pressed for the distribution of the Chyle but it diminishes the Cavity of the Breast when it resumes its natural Situation and presses the Lungs for the Expulsion of the Air in Expiration SECT III. Of the Pleura Mediastinum and Thymus Of the Pleura THE Pleura is a double Membrane which covers all the Cavity of the Thorax it arises from the Vertebrae of the Back ascends on each side upon the Ribs to the middle of the Sternum It is fixed to the Periostium of the Ribs to the internal intercostal Muscles and it covers the Midriff It s side towards the Cavity is smooth and equal but that which is fixed to the Ribs is rough The Vessels which run betwixt its Duplicature are Veins from Vena Azygos and upper intercostal Vein Arteries from the Inferior and Superior intercostal Arteries and Nerves from the twelfth Pair of the Back from the intercostal Pair and from the eighth Pair Of the Mediastinum The Mediastinum is a double Membrane formed by the continuation of the Pleura it comes from the Sternum and goes straight down thorow the middle of the Thorax to the Vertebrae dividing the Cavity in two It contains in its doubling the Heart in its Pericardium the Vena Cava the Oesophagus and the Stomachick Nerves The Membranes of the Mediastinum are finer and thinner than the Pleura and they have a little Fat The Mediastinum receives branches of Veins and Arteries from the Mammillary and Diaphragmatick and one Proper called Mediastina its Nerves come from the Stomachick it has also some Lymphaticks which open in the Thoracick Duct The Mediastinum divides the Thorax in two Parts to the end that one Lobe of the Lungs may officiate if the other be hindered by a Wound on the other side of the Thorax it fixes the Heart in its Pericardium and preserves them from external Injuries Sometimes there is a matter contained betwixt its Membranes immediately under the Sternum which may occasion the Trepaning of this place Of the Thymus The Thymus passes for a Conglomerate Gland a little softer than the Pancreas situated in the upper Part of the Thorax under the Claviculae where the Cava and Aorta divide into the Subclavian branches This Gland is big in Infants but as they grow in Age it grows less It receives Veins and Arteries from the Jugulars Nerves from the Par Vagum and Lymphatick Vessels which discharge themselves in the Subclavian Vein The use that is commonly given to the Thymus is to be a little Cushion to support the Thoracick Duct and to strengthen the Cava and Aorta at their Divisions in the Subclavian Vessels to defend them against the hardness of the Vertebrae But 't is probable that its principal use is to filtrate or separate some Liquor which is not yet known SECT IV. Of the Pericardium Heart and its Parts Of the Pericardium THE Pericardium is a thick Membrane of a Conick Figure it resâ—mbles a Purse and contains the Heart in its Cavity It s Basis is pierced in five places for the Passage of the Vessels which enter and come out of the heart it is fixed to the Mediastinum and to the Midriff It receives its Vessels from the Axillaries and Phrenicae Nerves from the recurrent and Diaphragmatick It has Lymphaticks which discharge themselves in the Thoracick Duck. It defends the Heart from external Injuries Of the Water contained in the Pericardium In the bottom of the Pericardium there is a clear and sweet tasted Water but in some tinctured a little with Blood It is found in abundance in the Pericardium of Women and Old Men but there is little of it in those that are Hectick and Pleuritick When it is in too great quantity it causes a Palpitation of the Heart and sometimes Death Authors do not agree about the rise of this Water Some say that it comes from the Extremities of the Arteries others that it comes thorow the Substance of the Heart but it 's more probable that it is filtrated thorow the Glands which are at the basis of the heart and that it may not abound too much nor putrify by standing too long it is taken up by some small Glands which are in the Membrane of the Pericardium and from them carried by the Lymphaticks into the Thoracick Duct Of the Situation Figure and Connexion of the Heart The Heart is situated in the middle of the Thorax between the two Lobes of the Lungs it is of a Conick Figure It s basis is the upper end and its Apex or Point is the lower end which is turned a little to the left side therefore its motion is best felt there It is tied to the Mediastinum to the Pericardium and sustained by the great Vessels which bring and carry back the Blood It is covered by a Membrane which is the proper Membrane of the Muscles its basis is always surrounded with Fat in which there are some small Glands Of its Vessels It has two Veins which come from the Cava immediately before it opens in the Heart and they are accompanied with two Arteries from the Aorta which run thorow all the Substance of the Heart they are called the Coronal Vessels The Veins on the right side communicate at their Extremity with the Veins of the left In like manner do the Arteries of each side communicate with one another and it is the same almost in all the Parts of the Body The Heart receives a multitude of small Nerves from the eighth Pair particularly they creep in great numbers about the Aorta and on the left Ventricle It has also some Lymphaticks which discharge themselves in the Thoracick Duct At the basis of the Heart there are two Auriculae or little Ears Of the Auriculae one on the right the other on the left side In the right Ear opens the Vena Cava in the left the Vena Pulmonaria The first discharges the Blood that it receives from the Cava into the right Ventricle and the second thrusts the Blood that comes from the Vena Pulmonaria into the left Ventricle Their Figure is like the triangle Ambligonium the left is less but thicker than the right Their Substance is composed of two Orders of muscular Fibres which terminate in the tendon in the basis of the Heart and at the right Ear there is a circle like to a tendon where the Cava ends Their external Surface is smooth their internal is unequal full of small fleshy Pillars which send out small Fibres that cross and go thwart one another and betwixt these Pillars there are as many furrows which are more in the left than in the right Ear they receive Nerves from the branches of the eighth Pair They have the same motions of Systole and Diastole as the Heart which we shall explain afterwards Their Vse Their Use is to receive the Blood which is brought by the Veins and by them to be thrust
into the Ventricles of the Heart Of the Ventricles of the Heart In the Heart there are two Cavities or Ventricles which answer to the two Ears one on each side the sides of these Cavities are very unequal full of Fibres and little fleshy Productions long and round of a different Figure and bigness called Columnae or Pillars Betwixt these Fibres there are several furrows in the sides of the Ventricles especially in the left Ventricle they are deeper and larger they contribute much to the close contraction of the Ventricles And because the side of the right Ventricle is much thinner than the left therefore there are often two or three fleshy Fibres which come from the middle Partition to its opposite side to hinder it from dilating too much The right Ventricle seemeth wider than the left which is longer and narrower than the right and its sides stronger and thicker The two Ventricles are separated by the Septum Medium which is properly the inside of the left Ventricle being its Fibres are continued with the Fibres of the opposite side of the same Ventricle The Vessels which enter and come out of the Heart are the Vena Cava the Arteria and Vena Pulmonaria and the Aorta or Arteria Magna Of the right Ventricle and of its Valves The right Ventricle receives the Blood from the Vena Cava thorow the right Ear and at the mouth of the Ventricle there are placed three Valves made of a thin Membrane they are of a triangular Figure and are called Tricuspides their bases are fixed to the mouth of the Ventricle and their Points tied by small Fibres to the fleshy Productions so that when the Heart contracts its Point approaches its basis the fleshy Productions move upwards therefore the Fibres of these Valves are relaxed and the Valves lifted up by the Blood which gets underneath them because the furrows and fleshy Productions keeping the Valves at a little distance from the sides of the Ventricle give way to the Blood to pass under them and so to thrust up the Valves which shut so closely the entry into the Ventricle that the Blood cannot return the way it came in But when the Ventricle is dilated the Fibres are pulled down and the Passage made open for the Blood to enter Of the Valves of the Arteria Pulmonaria When the Heart contracts the Valves being lifted up the Blood in the right Ventricle finds an open Passage into the Arteria Pulmonaria which rises immediately out of the right Ventricle its Mouth is less than the Cava it has three Valves called Segmoidales or Semi-lunares because they resemble a Half-Moon or Segment of a circle their Substance is membranous When they separate they give passage to the Blood from the Ventricle into the Artery but they shut the Passage and are thrust together by the Blood if it endeavours to return Of the Valves of the left Ventricle The Vena Pulmonaria discharges it self thorow the left Ear into the Ventricle of the same side At the Orifice of this Ventricle there are two Valves called Mitrales because when they are joined together they resemble a Mitre they are broader than the other Valves they are situated and have the same use as the Tricuspides in the right Ventricle Of the Valves of the Aorta The Aorta or great Artery rises immediately out of the left Ventricle it has three Valves which have the same Use and Figure as the Semi-lunares in the Arteria Pulmonaria Of the Substance of the Heart and of the order of its Fibres The Heart is a compound Muscle its Substance is made of Fibres of the same Nature as those of other Muscles there are several Orders of them which have different Directions and all their Tendons are in the basis of the Heart The First or External Order is of Fibres which surround the whole Heart they go in an Oblique or Spiral Line from the left to the right except on the Surface of the right side some of its finest Fibres go in a straight Line from the basis to the Point The Second or next order surrounds also the whole heart they have a contrary Direction which is from the right to the left in an Oblique or Spiral Line The next Orders are only proper to the left Ventricle The first which is on the external side of the Ventricle goes in an Oblique Line from the left to the right The second Order is on the inside or that which makes the Septum Medium or Partition Wall of the Ventricles they go in an Oblique Line from the right to the left and they are continued with the foregoing Fibres at the Point of the Heart All these Orders of Fibres come together as to one common Centre at the Point of the Heart But Obs That all the Fibres of the same Order do not always go from the basis to the Point for some after they have gone about half way obliquely from the one side turn up obliquely and are inserted in the basis on the other side Neither do all the Fibres in the same order keep together for some intermix with the Fibres of the next Order so in separating these Orders many Fibres are broken Some of the Fibres in the internal Orders proper to the left Ventricle terminate in the fleshy Productions of the same Ventricle The Bone which is found in the basis of the Hearts of several Beasts is nothing but the tendons of the Fibres of the Heart ossifyed it is sometimes found in Men. Of the Systole and Diastole of the Heart This Muscle has two Motions which they call Systole and Diastole The Systole is when the Fibres of the Heart contract its Point approaches its basis the Heart becomes short its sides swell and its Cavities are strongly pressed on all sides The Diastole is when this Muscle ceaseth to act its Fibres are lengthened its Point retires from its basis its sides fall and its Cavities become large and wide Of the Circulation of the Blood thorow the Heart Having described the Heart and its Parts let us now consider the Circulation of the Blood which is performed by means of this Muscle the Vena Cava Ascendens and Descendens unite in one and open into the right Ear where they unite there is a little Protuberance made by their Coats on the inside of the Canal like an Isthmus which directs the Blood both of the one and the other into the Ear and so hinders them from rushing upon one another The right Ear in its Diastole receives the Blood from the Vena Cava which by its Systole is thrust into the right Ventricle for the tendinous Circle which is at the Mouth of the Cava contracts and hinders the Blood to return into it which at the same time is in its Diastole in the Systole of the right Ventricle the Blood is thrust into the Arteria Pulmonaria for it cannot return into the Ear
of it comes out at the hole in the foreside of the same Bone under the Orbit and is distributed in the Cheeks and Nose Another passes under the Processus Zygomaticus and is distributed in the temporal Muscle and the third is distributed in the Palate and Muscles of the Pharynx The third branch of the fifth Pair passes thorow another hole of the Os Sphaenoides and then it divides into two branches the first of which is again divided into four branches of which the first passes between the Condile and the Corone of the lower Jaw to the Massater The second is distributed in the Crotaphites The third passes under the Processus Zygomaticus to the Buccinator Glands of the Cheeks and upper Lip And the fourth passes from behind the Condile of the lower Jaw where it joins the Pars Dura over the Jaw and is distributed in the Face The second branch is divided into three others The first passes between the Pterigoidaeus Externus and the Internus and towards the Angle of the lower Jaw it sends out a branch which makes the Chorda Tympani which goes also to the Muscles of the Malleolus and then it joins the Portio Dura before it comes out of the Cranium the rest is spread on the Chin. The second goes along the sides of the Tongue sends out several branches which join the ninth Pair It gives also some twigs to the Glandulae Sublinguales to the Muscles of the Tongue and Os Hyoides The third goes to the teeth of the lower Jaw by the holes in its inside The sixth Pair The sixth Pair of Nerves rise from the sides of the Processus Annularis This is a small Nerve which passes straight thorow the Foramen Lacerum and is wholly spent on the Musculus Abducens But a little before it enters the Orbit it casts back a branch which alone makes the root of the Intercostal Nerve It passes out of the Skull by the same passage the Carotidale Artery enters As soon as it is come out of the Skull it with a branch of the tenth Pair and of the first and second of the Vertebrae of the Neck forms a large Plexus called Cervicalis Below this it receives a branch made of a twig of the tenth Pair and of the first of the Neck As it descends above the Musculus Scalenus and below the eighth Pair it receives a branch from each of the Vertebral Nerves When it comes to the Clavicula it divides into two branches of which one passes above the Axillary Artery and the other under it and then they immediately join again they with a branch of the first Pair of the Back form a pretty large Plexus at this place and sometimes before for it observes no regularity it casts out a branch which with a branch of the eighth Pair forms the Plexus Cardiacus then it goes down the Cavity of the Thorax under the Pleura near the Vertebrae and as it passes by it receives a branch from every Pair of the Back by which it grows bigger and bigger As it goes out of the Thorax it divides into several branches of which the three Superior in the right side form the Plexus Hepaticus and in the left the Plexus Splenicus These Plexus's furnish Nerves to the Kidneys to the Pancreas to the Caul to the lower Part of the Stomach to the Spleen to the Liver to the Mesentery to the Intestines and their branches form a large Net upon the Mesenterick Arteries called Plexus Mesentericus The Inferior branches as they go down upon the Vertebrae of the Loins receive a branch from the first of the Loins and they send out some branches which join those of the Superior branches which go to the Guts and which form the Net upon the Mesenterick Arteries Then they go down into the Bason and form a large Plexus above the streight Gut to which it gives Nerves as also to the Bladder Vesiculae Seminales Prostratae in Men and to the Womband Vagina in Women Nervus Auditorius The seventh Pair is the Nervus Auditorius it arises from the hind part of the Processus Annularis it enters the hole in the inner Process of the Os. Petrosum it divides into two branches that which is soft is called Portio Mollis and it is distributed in the Labyrinth Cochlea and Membranes which cover the Cavities of the Ear. That which is hard is called Portio Dura it goes out of the Ear by that hole which is between the Processus Mastoides and Styloides it divides into two branches of which one goes to the Muscles of the Tongue or Os Hyoides and it gives a small branch to the eighth Pair The other is distributed in the External Ear Nose Lips and Cheeks Par Vagum The eighth Pair is the Par Vagum it rises from the sides of the Medulla Oblongata behind the Processus Annularis by several Threads which join together and go out by the same hole that the Sinus Laterales discharge themselves into the Jugulares It is joined by a branch of the Nervus Spinalis or Accessorius Willisii and by a small branch of the Portio Dura immediately after it comes out of the Skull it gives a small branch to the Larynx as it goes down the Neck above the Intercostal Nerve by the side of the Internal Carotide At the Axillary Artery it casts back the recurrent Nerves of which the right embraces the Axillary Artery and the left the Aorta These two branches ascend on each side of the Trachea Arteria to the Larynx where they are spent on the Muscles of the Larynx and Membranes of the Trachea Then the eighth Pair after it has entered the Cavity of the Thorax sends out two branches which with the branches of the two Intercostals form a little above the Heart between the Aorta and the Trachea the Plexus Câ—â—dincus which gives a great number of small branches to the Pericardium and Heart particularly very many creep along the Aorta to the left Ventricle The eighth Pair gives also several branches to the Lungs which accompanying the Bronchiae then it descends upon the Oesophagus and is spread upon the Stomach and some twigs go to the Concave side of the Liver as has been said already With this Nerve it is usual to describe another which passes out of the Skull at the same hole with it It is called Nervus accessorius Willisii it arises from the Medulla Spinalis about the beginning of the sixth Pair of the Neck as it ascends to the Head it receives on each side a twig from the first five Pair of Nerves of the Neck as they rise from the Medulla Spinalis then it enters the Skull and passes out of it again with the eighth Pair and is wholly spent upon the Musculus Trapezius The ninth Pair The ninth Pair rises from the Processus Olivares of the Medulla Oblongata it passes out of the Skull by its own proper hole in the Os
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
because of the Valvulae Tricuspides which communicates with the Vena Pulmonaria which carries back the Blood into the left Ear which in its Systole thrusts the Blood into the left Ventricle which is then in its Diastole In the Systole of this Ventricle the Blood is thrust into the Aorta for it cannot return into the Ear because of the Valunlae Mitrales which carries it thorow all the Body Now the Aorta when it comes out of the Heart ascends a little upwards and then turns downwards to form the descending Trunk because the Blood might offend the Brain if it ran with that impetuosity with which it 's thrown out of the Heart and from the upper side of this turning the Cervical and Axillary Vessels do arise by this artifice the Blood collides against the sides of the Aorta its force is broken part of it is taken in by the Mouths of the ascending branches but it s greatest part is directed downwards Of the Circulation of the Blood in the Foetus Let us now consider which way the Blood circulates in the Foetus for this you must observe that in the right Ear on the lower side of the Protuberance of the Cava just opposite to the Mouth of the Cava Descendens there is a hole called the Foramen Ovale which opens into the Vena Pulmonaria this hole has a Valve which suffers the Blood to enter the Vein but hinders it to come back again There is likewise a Passage or Canal called Ductus Bottali which comes from the Trunk of the Arteria Pulmonaria and goes to the Trunk of the Aorta Now the Blood which comes from the Placenta by the Umbilical Vein into the Porta is sent into the Cava by a Canal which goes straight from the Trunk of the Porta to the Trunk of the Cava in the Liver This ascends the Vena Cava and is directly thrown thorow the Foramen Ovale into the Vena Pulmonaria which carries it into the left Ventricle which throws it into the Aorta to be distributed thorow all the Body But the Blood which comes down the Vena Cava ascendens is diverted by the Isthmus of the Cava from the Foramen Ovale and falls into the right Ventricle which thrusts it into the Arteria Pulmonaria from whence it 's immediately carried by the Ductus Bottali into the Aorta to be mixt with the rest of the Blood By this you see that the Blood which comes from the Vena Cava descendens passes only thorow the left Ventricle whilst the Blood which comes from the Cava ascendens passes only thorow the right Ventricle Thus having shewed what way and by what means the Blood circulates thorow the Heart let us now reflect a little upon the quickness of its motion Each Ventricle will at least contain an Ounce of Blood and therefore we may safely suppose that the Heart throws into the Aorta an Ounce of Blood every time it contracts The Heart contracts 4000 times in one Hour or sometimes more and sometimes less according to the different Temperaments Sexes and Ages from which it follows that there passes thorow the Heart every hour 4000 Ounces or 350 Pound of Blood Now the whole mass of Blood is but about 25 Pound so that a quantity of Blood equal to the whole mass of Blood passes thorow the Heart 14 times in one hour which is about once every 4 minutes I say a quantity which is equal to the whole mass of Blood and not the whole mass it self for it is not to be supposed that the Blood which goes to the Extremities can return to the Heart as soon as the Blood which goes only to the Kidneys or Liver The Velocity and quantity of Blood together with the time it takes to run in different Blood Vessels differ according to the different lengths and orifices of the Vessels according to the greater and lesser Compression the Vessels receive in the different Parts thorow which they run according to different quantity of Secretions from the Vessels in the several Parts of the Body according as the Vessels have more or less turnings and windings and according as they divide into more of fewer branches These things determinate the Velocity Time and Quantity of Blood in the several Vessels of the Body In the Blood there is much volatile Salt and Spirits some Phlegm and Sulphur a little Earth but little or no fixt Salt Alcali's dissolve it and Acids coagulate it SECT V. Of the Lungs Of the Figure of the Lungs THE Lungs are in the middle of the Cavity of the Thorax they are divided into two Lobes by the Mediastinum and the left is ordinarily subdivided into two more The Figure of both Lobes together resemble a Cows foot being a little concave betwixt the two Lobes where they embrace the Heart and behind where they lie upon the Vertebrae but before where they touch the Sternum and Ribs they are Convex The colour of the Lungs in a Foetus is of a pale red but after that the Air has once entered them Of their Colour and Connexion they lose their red and remain always pale yet in Adults they are variegated with the one and the other They are tied to the Sternum by the Mediastinum before to the Vertebrae by the Pleura behind where it rises from the Vertebrae to the Heart by the Vena and Arteria Pulmonaria and sometimes to the Pleura where it covers the Ribs particularly in the left side and especially after a Pleurisie Of the Membranes of the Lungs The Lobes of the Lungs are covered with a double Membrane the External is smooth fine but close The Internal is rough and unequal formed by the Extremities of the Vessels and Membrance which tie the Vesicles together It resembles the side of a Honey-Comb Of the Structure of the Lungs Each Lobe is subdivided into an infinite number of little Lobes disposed like so many Grapes upon the Sides and Extremities of the branches of the Bronchiae covered each with their proper Membrane and tied together by a number of Membranes which fill up the Spaces that these Lobes leave between one another Each little Lobe contains an infinite number of small and little Orbicular Vesicles which leave small Interstices between them which are full of small Membranes like those which tie the Lobes together Each Vesicle receives a twig from the branch of the Brochiae that enters the Lobe in which they are contained This twig opens in their Cavity which is divided into little Cells which communicate with one another and a twig from the Vein Nerve and Artery which are spread upon the Membranes of the Vesicle each Vesicle communicates with one another Of the Vessels of the Lungs Now the Vessels which enter the Lungs are the Trachea or Aspera Arteria which comes from the Larynx the Arteria Pulmonaria which comes from the right Ventricle and Vena Pulmonaria which comes from the left Ear
of the Heart each of these divides into two branches for the two great Lobes of the Lungs which being accompanied with the branches from the eighth Pair of Nerves they divide into as many branches as there are little Lobes in the Lungs Where-ever there is a branch of the Trachea there there is a branch of the Nerve Vein and Artery and the Trachea is always in the middle The branches of the Trachea Arteria which are ordinarily called Bronchiae open in the Cavity of the Vesicles and the Nerves Veins and Arteries form Plexus's upon the Membranes of the Vesicles the Arteries open into the Veins by an Anastomosis Besides these the Lungs have Lymphaticks which discharge themselves into the Thoracick Duct accompanying the Vein and they are chiefly to be seen in the External Part of the Lungs There is also a Vein which comes from the Cava that Sommichellius calls Pneumonica and an Artery that M. Ruysh calls Arteria Bronchialis which comes from the Aorta The Artery brings the Blood for the Nourishment of the Substance of the Lungs and the Vein carries back what is superfluous Of the Trachea Arteria This is the passage of the Vessels thorow the Lungs but because the Trachea Arteria has a particular Structure it demands a particular Examination It is a Canal situated in the forepart of the Neck before the Oesophagus it descends from the Larynx to the fourth Vertebrae of the Back where it divides and enters the Lungs and its branches are afterwards called Bronchiae Of its Cartilages This Canal is made of Annular Cartilages which are at small and equal distances from one another These Cartilages the nearer they are to the Larynx the bigger they are and the further they are from it the smaller they are and those of the Bronchiae are so close to one another that in expiration the second enters within the first and the third within the second and so the following always enters the preceeding Betwixt the Larynx and the Lungs these Cartilages make not compleat rings but their hind part which is contiguous to the Oesophagus is membranous that they may the better contract and dilate and give way to the Aliments as they go down the Oesophagus but the Cartilages in the Bronchiae are compleatly Annular only the Extremities of the Bronchiae a little before they open into the Vesicles have no Cartilages but instead of them they have small circular Ligaments which contract and dilate for the reception and expulsion of the Air. Of its Membranes These Cartilages are tied together by two Membranes the one external and the other internal The external is composed of circular Fibres it covers the whole Trachea externally The internal is of an exquisite sense it covers the Cartilages internally It is composed of three distinct Membranes The First is woven of two Orders of Fibres Those of the first Order are Longitudinal for the shortening the Trachea they make the Cartilages approach and enter one another The other Order is of circular Fibres for the contracting the Cartilages When these two Orders of Fibres act they help with the external Membrane in Expiration in Coughing and in the Excretion of any tickling humour The second Membrane is altogether glandulous and the Excretory Vessels of these Glands open in the Cavity of the Trachea they separate a Liquor for the moistening the Cavity and for defending it from the Acrimony of the Air. The third and last is a Net of Veins Nerves and Arteries The Veins come from the Vena Cava the Nerves from the Recurrent and the Arteries from the Carotides Of the use of the Lungs Having thus considered the Structure of the Lungs 't is evident that the Air enters by the Trachea into the Vesicles and so swells and dilates the Substance of the Lungs in Inspiration but in Expiration these Vesicles contract and thrust out the Air which carries a great deal of excrementitious Vapours from the Blood along with it by the Elasticity of their Fibres by the help of the Nerves and by the pressure of the surrounding Bodies employed in respiration It is also evident that the Blood is carried from the Heart by the Arteria Pulmonaria thorow all the Substance of the Lungs and that the same Blood is taken up by the Vena Pulmonaria and carried back again to the Heart And we are sure that whilst the Blood passes thorow the Lungs that it receives some alteration for the Blood in the Arteria Pulmonaria is of a dark colour as venal Blood but that which is in the Vein is of a florid red as Arterial Blood yet how this Alteration is made is not determined by Anatomists Some considering that the Surface of venal Blood drawn in a Pellet and exposed to the Air turns to the colour of Arterial Blood do think that the nitrous Particles of the Air which we breath passes thorow the Tunicles of the Vessels and mixes with the Blood and causes this Alteration which they say is necessary for the recruiting of the Animal Spirits and for the entertaining the natural heat of the Blood by fermenting with the Sulphureous Parts of the Aliments Others explain this Alteration only by the beating and agitation of the Air upon the bloody Vessels of the Lungs which indeed is sufficient to cause this Alteration and the necessity of this beating appears by an Experiment which is this take a little new drawn Blood look to it immediately thorow a Microscope you shall see a number of small red globules swimming in a thin and clear Liquor and the longer you look the more of these Globules join in one and the bigger they grow till at last they all come into one and the Liquor is separated by its self and then the Blood is coagulated Thus the red Globules of the Blood in the Veins as they return from the Extremities grow bigger and bigger for the want of being agitated And if they were not separated and broken into many smaller Particles they would soon cause a stagnation in the Capillary Vessels So the beating of the Air in Inspiration and Expiration is necessary for the attenuating subtilizing and intimately mixing the Chyle Lympha and other Parts of the Blood SECT VI. Of the Larynx It s Situation THE upper Part of the Trachea Arteria is called the Larynx It is almost of a circular Figure lying below the root of the Tongue before the Pharynx It is composed of five Cartilages which sometimes in old Men become as hard as Bones Of the Cartilago Scutiformis The first is the 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 or Scutiformis because of its Figure It makes that Protuberance in the forepart of the Larynx called Pomum Adami It has four Corners It is about an inch broad but not so long It 's Concave within and Convex without It is divided in the middle by a Line from its upper to its lower Part it s four Angles have each a small
side of the twelve Vertebrae of the Back they are crooked and like to the Segments of circles they grow flat and broad as they approach the Sternum but the further they are from it and the nearer they are to the Vertebrae they are the rounder and thicker at which end they have a round head which being covered with a Cartilage is received into the Sinus in the Bodies of the Vertebrae and at the Neck of each Head except the two last Ribs there is a small Tubercle which is also received into the Sinus of the transverse Processes of these same Vertebrae The Internal Superficies of the Ribs is smoother than the External they have each a small Canal or Sinus which runs along their under sides in which lies a Nerve Vein and Artery The Substance of the Ribs is partly bony partly cartilaginous which facilitates their Motion in Respiration At their cartilaginous end they are tied to the Sternum where they are harder in Women than in Men that they may the better bear the weight of their Dugs The Ribs are of two sorts the seven upper are called Costae Verae because their Cartilaginous ends are received into the Sinus's of the Sternum The five lower are called Falsae because they are shorter and softer of which only the first is joined to the Extremity of the Sternum the Cartilaginous Extremities of the rest are tied to one another thereby leaving greater space for the dilatation of the Stomach and Intrals The last of these false Ribs is shorter than all the rest it is not tied to them but sometimes to the Midriff and sometimes to the Musculus Obliquus Descendens The use of the Ribs is to contain and defend the Heart and Lungs to sustain the Muscles which move them in Respiration SECT XI Of the Breast Bone THE Sternum or Breast Bone is situated in the middle of the Breast Sternum it is composed of seven or eight Bones in Infants which at first are Cartilaginous but which harden and unite into three Bones after they are seven years old the Substance of these Bones is not solid but somewhat spongious The first and uppermost Bone is the biggest and largest it is uneven and rough on its outside but smoother on its inside where it has a shallow furrow which gives way for the descent of the Wind Pipe It has a Sinus lined with a Cartilage on each side of its upper end wherein it receives the Heads of the Claviculae The second is longer and narrower than the first and on its sides there are several Sinus's in which the Cartilaginous ends of the Ribs are received The third is shorter but broader than the second it receives into the Lateral Sinus's the Extremities of the last true Ribs it terminates into a Cartilage which hardens sometimes into a Bone called Cartilago Xiphoides or Ensiformis because it is broad at its upper end where it joins the third Bone and grows narrower to its Extremity where it is sometimes forked and sometimes it bends inwards compresses the upper Orifice of the Stomach and causes a great Pain and Vomiting The use of the Sternum is to defend the Heart and to receive the Extremities of the true Ribs SECT XII Of the Claviculae and Scapulae THE Claviculae or Channel Bones are two in number Claviculae situated at the basis of the Neck above the Breast one on each side they are pretty long and small at one end they are joined to the Production of the Scapula called Acromion by the Articulation called Synchondrosis at the other end to the upper end of the Sternum by the Articulation called Arthrodia they are crooked like an Italian S for the Passage of the Vessels which pass under them and to facilitate the Motion of the Arms. Their Substance is Spongious with a Cavity in their middle therefore they are the more easily broken and the sooner united when broken their use is to uphold the Arms to keep them at a little distance from the Sternum therefore Beasts which make not use of their Hoofs as Hands have no Claviculae whilst Apes Rats and several others which do use their fore Legs as we do our Hands have them The Scapulae 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 or Shoulder-blades Scapulae are two large and broad Bones like the Triangle called Scalenum they are situated on each side of the upper and back part of the Thorax their Substance is thin but solid and firm their outside is somewhat Convex and their inside Concave their upper edge is called Costa Superior and their lower Costa Inferior their broad end is called their Basis which with the two edges make the upper and lower Angles They have each three Processes of which the first runs all along the middle of their outside and 't is called their Spine That end of the Spine which receives the Extremity of the Clavicula is called Acromion The second Process is a little lower than the Acromion 't is short and sharp like a Crow's Bill therefore called Coracoides these two Processes are tied to one another by a strong Ligament which serves to keep the Head of the Humerus in the Cavity of the third Process which is called Cervix This Process is the Extremity of the Scapula which is opposite to its basis It has a pretty large and round Sinus tipt about its brim with a Cartilage which makes it the deeper it receives the head of the Humerus The use of the Scapula is to receive the Extremities of the Clavicula and Humerus for the easier motion of the Arm and to give a rise to the Muscles which move the Arm. SECT XIII Of the Bones of the Arm and Hand The Humerus THE first Bone of the Arm is the Humerus or Shoulder Bone 't is long and round its Substance or Fibres are pretty solid and compact it has a pretty wide and long Cavity in its middle in which is contained its Marrow At its upper end it has a round Head covered with a Cartilage which is received into the Cavity of the Neck of the Scapula but because this Head is much larger than the Cavity therefore it is surrounded with a strong Ligament which rises from the edge of the Cavity of the Scapula At its lower end it has two Protuberances the one External which receives the Extremity of the Radius the other Internal which is received into the Semicircular Sinus of the Vlna On the foreside of this Protuberance there is a small Sinus which receives the fore Process of the Vlna and on the backside there is another large Sinus which receives the Olecranium There is another small Protuberance on the side of this from which the Muscles that lie on the inside of the Arm arise The Vlna or Cubitus Ulna is a long and solid Bone with a Cavity in its middle It lies on the inside of the fore Arm reaching from the Elbow to the Wrist it
Line This Coat is loose and stretches very easily 't is not closely tied to the rest The second is a Web of small Vessels in form of a Net it furnishes the necessary Nourishment to the rest of the Coats The third is made of little Glands which separate the serosity of the Blood brought by the Vessels of the second Coat The fourth is composed of Muscular and Spiral Fibres whose Parts successively contracting hasten the Circulation of the Blood The only reason why the Veins do not beat as the Arteries do is because the Blood in the Veins runs from a narrow Channel into a broader whereas in the Arteries it runs from a wide Vessel to a narrower one Authors do not agree about the Origination of the Veins Some say that it is in the Heart and some others will have them to rise out of the Liver Others think that they come from all the Parts of the Body by their little branches which are distributed thorow it where they say they have their beginning as so many roots which join to make a Trunk or as little Brooks that produce a River But they have juster thoughts who think that they have no Origination at all no more than all the other Parts of the Body which are all formed in the Cicatriâ—â—lâ— of the Egg where they only grow and are insensibly disclosed The branches of the Veins in proportion as they recede from their Trunks they divide into an infinity of little Capillary branches which at last are imperceptible These Capillary branches are spread thorow all the Viscera in the Membranes and thorow all the Fibres of the Muscles to receive the Blood which was brought there by the Arteries The Extremities of the Veins unite to all the Extremities of the Arteries But because there are more Capillary Veins than Arteries the Veins unite with one another and so likewise do the Arteries that if one Branch be stopt the Blood may have a Passage by another These Unions Authors call Anastomosis The Veins have in their Cavities little Membranes or Valves disposed at certain distances in such a manner that they open towards the Heart and they shut towards the Extremities of the Body to hinder the Blood to return and to sustain it that by its weight it fall not back again There are more Valves in the Veins of the Thighs Legs Feet and of the Arms and Hands than in the other Parts of the Body There are none in the Vena Porta the Emulgent Veins nor in the Vena Pulmonaria The openings of the Valves are disposed alternatively to the end that the Blood which escapes or falls back from one may be stopt by the next Their Figure is almost like a Half-Moon their Substance is membranous fine and strong their number is uncertain The use of the Veins is to bring the Blood back again to the Heart from all the Parts of the Body SECT V. Of the Vena Porta ALL the Veins rise from two principal Trunks viz. The Porta and the Cava except that of the Lungs which is a particular Vein and separate from the rest The Vena Porta was so called by the Ancients because they thought that it brought the Chyle by its Meseraick branches from the Intestines to the Liver thorow whose Substance 't is spread as is said in the Section of the Liver It rises out of the Liver it sends out two small Veins to the Vesica Fellis called Cysticae Gemellae one to the Stomach called Gastrica Dextra then advancing a little to the left its trunk divides into two branches of which the least called Ramus Splenicus goes to the left Hypochondrium And the greatest called Mesenterica goes to the right The Ramus Splenicus so called because it carries the Blood from the Spleen sends out from its Trunk two branches called Gastrica Minor Maâ—â—â— which are spread thorow all the Stomach A branch of the Gastrica Major makes the Coronariae Stomachicae at the upper Orifice of the Stomach It gives three branches more two to the Omentum and Colon and the third to the Pancreas Then the Splenicus divides into two branches the one Superior the other Inferior The Superior sends out the Vas Breve and some other branches which go to the Spleen The Inferior gives two branches viz. The Epiplois Sinistra which is spread thorow the back Part of the Omentum and that Part of the Colon which is under the Stomach The other branch is the Gastro-Epiplois Sinistra which is also spread upon the Omentum and upon the Stomach it makes sometimes the Vena Haemorrhoidalis Interna The rest of this Inferior branch enters the Substance of the Spleen The right branch of the Porta called Vena Mesenterica before it divides sends out the Gastrâ—-Epiplois Dextra which is spread in the Omentum and lower Part of the Stomach it sends out also the Intestinalis which goes to the Duodenum and to the Jejunum it gives some branches to the Omentum and Pancreas Then the Mesenterica divides into three great branches which run betwixt the Duplicature of the Mesenterium two of them go towards the right side which divide into fourteen branches and these are again divided into an infinity of others less which are called Meseraicae they creep upon the Jejunum Ilium Caecum and Part of the Colon. The last and third branch of the Vena Mesenterica is spread thorow the middle of the Mesenterium to that Part of the Colon which is on the left side to the Rectum down to the Anus where it forms the Haemorrhoidales Internae The Use of this Vein is to bring back to the Liver the Blood which was brought by the Arteries to these several Parts SECT VI. Of the Trunk of the Cava Ascendens ALL the little Capillary branches of the Vena Cava which are spread thorow the Substance of the Liver unite by little and little into others which grow bigger and as they approach the Convex side of the Liver where they join all together and make up one large Trunk which comes out of the Liver and divides into two great big branches one of which goes towards the Heart and forms the Trunk called Ascendens the other goes downwards and is called Descendens Both the one and the other lie upon the Body of the Vertebrae on the right side of the Porta The Vena Cava Ascendens goes to the Claviculae before it divides but as it ascends to them it casts out three branches on each side The Phrenica or Diaphragmatica the Coronaria and the Intercostalis Superior Besides these three it sends out the 〈◊〉 〈◊〉 〈◊〉 〈◊〉 〈◊〉 or Vena fine Pari on the right side only The Phrenica comes from the Cava where it pierces the Diaphragma upon which it is spread It casts some branches to the Pericardium and Mediastinum Some Authors think that 't is by this Vein that the Pus of an Empiema is carried to the Kidneys and Bladder