d by the help of two Muscles, that is to say, the _Biceps_, and the _Brachiaeus Internus_; and the later by eight others, which are the _Longus_, the _Brevis_, the _Brachiaeus Externus_, and the _Anconeus_.
The _Biceps_ is a Muscle with two Heads, one whereof proceeds from the _Apophysis Coracoides_, and the other from the Cartilaginous edge of the _Glenoid_ Cavity of the _Omoplata_ or Shoulder-Blade: These two Heads descend along the fore-part of the Arm, and are united in one and the same Body, from whence springs forth a Ligament, which is inserted in a tuberosity situated in the upper and fore-part of the _Radius_.
The _Brachiaeus Internus_ is a small fleshy Muscle, lying hid under the _Biceps_, which takes its rise in the upper and fore-part of the _Humerus_, and is implanted in the upper and inner-part of the _Radius_, to bend the Elbow with the _Biceps_.
The first of the four Extenders is the _Longus_ having two Sources, _viz._ one situated in the lower Rib of the _Omoplata_, near its Neck, and the other descending to the hinder-part of the Arm, till it is tyed to the _Olecranum_ or _Ancon_, by a strong _Aponeurosis_, which is common thereto, with the _Brevis_, and the _Brachiaeus Externus_.
The _Brevis_ or short Muscle of the Elbow arising from the hinder and upper-part of the _Humerus_, is fasten"d to the _Olecranum_ with the _Longus_.
The _Brachiaeus Externus_ is a fleshy Muscle which proceeds from the hinder part of the {42} _Humerus_, and adheres to the _Olecranum_ with the _Brevis_ and the _Longus_.
The _Anconeus_ or _Cubitalis_ being situated behind the Fold of the _Cubitus_, is the least Muscle of all; it springs from the Extremity of the Arm-Bone, at the end of the _Brevis_ and the _Longus_, and in descending is inserted between the _Radius_ and the _Cubitus_ or _Ulna_, three or four Fingers breadth below the _Olecranum_.
_How many Muscles hath the _Radius_, and which are its Motions?_
The _Radius_ is endu"d with a twofold Motion by the means of four Muscles: Of these the _Rotundus_ and _Quadratus_ cause that of _p.r.o.nation_, as the _Longus_ and the _Brevis_ that of _Supination_.
The _p.r.o.nator Superior Rotundus_, or round Muscle of the _Radius_, commenceth from the inner _Apophysis_ of the Shoulder-Bone, in a very fleshy Stock, and is terminated obliquely by a Membranous _Tendon_ in the middle and exterior part of the _Radius_.
The _p.r.o.nator Inferior Quadratus_, springing forth from the bottom and inside of the _Cubitus_, is fixt in the lower and outward part of the _Radius_ by a Tail as large as its Head. This Muscle lying hid under the others near the Wrist, is that which jointly with the _Rotundus_, turns the Arm with the Palm of the Hand downward, which is the Motion of _p.r.o.nation_.
The _Longus_ is the first of the _Supinators_, whose Origine is three or four Fingers breadth above the external _Apophysis_ of the Arm-Bone; from whence it pa.s.seth along the _Radius_, and cleaves to the inner-part of its lower _Apophysis_. {43}
The _Brevis_, or the second of the _Spinators_ arising from the lower part of the _Inferior Condylus_, and the external of the _Humerus_, is twisted round about the _Radius_, going forward from the hinder-part till it is united to its upper and forepart. This Muscle, with the _Longus_, serves to turn the Arm and the Palm of the Hand upward, and produceth the Motion of _Supination_.
_How many sorts of Motions belong to the Wrist, and what are its Muscles_?