is big at its upper end and grows smaller to its lower end At its upper it has two Processes which are received into the fore and hind Sinus's of the Extremity of the Humerus the foremost Process is small and short the hindmost called Olecranium is bigger and longer it stays the fore Arm when it comes to a straight line with the Arm. Betwixt these Processes it has a Semicircular Sinus which receives the inner Protuberance of the lower end of the Humerus upon which we bend and extend our fore Arm. The inside of this upper end has a small Sinus which receives the Circumference of the round Head of the Radius It s lower Extremity which is round and small is received into a Sinus in the lower end of the Radius and upon this Extremity it has a short and small Process from which the Ligaments which tie it to the Bones of the Wrist arise this Process serves to keep the Bones of the Wrist in their place The Radius is another Bone of the fore Arm Radius which accompanies the Vlna from the Elbow to the Wrist in its upper end it has a small Cavity which receives the outer Protuberance of the Humerus The Circumference of this Cavity rouls into the small Sinus in the upper end of the Vlna Near its lower end which is bigger than its upper it has a little Sinus which receives the end of the Vlna and in its Extremity it has two Sinus's which receive the Bones of the Wrist Altho' the Vlna and the Radius accompany one another yet they touch not but at their Extremities They bend from one another in their middle but they are tied together by a strong and broad membranous Ligament The Vlna is articulated to the Humerus by a Ginglimus which only admits of the motion of Flexion and Extension to the end that when we lift any great weight the Vlna may not turn to a side and so avoid the resistance of the weight But because if the Hand were only confined to this Motion we could have but little use of it therefore the Wrist is joined to the Radius which performs the Motion of Pronation and Supination by which means the hands partake of the Motion of both Bones The Bones of the Carpus The Carpus or Wrist is made up of eight little Bones of a different Figure and bigness they are placed in two ranks four in each rank The first rank is articulated with the Radius The second with the Bones of the Metacarpus The last little Bone of the first rank lies not at the side of the third which answers to the Bone of the Metacarpus of the little Finger as all the rest do by one another but it lies upon it They are strongly tied together by the Ligaments which come from the Radius and by the annulary Ligaments thorow which the Tendons which move the Fingers pass Altho' this Ligament be thought but one yet it gives a particular case to every Tendon which passes thorow it The Bones of the Metacarpus The Metacarpus is made up of four Bones which answer the four Fingers that which sustains the Fore-finger is the biggest and longest they are round and long a little Convex and round towards the back of the Hand and Concave and plain towards the Palm They are hollow in their middle and full of Marrow they touch one another only at their Extremities leaving spaces in their middle in which lie the Musculi Interossei In their upper end there is a Sinus which receives the Bones of the Wrist and their lower Extremity is round and is received into the Sinus of the first Bones of the Fingers The Bones of the Fingers The Bones of the Fingers and Thumb are fifteen in each Hand three to each Finger they are a little convex and round towards the Back of the Hand but hollow and plain towards the Palm except the last where the Nails are The order of their Disposition is called first second and third Phalanx The first is longer than the second and the second than the third The upper Extremity of the first Bone of each Finger has a little Sinus which receives the round head of the Bones of the Metacarpus The upper Extremity of the second and third Bones of each Finger hath two small Sinus's parted by a little Protuberance and the lower Extremity of the first and second Bones of each Finger has two Protuberances divided by a small Sinus The two Protuberances are received into the two Sinus's of the upper Extremity of the second and third Bones and the small Sinus receives the little Protuberance of the same end of these same Bones The first Bone of the Thumb is like to the Bones of the Metacarpus and it is joined to the Wrist and second of the Thumb as they are to the Wrist and first of the Fingers The second Bone of the Thumb is like the first Bones of the Fingers and it is joined to the first and third as they are to the Bones of the Metacarpus and second of the Fingers The Fingers are moved side-ways only upon their first Joint Ossa Sesamoidaea Besides these Bones there are some small ones called Ossa Sesamoidaea because they resemble the Grains of Sesamum they are reckoned about 12 in each Hand they are placed at the Joints of the Fingers under the Tendons of the Flexores Digitorum to which they serve as so many Pulleys SECT XIV Of the Bones of the Thighs Legs and Feet THE Thigh has only one Bone which is the longest of all the Bones of the Body its Fibres are close and hard it has a Cavity in its middle 't is a little convex and round on its foreside but a little hollow with a long and small ridge called Linea Aspera on its backside At its upper end it has three Epiphises which separate easily in Children The first is its Extremity which is a large and round head covered with a Cartilage which is received into the Acetabulum Coxendicis wherein it is tied by two Ligaments The first is pretty large and comes from the edge of the Acetabulum The second is round and short it comes from the bottom of the Acetabulum and is inserted in the middle of the round head the Part immediately below this round head which is small long and a little Oblique is called its Neck It makes an Angle with the Body of the Bone by which means the Thighs are kept at a distance from one another that the Muscles on the inside of the Thighs might lie the more conveniently without rubbing upon one another or hurting of the Privities Besides this obliquity of the Neck of the Bone conduces much to the strength of the Muscles of the Thigh because it removes their Insertions from the Center of Motion Trochanter major The second is called Trochanter major it is a pretty big Protuberance on the External side
the Intestines At this Orifice the Tunicles of the Stomach are much thicker than they are any where else and the inmost has a thick and strong Duplicature which serves as a Valve to the Pylorus when it contracts and shuts Its Coats The Stomach is made of four Membranes or Coats The first and inmost is made of short Fibres which stand perpendicularly upon the Fibres of the next Coat they are to be seen plainly towards the Pylorus This Coat is much larger than the rest being it is full of Plaits and wrinkles and chiefly about the Pylorus These Plaits retard the Chyle that it run not out of the Stomach before it be sufficiently digested In this Coat there are also a great number of small Glands which separate a Liquor which besmears all the Cavity of the Stomach therefore this Coat is called Tunica Glandulosa The Second is much finer and thiner it is altogether nervous it is of an exquisite sense and it 's called Nervosa The Third is Muscular being made of straight and circular Fibres the straight run upon the upper Part of the Stomach between its superior and inferior Orifices and the circular run obliquely from the upper part of the Stomach to the bottom These Fibres by their Contraction and continual Motion help the attrition and digestion of the Aliments The Fourth Tunicle is common it comes from the Peritonaeum The Stomach receives Veins from the Porta Its Vessels viz. the Gastrica Pylorica and Vas breve and branches from the Gastro-epiplois dextra sinistra which are accompanied with branches of the Arteria Coeliaca all which lie immediately under the fourth Coat of the Stomach The Eight pair of Nerves or Par vagum gives two considerable branches to the Stomach which descending by the sides of the Gullet divide each into two branches the External and Internal The two External branches unite in one and the Internal do so likewise both which piercing the Midriff form by a great number of small twigs upon the upper Orifice of the Stomach a Plexus and then the Internal branch spreads its self down to the bottom of the Stomach and the External branch spreads it self upon the inside about the upper Orifice of the Stomach This great number of Nerves which is about the upper Orifice renders it very sensible and from them also proceeds the great Sympathy betwixt the Stomach Head and Heart upon which account Van Helmont thought that the Soul had its seat in the upper Orifice of the Stomach The Plexus Nervosus of the Hypochondria and Mesenterium give several branches to the bottom of the Stomach therefore in Hysterick and Hypochondriack Passions the Stomach is also affected It s use The Use of the Stomach is Digestion which is the Dissolution or Separation of the Minute Parts of the Aliments not only by the Saliva and Succus of the Glands in the bottom of the Stomach but also by the continual motion of its muscular Fibres and when this Aliment is sufficiently dissolved in the Stomach it is by these same Fibres thrown out at the Pylorus into the Intestines SECT VIII Of the Intestines What the Guts are THE Intestines or Guts are a long Canal which being knit all along the Circumference of the Mesenterium by several Circumvolutions reaches from the Pylorus to the Anus They are six times the length of the Body in which they are By which means the Chyle has time enough to be separate from the faces before they are cast out at the Anus Their Coats They are composed of three Coats The inmost is nervous and very sensible it is full of circular wrinkles and Plaits which retard the motion of the Chyle and descent of the Excrements It is covered with a mucous sort of crust which defends it against the Acrimony of the Bile In this crust there are an infinite number of small Glands they are placed as it were by Plotouns in the small Guts but in the great Guts they are fewer and are placed one by one they lie only in that side of the Intestine which is knit to the Mesentery Some say that they have each an excretory Duct which pours â—nto the Cavity of the Intestines a white Liquor which serves to hasten the Separation of the Chyle from the Faeces others think that they separate the mucosity which besmears the inside of the Intestines and a third opinion drawn from their situation and the Liquor which is found in them is that they are only Caruncles placed at the Mouths of the Lacteal Veins The second Coat is made of Spiral and straight Fibres The Spiral Fibres contract the Cavity of the Intestines when they act and the straight Fibres shorten the Intestines when they contract The third and External Coat is common it cometh from the Peritonaeum The Division of the Guts Tho' the Intestines be one continued Pipe yet Anatomists divide it into six Parts three thin and small and three thick and great The three thin and small are the Duodenum Jejunum and Ileum Of the Duodenum The Duodenum is the first Part of the Intestines it 's about twelve fingers breadth long it is continued to the Pylorus from which turning downwards it runs under the Stomach immediately above the Vertebrae towards the left side and ends at the first of the windings under the Colon. At its lower end there are two Canals which open in its Cavity one comes from the Liver and Gall bladder called Ductus communis Cholidochus the other from the Pancreas called Ductus Pancreaticus The first brings the Bile the second the Succus Pancreaticus into this Intestine It differs from the other two in this that its Passage is straiter and its Coats thicker Of the Jejunum The Second is the Jejunum it begins at the first winding of the Guts under the Colon where the Duodenum ended and making several turnings and windings from the right side to the left and from the left again to the right it is continued to the Ileum filling all the upper part of the Umbilical Region being about 12 or 13 hands breadth long It differs from the Ileum only in this that it hath some more Venâ— Lacteae into which the Chyle passing it is found always more empty therefore it 's called Jejunum And the folds or membranous circles of its inner Coat are nearer to one another and in greater number than in the Ileum Of the Ileum The Third and last of the small Guts is the Ileum it is about 21 hands breadth long it begins where the Jejunum ends and making several turnings and windings it fills all the lower part of the Umbilical Region and all the space betwixt the Ilia and is continued transversely not in a streight line to the beginning of the Colon in the right side its Passage is a little narrower than that of the Jejunum and its Coats seem somewhat thinner This Intestine because of its situation
falls easily down into the Scrotum by the Productions of the Peritonaeum In it also happens the Volvulus when one part of this Gut enters the Cavity of another The thick and great Guts are the Caecum Colon and Rectum Of the Caecum The Caecum altho' small yet is taken for the first of the great Guts but the Ancients who made this Division of the Guts called the beginning of the Colon the Caecum and what is now called Caecum they called Appendix Caeci It is four or five fingers breadth long and about the bigness of a Swan's Quill It is called Caecum because it is open only at one end by which it is tied to the beginning of the Colon to which it seems to be an Appendage so that the Excrements go in and come out at the same Orifice It s other end which is shut is not tied to the Mesentery but to the right Kidney by means of the Peritonaeum It s use is yet unknown Some take it for a second Stomach others for a receptacle of the Excrements of the Foetus in which it 's always full till after the Birth Others say it contains a ferment and others the flatuosity of the Intestines and others that it separates a Liquor by some Glands which are in its Cavity which Liquor serves to harden the Excrements as they pass thorow the Colon. Of the Colon. The Colon is the greatest and widest of all the Intestines and about eight or nine hands breadth long It begins where the Ileum ends in the Cavity of the Os Ilium on the right side from whence ascending by the Kidney of the same side it passes under the Concave side of the Liver to which it is sometimes tied as likewise to the Gall Bladder which tinges it yellow in that place then it passes under the bottom of the Stomach to the Spleen in the left side to which it 's also knit from thence it turns down to the left Kidney and then passing in form of an S it ends at the upper part of the Os Sacrum into the Rectum At the beginning of this Gut there is a Valve formed by the Production of the inmost Coat of the Intestines in this place it hinders the Excrements which are once fallen into the Colon to return again into the Ileum In its Cavity there are a great number of Cells or membranous Circles formed by â—ts internal Coat they retard the Pasâ—age of the Excrements that we may â—ot be obliged continually to go to â—tool The fleshy Fibres of its second Coat are greater and stronger than â—hose of the other Intestines because 〈◊〉 greater strength was requisite to cause the Excrements to ascend It has a strong Ligament which runs along its upper side from the Ileum to the Rectum it ties the membranous Cells together and strengthens the Colon against the weight of the Excrements and force of Flatuosities In these things it differs from the other Intestines Of the Rectum The Rectum is the last of the Intestines It is a hands breadth and a half long its Cavity is about three fingers in diameter its Coats are thicker than those of the Colon. It begins at the upper part of the Os Sacrum where the Colon ends and going straight down it is tied to the extremity of the Coccyx by the Peritonaeum behind and to the Neck of the Bladder in Men and in Women to the Neck of the Womb before from thence comes the Sympathy between these Parts There is very much Fat about its external side therefore it is called the Fat Gut Its Extremity forms the Anus into which there are three Muscles inserted The first is the Sphincter Ani Of the Museles of the Rectum this is a fleshy Muscle about four fingers Broad composed of Circular Fibres which embrace the Extremity of the Rectum for three fingers height and which hangs over the Extremity of the Rectuâ— another fingers breadth so that in the Operation for a Fistula in Ano there is always an Inch more of this Muscle cut than there is of the Rectum It is connected forwards to the acceleratores Vrinae in Men and to the Neck of the Womb in Women and backwards to the Os Coccygis It s use is to shut the Passage of the Anus which the weight of the faeces open The other two Muscles are the Livatores Ani they arise from the Internal and Lateral side of tho Os Ischium and are inserted into the Sphincter Ani They draw the Anus upwards A Palsy of the Sphincter causes an involuntary running of the Excrements and a Palsy of the Levatores causes a descent of the Anus Of the Vessels of the Guts The Intestines receive Veins from the Porta which are distributed in many small branches called Meseraicae Another branch creeps along the Colon to the Anus called Haemorrhoidalis it is accompanied by an Artery of the same Name The Hypogastrick Veins and Arteries give them also some branches And the Mesenterica Superior and Inâ—erior accompany the branches of the Veins The Nerves which are distributed in the Intestines come from the Interâ—ostal The Anus receives some also from the Os Sacrum they carry the Animal Spirits necessary for the Peristaltick Motion of the Guts The use of the Guts The Aliment which was dissolved in the Stomach being thrown into the Duodenum is mixt with the Bile and Pancreatick Juice which not only dissolve and attenuate it further but they â—lso precipitate its grosser Parts or Faeces whilst its finer Parts are by the pressure of the Midriff Muscles of the â—ower Belly and contraction of the Muscular Fibres of the Intestines thrust into the Mouth of the lacteal Vessels The Faeces are by the successive motion of the Spiral Fibres and contraction of the streight ones thrust from one Part of the Intestines into another â—ill at last they are thrown out at the Anus This Motion of these Fibres is called the Peristaltick Motion of the Guts SECT IX Of the Mesentery Lacteal Vessels 〈◊〉 receptacle of the Chyle and Ductâ—â— Thoracicus The Description of the Mesentery THE Mesentery is a triple Mâ—â—â—brane placed in the middle of the Abdomen almost of a circular figure with a narrow Production to which the end of the Colon and beginning of the Rectum are tied It is about four fingers breadth and a half in Diament its Circumference being full of Plâ—â—â— and Foldings is about three Ells 〈◊〉 length the Intestines which are tiâ—â—â— about this Circumference are about eight or nine Ells long so that to eveâ— Inch of the Circumference of the Mâ—sentery there are three Inches of the Intestines tied It is strongly tied 〈◊〉 the first and third Vertebre of the Loâ—â— It 's composed of three Membranes the inner Membrane which is thicker thâ—â— the other two and upon which the Glands and Fat lie and the Veins and Arteries run is its own proper Membrane and the
up in the act of Generation Of the Albuginea The Second is that which covers immediately the Testicles It is called Albuginea because of its white colour It is strong and thick very smooth and equal the Coats of the Vasa Praeparantia are united to it Of the Substance of the Testicles The Substance of the Testicles which formerly was thought to be a sort of Marrow is nothing but the folding of several small Vessels which have no conspicuous Cavity disposed in such a manner that if they could be separate from one another without breaking them they might be drawn out to a great length These Foldings are separate from one another by thin Membranes which come from the inner side of the Albuginea At the end of the Testicles Of the Epididymiâ— they send out six or seven small Vessels which piercing the Tunica Albuginea unite into one Canal which by several turnings and windings upon the upper part of the Testicles forms this Body which we call Epididymis They are covered with a thin Production of the Albuginea The same Canal continuing and ascending from the Extremity of the Epididymedes Of the Vasa Deferentia forms the Vasa Deferentia or Jaculatoria one from each Epididymis about the bigness of a Goose-quill with a conspicuous Cavity as they ascend within the Tunica Vaginalis they make several Serpentine turnings and windings then they enter by the holes of the transverse and oblique Muscles into the Abdomen and marching over the Ureters between the backside of the Bladder and the Rectum they grow larger as they approach the Vesiculae seminales which discharge their humour into them where they come close to one another and growing again smaller and smaller they pass thorow the Prostatae and open into the Vrethra a little below the Neck of the Bladder where each Orifice has a spongious border which hinders the involuntary running of the Seed they may sometimes be mistaken by Surgeons for a Carnosity of the Yard The Spermatick Arteries carry the Blood from the Aorta to the Testicles which separate that Part of it which is fit for Seed The Veins carry back to the Cava what Blood remains after the Secretion of the Seed and the Nourishment of the Parts The Seed is further purified in the Epididymides and in coition is carried by the Vasa Deferentia into the Vrethra Of the Vesicuâ—â—e Seminales The Vesiculae Seminales are two in Number one on each side situated betwixt the Bladder and the straight Gut tied to the one and the other by a Membrane of fleshy Fibres which in time of Coition swells and presses the Vesiculae They are covered with a a pretty thin Membrane upon which do creep many branches of Veins Arteries Nerves and Lymphaticks Their External Surface resembles that of the Intestines of a little Bird which in some places of their Circumvolitions are broad in others narrow they are about three fingers breadth long their broadest part is about an inch from which they grow narrower by little and little to their end which is next the Prostatae They have two considerable Cavities divided into membranous Cells which open distinctly by two Orifices which are in their small Extremities into the two Vasa Deferentia into which they discharge a pretty thick and clear humour which embraces the true Seed which comes from the Testicles Of the Prostatae The Prostatae or Corpus Glandulosum is situated at the Neck of the Bladder covered with a Membrane made of muscular Fibres as that of the Vesiculae and for the same use It is about the bigness of a Walnut the Vasa Deferentia pass thorow its Substance which is Vesicular and Glandulous full of an oleaginous and viscous humour which is carried into the beginning of the Vrethra by eight or nine excretory Ducts which open about the Orifices of the Vasa Deferentia the border of their Orifices is also spongious to hinder a continual running of this humour The Prostatae have Veins Arteries Nerves and Lymphaticks They are the Seat of the Gonorrhaea's for it the morbifick Matter fixes in them it enflames corrodes and ulcerates them from whence there is a continual running of purulent Matter Of the Yard The shape figure and dimensions of the Yard are well enough known It is covered with the Skin and Scarf-skin The Skin at the end of the Yard folds in and forms a Hood to the Glans called Praeputium which is fixed to the lower part of the Glans by a little Ligament called Fraenum The Substance of the Yard is composed of two nervous Bodies called Corpora Cavernosa they arise at two different places from the lower part of the Os Pubis a little from their root they come close together being only divided by a Membrane which at its beginning is pretty thick but as it approaches the end of the Yard it grows thinner and thinner and the two nervous Bodies terminate in the Balanus The External Substance of these nervous Bodies is hard firm close and nervous the Internal is membranous loose and spongious full of Veins and Arteries Of the Balanus The Balanus or Glans is only a continuation of the soft and spongious Internal Substance of the two nervous Bodies covered immediately with a thin Membrane which is a Dilatation of the Internal Membrane of the Vrethra About the Crown of the Glans where the Praeputium is contiguous to it there are several small Glands which lie under its thin Membrane they separate a whitish humour for the moistening the Balanus In a Phimosis this humour not only hardens but may grow acid and ulcerate the Glans Of the Urethra The Vrethra is a Conduit which reaches from the neck of the Bladder to the end of the Yard in the middle and lower part of the two nervous Bodies It s Substance is externally hard and internally spongious like that of the nervous Bodies except a little at the neck of the Bladder which is membranous With in its Cavity is covered with a thin and exquisite Membrane in which some have observed several Glands which separate a Liquor for preserving it against the Acrimony of the Urine Of the Vessels of the Yard The Yard has a small Ligament which arises from its back a little distance from its root which ties it to the upper part of the Os Pubis that it may not hang too low It receives two branches of Veins and Arteries from the Hypogastrick Vessels besides others from the Pudenda they are distributed thorow all the body of the Yard particularly thorow the spongious Part of the Corpora Cavernosa and Vrethra The two Veins unite near its roots and form one trunk which runs along the upper side of the Yard It has two Nerves from the Os Sacrum and several Lymphaticks which empty themselves into the Inguinal Glands Of its Muscles and Erection The Yard has two pair of Muscles The First
nothing but a bundle of small Husks which answer to so many Papillae of the Skin From whence we may conclude that the Nails are nothing but the covers or sheaths of the Papillae Pyramidales of the Skin on the Extremities of Fingers and Toes which dry harden and lie close upon one another their use is to defend the ends of the Fingers when we handle any hard or rugged Body The Bones of a Skeleton are The Os Frontis 1 Occipitis 1 Ossa Parietalia 2 Temporum 2 Ossicula Auditus 8 Os Ethmoides 1 Sphaenoides 1 Mali 2 Maxillare 2 Vnguis 2 Nasi 2 Palati 2 Vomer 1 Maxilla Inferior 1 Dentes Incisivi 8 Canini 4 Molares 20 Os Hyoides 1 Â 61 Vertebrae Cervicis 7 Dorsi 12 Lumborum 5 Ossis Sacri 6 Os Coccygis 3 Scapulae 2 Claviculae 2 Costae 24 Sternum 1 Ossa Innominata 2 Â 64 The Humerus 2 Vlna 2 Radius 2 Ossa Carpi 16 Metacarpi 8 Digitorum 30 Â 60 The Os Femuris 2 Rotulae 2 Tibia 2 Fibula 2 Ossa Tarsi 14 Metatarsi 10 Digitorum 28 Â 60 In all 245 Besides the Ossa Sesamoidaea which are sometimes found to the Number of 48. CHAP. VI. Of the Muscles which are not yet described SECT I. Of the Muscles of the Face THE Eye-brows have each a Muscle called Corrugator It arises from the great Canthus of the Orbit and terminates in the Skin about the middle of the Eye-brows Some reckon this Pair only a Prolongation of the Frontales their Name declares their Use The Nose has three Muscles The first arises from the upper end of the two Bones of the Nose and are inserted into the upper Part of the Alae They pull the Nose upwards The second Pair arise from the Os Maxillare and are inserted into the sides of the Alae They dilate the Nostrils The third Pair arise from the same Bone above the Dentes Incisorii and are inserted into the Extremities of the Alae which they pull downwards The Muscles of the Lips are four Proper Pair The Incisivus or Elevator Labii Superioris it arises from the upper Part of the fourth Bone of the upper Jaw and descending obliquely is inserted into the upper Lip above the Dentes Incisorii It s Antagonist is the Triangularis or Depressor Labii Superioris it ariseth from the lower edge of the lower Jaw between the Massater and the Quadratus and ascendeth by the Angle of the Mouth to the upper Lip The Caninus or Elevator Labii Inferioris it ariseth from the fourth Bone of the upper Jaw below the Incisivâ—s it descends and passes under the Intertion of the Zygomaticus and is inserted into the under Lip It s Antagonist is the Quadratus or Depressor Labii Inferioris this is some thin fleshy Fibres which lie immediate under the Skin upon the Chin they arise from the edge of the forepart of the under Jaw and are inserted into the upper Lip There are three Muscles common to both the Lips The first and the second are Zygomatici one on each side they come from the Os Zygoma and going obliquely they are inserted near the Angles of the Lips When one of these Muscles acteth it draws both Lips obliquely to a side they receive often some Fibres from the Caninus The third is the Orbicularis or Sphincter Labiorum it surrounds the Lips with Orbicular Fibres when it acteth it draws the Lips together There is one Muscle on each side common to the Lips and Cheeks which is the Buccinator it lies under the other Muscles it makes the inner Substance of the Cheeks its Fibres run from the Processus Coronae of the lower Jaw to the Angle of the Mouth And they adhere to the upper part of the Gums of both Jaws Thorow its middle pass the upper Ductus Salivales by this Muscle we contract the Cavity of our Mouth and thrust the Meat between our Teeth The Muscles of the lower Jaw are twelve Pair six on each side The first is the Temporalis or Crotaphites it arises by a Semicircular fleshy beginning from a Part of the Os Frontis from the lower Part of the Parietalis and upper Part of the Temporalis From thence they go under the Zygoma and gathering together as to their Centre they are inserted by a short but strong Tendon into the Processus Coronae of the lower Jaw The second is the Massater it is a thick and short Musele it arises from the Zygoma and from the first Bone of the upper Jaw and is inserted into the lower edge of the lower Jaw from its External Angle to its middle It s Fibres run in three Directions those which come from the Zygoma run obliquely to the middle of the Jaw and those from the first Bone of the upper Jaw cross the former and run to the Angle of the lower Jaw and the Fibres which are in its middle run in a perpendicular from their Origin to their Insertion These two Muscles pull the Jaw upwards The third is the Pterigoidaeus Internus it arises from the Internal Part of the Processus Pterigoidaeus and descends to be inserted into the Inferior Part of the Internal side of the lower Jaw near its Angle When this Muscle acteth it draweth the Jaw to a side The fourth is the Pterigoidaeus Externus it ariseth from the External Part of the same Process and goes backwards to be inserted between the Processus Condiloides and the Coronae on the inside of the lower Jaw This Muscle pulleth the lower Jaw forwards The fifth is the Quadratus this is a broad membranous Muscle which lies immediately under the Skin it ariseth from the upper Part of the Sternum from the Claviculae and from the Acromium it covereth all the Neck and adheres firmly to the lower edge of the lower Jaw and being produced it covers also the lower Part of the Cheeks When this Muscle acteth it pulleth the Cheeks and Jaw downwards The sixth is the Digastricus it ariseth fleshy from the upper Part of the Processus Mastoidaeus and descending it contracts into a round Tendon which passes thorow the Stylohyoidaeus then it grows fleshy again and ascends to the middle of the edge of the lower Jaw where it is inserted When this Muscle acteth it pulleth the lower Jaw down SECT II. Of the Muscles of the Head THE Head is lifted up or pulled backwards by four pair of Muscles The first is the Splenius which ariseth from the four upper Spines of the Vertebrae of the Back and from the four lower of the Neck and ascending obliquely it adheres to the upper transverse Processes of the Vertebrae of the Neck and is inserted into the upper Part of the Occiput The second is the Complexus it ariseth from the transverse Processes of the Vertebrae of the Neck and ascending obliquely it adheres to the Spines of the same Vertebrae and is inserted into the Occiput When one of these Muscles acteth it moves the Head backwards to one side The