Anatomyand Leonardo daVinci - Semantic Scholar · Anatomyand LeonardodaVinci AntonyMerlin Josea ... Leonardo's notebooks! Armed with his irrepressible spirit of inquiry, Leonardo

YALE JOURNAL OF BIOLOGY AND MEDICINE 74 (2001), pp. 185-195.Copyright © 2001. All rights reserved.

THE ARTS IN MEDICINE

Anatomy and Leonardo da Vinci

Antony Merlin JoseaYale School of Medicine, New Haven, Connecticut

Leonardo da Vinci was born on the15th of April, 1452, during the great"rebirth" - the Renaissance. He was bornin the country village of Vinci, which lieshigh up on the Mount Albano, in the valleyof the river Arno, dividing Florence fromPisa. This lovely village remains un-spoilttoday. He was the son of Caterina, a peas-ant girl. He was illegitimate. His father,Ser Piero da Vinci, the son of a Florentinelawyer, was quickly persuaded to marryinto a good family. His mother was mar-ried off to a cowherd. Nothing more isknown of her, though forty years laterLeonardo notes down paying the funeralexpenses of a woman called Caterina, whomay have been his mother. Leonardo'sgrandparents immediately took Leonardointo their care. However, after a few years,Ser Piero realized that his wife, DonnaAlbiera, would bear him no children.Meanwhile the young Leonardo wasgrowing into a beautiful and promisingchild and so Ser Piero took his natural soninto the family.

The innate skills that Leonardo daVinci possessed are best illustrated by thewords of Leonardo's famous biographer,Giorgio Vasari, when he speaks of youngLeonardo:

In arithmetic, during the few months he stud-ied it, he made such progress that he fre-quently confounded his master by raisingdoubts and difficulties. He devoted some timeto music and soon learned to play the lyre,and being filled with a lofty and delicate spir-it he could sing and improvise divinely on it.Yet though he studied so many differentthings he never neglected drawing and work-ing in relief, these being the things whichappealed to his fancy more than any other [1].

The education of this extraordinarychild was unusual because he was nottaught Greek or Latin. This made it diffi-cult for him to mix with the learned peopleof Florence. He regretted this and tried toteach himself. His early notebooks containlong lists of Latin words. But there are nolists of Greek words. He must have foundthis language too difficult. One gift absentin Leonardo, and the one from which hesuffered, was the ability to learn lan-guages. He wrote:

I am fully aware that the fact of not being aman of letters may cause certain arrogant per-sons to think that they may with reason cen-sure me, alleging that I am a man ignorant ofbook learning. They will say that because ofmy lack of book learning I cannot properlyexpress what I desire to treat of. Do they not

a To whom all correspondence should be addressed: Department of Molecular Biophysicsand Biochemistry, 333 Cedar Street, RO. Box 208024, New Haven, CT 06520-8024. E-mail: [email protected].

185

186 Jose: Anatomical drawings of Leonardo da Vinci

know that my subjects require for their expo-sition experience rather than the words of oth-ers [1]?

In spite of this limitation (or perhapsowing to it), Leonardo grew to be a self-taught giant in science, with interestsspanning almost all fields of this subject.Every field that Leonardo was interestedin, he made important contributions to.Some idea of how good an inventor he wasis given in the letter that he wrote toLudovico Sforza, Duke of Milan, in about1481, offering his services. Here, Leonar-do wrote:

When a place is besieged I know how toremove the water from the moats and make aninfinite number of bridges, covered water-ways, ladders and other instruments suitablefor the said purposes. I have also plans ofmortars most convenient and easy to carry,with which to hurl small stones similar to astorm and with their smoke cause great terrorto the enemy and great damage and confu-sion. And if it should happen that the fightwere at sea, I have plans for may instrumentscapable of offense and defense, and vesselswhich will resist the fire of the largest can-non, powder or smoke. Also I will make cov-ered cars, safe and unassailable which willenter among the enemy with their artilleryand will break up the largest body of men.And behind these the infantry will be able tofollow unharmed and without any opposition.Also if need shall arise I can make cannon,mortar and light ordinance of very useful andbeautiful shapes, different from those in com-mon use. In times of peace, I believe I cangive perfect satisfaction, equal to that of anyother in architecture and the construction ofbuildings both private and public, and in con-ducting water from one place to another.Also, I can carry out sculpture in marble,bronze or clay; similarly in painting I can dowhatever can be done as well as any otherwhoever he may be. Moreover, the bronzehorse may be taken in hand, which shallendure with immortal glory and eternal honorthe happy memory of the Prince your father,and of the illustrious house of Sforza.

And if any of the aforesaid things shouldseem impossible or impracticable I offermyself in readiness to make a trial of them in

your park or in whatever place may pleaseyour excellency, to whom I commend myselfwith all possible humility [1].

One of the most astonishing thingsabout this letter is that drawings for everyone of these claims can be found inLeonardo's notebooks! Armed with hisirrepressible spirit of inquiry, Leonardomade many important contributions in avariety of fields. Here I shall focus on hiscontributions to the field of anatomy,which was fueled further by his passionfor painting and sculpture. I shall highlightsome of the important technical innova-tions and discoveries made by Leonardo inthe anatomical method and illustrativetechniques and also present an analysis ofa select few of his anatomical sketches,which exemplify the technique, accuracy,and clarity of Leonardo's work, and at thesame time underscore some of the contem-porary influences.

THE REIGN OF GALEN'SANATOMY

A just estimate of Leonardo's contri-bution to anatomy can only be arrived atwhen the state of the science in his day isunderstood.

With the death of Galen at the end ofthe second century, the study of anatomyentered upon its dark days and for nearlythirteen centuries scarcely a single factwas added to the knowledge of the struc-ture of the human body. During theseyears, people, for their knowledge of nat-ural phenomena, were content to rely uponthe writings of the Fathers, these state-ments in turn being based upon those ofearlier writers, which were both corruptedand diluted as it was passed on down thegenerations. Under such circumstances,there was naturally no incitement to per-sonal observation, and experiment and sci-ence languished.

During these times, for a physician,an intimate knowledge of anatomy was

Jose: Anatomical drawings of Leonardo da Vinci 187

unnecessary; if he knew the positions ofthe individual organs and their presumedfunctions, he had all that he required, andthis he could obtain from a translation ofan Arabic summary of Galen's anatomicaltreatises, such as is found in Avicenna'sCanon. So the study of anatomy becameconventionalized into the reading of atranslation into Latin of an imperfect sum-mary by an Arab of Galen's teaching, andsince it was Galen, the complete submis-sion to the dictates of antiquity that char-acterized the Middle Ages gave it anauthority and finality that well-nigh sup-pressed all stimulus for further inquiry.Indeed, ignorance of the original treatisesconcealed the fact that Galen's contribu-tions to anatomy were based on dissectionof animals, chiefly monkeys, that hisanatomy was not really human anatomy.When this fact was revealed by the inves-tigations of Vesalius in the sixteenth centu-ry, their unshaken confidence in the infal-libility of Galen led at least one Galenist tothe conclusion that the structure of thehuman body must have altered materiallyin some respects during the centuries thathad elapsed since Galen's day!

TECHNICAL INNOVATIONS INANATOMY

"This my illustration of the humanbody shall be demonstrated to you, nototherwise than if you had the real manbefore you" [2].

Leonardo's opportunities for anatomi-cal studies were no better than those avail-able for others of his time. Why then didhe, an artist, far excel in his results beyondeven the professed anatomists who werehis contemporaries? The answer is to befound in the spirit of the man and in themethods employed. He was in possessionof an overmastering desire to know allthings, to prove all things for himself,while his contemporaries were content torely more or less implicitly on the state-

ments of their predecessors and to inter-pret what observations they might make inaccordance with those statements.

Leonardo's methods of acquiringknowledge were observation and experi-ment. In his early youth as a student of artin Verrocchio's bottega in Florence,Leonardo learned topographical anatomy,the study of the underlying structures thatmold the human form, a study of great useto the artist [3]. But for Leonardo the studyof anatomy became a science. In it hecombined the study of structure, revealedthrough the quick eye and through hishabit of precise artistic portrayal, with astudy of function. He never did separatefunction from structure in his thinking.

In Leonardo's drawings of the humanbody, man lives, functions, and changes.Leonardo, the artist, renders these humanfigures in their most subtle spiritualexpression. He succeeds, too, in showingthe human form in quick motion, in vio-lent motion, and in dramatic emotion.Behind all this is correct dynamic anato-my. All depends on the correct depictionof the functioning human frame. The useof the limbs and their working are to him amechanical performance that is worthy ofdeep study. Leonardo's insatiable desire toknow and his penetrating intelligence con-verted Leonardo the Artist into a Scientistnow traveling along unexplored roads.

As Leonardo progressed in hisanatomic studies, he realized that hisinvestigation must comprise the study ofthe body from babyhood to old age andmust include even the study of a fetus in itsvarious stage (see below for a drawing of afetus in utero). His general plan for thisanatomy was to study each part, from thebones outward to the skin. Presentingviews in rotation of each part, and in thecase of the bones, in addition to those fourviews, a cross-section and a longitudinalsection. At the end of his work, when hewas an old man living in Clos Luce inFrance, he told De Beatis, who visited his


studio, that he had dissected thirty bodies.The evidence shows that he also studiedthe bodies of animals, including pigs in theslaughterhouse immediately after theywere killed. His favorite animal was theox.

In his notes, Leonardo tells of dissect-ing in the hospital of Santa Maria Nuova inFlorence. He also may have participated inthe public dissections of Santa Crocewhich, according to the diary of the shop-keeper Landucci, took place in Florence inJanuary of 1505. Leonardo is known tohave dissected in the hospital Santo Spiri-to in Rome. He records having had to dis-continue his work in this hospital when the"German deceiver," the mirror-maker Gio-vanni, who had been assigned by the Popeto help him, "hindered him in anatomy."

Leonardo often explains the advan-tage of pictorial over mere verbal demon-stration. He states:

With what words, 0 writer, can you with likeperfection describe the whole arrangement ofthat of which the design is here? ... How inwords can you describe this heart without fill-ing a whole book? Yet the more detail youwrite concerning it, the more you will con-fuse the mind of the hearer [2].

Although Leonardo emphasizes picto-rial description, his own word-descriptionsare remarkable for their clarity and brevi-ty, which is in marked contrast to theinvolved "scientific prose" of his contem-poraries.

Leonardo describes dissection bymorselment, removing little by littleminute portions of adventitious materialfrom the vicinity of special structuresunder study within the body, preparing theexposed material left behind for demon-stration and for sketching, much as is donetoday. No method of artificial preservationof the anatomic material thus under studyis mentioned.

The purpose of Leonardo's drawingswas to reveal structure and sometimesfunction through visual demonstrations of

the actual dissected material. He said thathe combined in each single drawing theexperience from a number of dissections.He found ingenious ways of demonstra-tion never used before to show simultane-ously in one drawing not only what he hadexperienced in various dissections but alsothe various layers of the dissected speci-men that could not be shown in a straightsurface view. He thus maintained the char-acteristics of a study from nature. He sel-dom used diagrams.

In Leonardo's bones a lifelike por-trayal is given to all of his pictures throughthe representation of proper carrying andsupporting angles which are correctlyshown, thus creating realism even in hisskeletal drawings. Leonardo illustratedevery bone in the body. He demonstratedthe actions of the bones as levers whenacted upon by muscles. He illustrated forthe first time the proper double curvatureof the spine, the true tilt of the vertebrae,accurately portraying each, especiallythose of the cervical spine and sacrum.

He described the teeth, presentingtheir proper number, strangely a matter ofdispute then! Demonstrating the antra inthe skull he shows the upward projection ofthe teeth of the upper jaw into the floor ofthe maxillary sinus. He was the first toshow accurately the bones of the hand. Hesaid that he had observed twenty-sevenseasmoid bones, and he presented themechanical principles by which thesebones function. Leonardo stated that it wasnecessary to saw the bones longitudinallyand also in cross-section in order properlyto study their structure. Thus in sectioningthe skull he discovered the spaces withinthe bones of the skull known as the sinusesand demonstrated for the first time themaxillary sinus or the antrum of Highmoreand the teeth of the upper jaw which enterit.

As visual aids Leonardo used ropestrands to indicate the direction, origin,and attachment of the muscles. He realized


that in the body muscle groups are bal-anced, an anterior group against a posteri-or group, and he ingeniously used cordand wire ion diagrams to represent musclegroups as a means of clarifying theiraction. This is the first use of this methodof illustration in the history of anatomy.

Leonardo presented drawings asseeming transparencies. This method ofshowing visceral layers of organic struc-ture as if transparent with overall outlineof the parts removed in dissection, inge-niously anticipates modem principles ofdidactic demonstration. At an age when X-rays were not known and not even dreamtof, Leonardo's power of imaginationseems miraculous. In the famous drawingof the legs he indicates for the first time inthe history of anatomy the correct positionof the femur.

Leonardo was the first to depict cross-sectional anatomy. Here again he used theprinciple simultaneously showing in thepictorial demonstration what the eye is notable to discern at a glance. The surface ofeach cross section is shown within thecontour of the limb from which it is taken.In Leonardo's studies of the complicatedstructures of the shoulder girdle and in thestudies of the bones of the foot, he usedexploded views with guide lines to indi-cate the source of the elevated structures,another innovation now often used to illus-trate the relation of the parts in complicat-ed machinery. Equally ingenious were hisglass models of the heart to show theaction of the valves. These were three-dimensional objects for demonstration,similar to those used today.

Leonardo experimented with animals,for the most part they were cadavers, butthese animal experiments led him to someof his most important discoveries. Leonar-do pithed a frog spinal column and there-by was able to demonstrate the abolition ofthe frog's spinal reflexes. He inflated andthereby forcibly deflated the lung of agoose, producing the characteristic goose

"honk," in the study of the mechanism ofvoice. He studied the pierced hearts of pigsin Tuscany at their slaughter, demonstrat-ing by this means the coincidence of threeevents: the pulse wave in the arteries, thebeat of the heart against the chest wall, andthe systolic contraction of the heart. Hisconclusions were a tremendous departurefrom the established opinion of the day.

In the muscular system Leonardo sug-gested a system of nomenclature for themuscles which would use a separate namefor each muscle, a name designed toexpress its origin, insertion, direction ofpull, and purpose. He defined for each sep-arate muscle an individual innervation,individual blood supply, separate origin,insertion, and purpose.

Leonardo identified the muscles ofthe face. He described the action of mus-cles in general as a pulling action, the mus-cle using its force to pull along the line ofits length. The exceptions to this pullingaction were the tongue and penis whichpush. He stated that muscles do not movethe member to which they are fixed at theirorigin but that they move it at their point ofinsertion, to which the sinew which leavesthe muscle is attached. He also stated thatmuscular movement is by a continuousinfinity of successive phases of motion. Heindicated that posture is maintained by aconstant interplay of reciprocally antago-nistic muscles. He described the deltoid asa separate muscle and stated that the pec-toralis minor had as its primary action anaccessory muscle of respiration pullingupward upon the rib cartilages.

He illustrated the biceps as being thechief supinator of the forearm, showingthat it is only secondarily a flexor; he alsoshowed that the pronator teres is its antag-onist in action to pronate the arm. Hedescribed the restriction of rotation of theforearm with the arm in flexion as havinga radius of one-half a circle while theextension of three-fourth of a circle canbe effected. He stated that four muscles


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Figure 1. Representations of humanfetus at term and of ungulate placenta.The Royal Collection © 2001, Her MajestyQueen Elizabeth 11.

control the action of the eye. He identi-fied the heart muscle and, following hisown criteria, searched for a nerve supplyto this muscle, finally deciding upon theleft branch of the vagus as the nerve ofthe heart.

THE DRAWINGS

Figure 1 is the first ever, clear repre-sentation of a human fetus in utero. In thiswonderful drawing of the fetus still withinthe womb, it is curious to note cotyledonsof the ungulate type on the walls of theuterus, while the discoidal placenta isentirely overlooked, even though there is amemorandum to "Note well the umbilicalvein where it ends in the uterus." It is evi-dent that Leonardo had examined a preg-nant human uterus at full term- he givesa number of drawings of the fetus as it liescurled up within the womb- but in none

of them is a placenta shown. Where theuterus is also shown there is usually noindication of how the fetus is connectedwith it; only in the above figure are thecotyledons represented, on the assumptionthat what he had seen in the cow occurredalso in the human pregnant uterus.

The structure of the cotyledons inter-ested him greatly. He recognized that atbirth each cotyledon divides, part remain-ing connected with the uterus and partadhering to the chorion, and provides fig-ures showing the separation (not shownhere), but is somewhat uncertain of theirstructure. He perceived that half of eachcotyledon remains a fetus "When it is borncovered," that is to say in a "caul," and theother half remains with the uterus. Hisunderstanding of embryology was derivedfrom both dissections of animals (the oxbeing his favorite) and from the dissectionof at least one pregnant woman at term.He was also able to deduce function frommany of his embryological studies, forexample, stating that, "The beating of the

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heart and the breathing of the motherserve also for the child joined to her by theumbilical cord."

The situs drawing, Figure 2, repre-sents a mixture of traditional notions andaccurate observation. The heart is the twochambered heart of the ancients with athick ventricle and, as in an ox, moderatorbands in both ventricles. The vena cavaopens directly into the right ventricle. Thebranching of the aorta are similar to thoseof the ox. The large, possibly pregnant,uterus has a single cavity, but the scal-loped edges of this cavity are remnants ofthe seven cells of Michael Scott.

The tubular structures seen to emergefrom the lateral walls of the uterus are theuterine cornu of earlier authorities. Thelong wandering blood vessels carrying theretained menses of the pregnant womanfrom the uterus to the breast for the manu-facture of milk are also shown.

Yet, even with its many throwbacks toGalenic authority, Leonardo's demonstra-tion represents an astonishing advancewhen compared with illustrations currentin his day. With his situs figure as a start,Leonardo was soon to advance into a myr-iad of new observations in all of the sys-tems, which his dissections laid bare. It islittle wonder that with his almost dailyexcursion into the world of the unknown,Leonardo was unable to crystallize histhoughts into copy for printed presenta-tion; so his great work remained as labo-ratory notes only.

It was Leonardo the artist rather thanLeonardo the anatomist who was domi-nant in the endeavor to formulate a canonof the proportions of the human body. Hewas indebted to the Roman writer Vitru-vius, who in the reign of Augustus, wrotea treatise on architecture in which headvocated the observance of a definitesymmetry in the various parts of an archi-tectural design, and advanced in support

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Figure 3. Human figure in a circle in asquare, illustrating its proportions. Art-today-com © 2001.

of this idea the fact that such symmetryoccurred in natural objects. As proof ofthis he gives the proportional lengths ofseveral parts of the human body, pointingout for example that the length of the bodyis eight times the height of the head fromthe point of the chin to the vertex and sixtimes the length of the foot. The drawingsin Figure 3 are evidently illustrations byLeonardo of two of Vitruvius' proportions,namely that in which he states that in aman standing erect with the arms stretchedhorizontally, the distance between the tipsof the fingers will be equal to the height ofthe body and the figure may therefore beinscribed within a square, and secondly, ifa man lie supine with arms and legsabducted, a circle drawn with the umbili-cus as the center will touch the tips of thefingers and the toes.

In the words of Leonardo:


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Figure 4. Above, a supposed arrange-ment of intestine and stomach. Below,left, stomach, liver, and spleen with splenicvein. Below, right, the caecum and appen-dix. The Royal Collection 0 2001, HerMajesty Queen Elizabeth II.

The span of a man's outspread arms equalshis height. If you open your legs so as todecrease your height by 1/14, spread out andraise your anms so that your middle fingersare level with the top of your head, you willfind that the navel will be the center of a cir-cle of which the outspread limbs touch thecircumference; and the space between thelegs will form an equilateral triangle [I](These words can be seen in Figure 3.)

Leonardo thus often extended thecanon of proportions that were propound-ed earlier, deriving for himself artistic".rules of proportion" for the representa-tion of the human formn. He also made astudy of the proportions of the humanface, and arrived at the most acceptableproportions that would result in a beautifulface (akin to the studies of Francis Galtonon beauty). He then used these rules and

distorted them on purpose to arrive at dis-proportionate faces, which he sketched outas the famous series of da Vinci'sgrotesques.

Leonardo's figures illustrating thedigestive system are fewer in number thanthose of some other portions and probablyall were made at an early period, but nev-ertheless even the poorest of his drawingsare superior to those that were currentthen.

Figure 4 is not exactly that of ahuman stomach. The esophagus graduallywidens as it approaches the stomach, sothat there is no abrupt transition from oneto the other as in man, and the fundus ofthe stomach is not so sharply defined, eventhough the esophagus opening is some-what farther to the right than is usual. Butmore striking is the course of the pyloricend and first portion of the duodenum. Inthe majority of the figures, instead of pass-ing upward, backward, and to the right,the direction is upward, backward, and tothe left, so that the duodenum descendsbehind the stomach and makes its appear-ance from behind it opposite the middle ofthe greater curvature.

In man, it is true, the esophagus doesenlarge in its subdiaphragmatic to formwhat has been termed the cardiac antrum,but its union with the stomach is abruptand not gradual as Leonardo depicts it.One must suppose that Leonardo wasdrawing what he was seeing, and accord-ingly one must suppose that he was notrepresenting a human stomach, but that ofsome animal, the pig most probably sinceit presents the peculiarities that Leonardofigures.

However, he had an understanding ofthe function of the digestive system, forexample, he probably observed the peri-staltic contraction of the esophagus, for hewrites:

Since all the muscles have a dilating andextending motion, note, in making the anato-


my, there are the nerves which, between theesophagus and the cervical vertebrae, enterthe muscles in that place (i.e., the esophagus),which by their dilation constrict and closesuccessively the esophagus when food is pro-pelled through its narrow canal to the stom-ach; so in this case be diligent to note everyleast circumstance [4].

Figure 5 was drawn with red crayonand subsequently outlined with ink. It rep-resents a sagittal section through the skull,with labels indicating the various struc-tures cut, and is the translation into draw-ing of a description by Avicenna. On thesurface there are the hairs (capigli) of thescalp; beneath these a layer termed thecodiga, corresponding to the epidermisand the superficial fascia; then follow thegalea aponeurotica, termed however,came musculosa; then the pericranium,the layer of areolar tissue being disregard-ed; then the bony cranium; then in succes-sion the dura mater, pia mater and brain(celabro). Nothing of the structure of thebrain is shown except the ventricles, andthese are represented as three cavities sep-arated by constrictions and placed in arow, one behind the other, a prolongationof the anterior one extending into the eyeand probably represents the optic nerve.Though in Figure 5 Leonardo has reliedlargely on prior authority, he had laterrefined the representation of the ventriclesby injecting wax into the brain.

Of the parts of the brain other than theventricles, Leonardo gives little informa-tion. In the basal views of the brain of anox, the temporal lobes of the cerebralhemispheres and the cerebellum are clear-ly shown, and the infundibulum, cutacross and surrounded by the retemirabile, is indicated in one figure, whilea T-shaped structure projecting from thethird ventricle may represent the hypoph-ysis. These, together with the ventricles,form the sum total of Leonardo's contri-bution to the structure of the brain.

The mechanics of the movements ofthe head upon the summit of the vertebralcolumn exercised him not a little, since heseemed to associate with these movementsa necessity for a considerable rigidity ofthe column, inasmuch as the muscles thatproduced these movements rise from thevertebrae. How the rigidity could beimparted is illustrated by Figure 6, inwhich the muscles are represented bystout cords, and concerning which hewrites:

First you will make the spine of the neck withits tendons, like the mast of a ship with itsstays, without the head; then make the headwith its tendons that give it movement on itspole [4].

The cords cannot be identified withany actual muscles, and the figure must beregarded as a representation of an idearather than of actual conditions. At first he

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Figure 5 Section through the skull andbrain showing brain membranes. TheRoyal Collection © 2001, Her MajestyQueen Elizabeth 1II


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Figure 6. A cord diagram of the musclessupposed to stabilize the cervical ver-tebrae in movements of the head. Also,a sketch showing the insertion of mus-cles into the spine of a vertebra. TheRoyal Collection © 2001, Her MajestyQueen Elizabeth 11.

supposed that the stabilizing musclespassed from the cervical vertebrae to theshoulder girdle, but later on, when hereturns to the idea of the mast and its rig-ging, he concludes that:

The muscles of the shoulder do not aid (in thefixation of the vertebrae), nor those of theclavicle (forcula), since the man will relaxthese muscles arising in the shoulders andforcula when he raises the shoulders to theears and will take away the power of his mus-cles. And with such relaxation and shorten-ing, movement is not wanting in the neck(head?) and there is not wanting the resis-tance of the spine in sustaining the head [4].

Then he proceeds to assign the mainstabilizing action of the superior posteriorserratus, which he invariably describes asformed of three separate slips.

This figure illustrates one of daVinci's unique attributes. He attempts to

ascribe function and draws heavily fromhis architectural and inventive abilities.This is most profound in his drawings ofthe musculo-skeletal system.

Figure 7 shows the earliest knowndrawings of the coronary arteries. In thesedrawings both the left and the right coro-nary arteries are shown sending theirbranches to the muscles of the heart.These are followed in detail. Leonardoshows the coronary arteries "crowning"the top of the heart. This is how they gottheir name "coronary." It is noteworthythat neither in his figures nor in his textdoes Leonardo take definite cognizance ofthe atria of the heart. He figures in somecases the auricles (as above) and speaks ofthem in various passages as orecchi oradditamenti del core, this latter termrecalling their Avicennian description; butof the more important atria never a word.

In his discussion of the heart Leonar-do was the first to state that it is composedof muscle; he was the first to describe it asbeing four-chambered. Leonardo saw anddrew the auricles correctly, depicting themas receiving chambers for the peripheralblood. He maintained this idea in hisdescriptions and showed it in his draw-ings.

Speaking of an "old man" who diedquietly while conversing with him at hisbedside in the hospital, Leonardo states:

And when I opened the body in order toascertain the cause of so peaceful a death, Ifound that it proceeded from weaknessthrough failure of blood and of the artery thatfeeds the heart and the other lower members,which I found to be parched and shrunk andwithered; and the result of this autopsy Iwrote down very carefully and with greatease, for the body was devoid of either fat ormoisture, and these form the chief hindranceof its parts. The other autopsy was on a childof two years and here I found everything thecontrary to what it was in the case of the oldman. The old who enjoy good health diethrough a lack of sustenance. And this isbrought about by the passage to the mesaraic


Figure 7. Mechanisms of the ventricles of the heart. The Royal Collection © 2001, HerMajesty Queen Elizabeth 11.

veins becoming continually restricted by thethickening of the skin of these veins; and theprocess continues until it affects the capillaryveins, which are the first to close up alltogether" [2].

These observations make Leonardothe father of a modem branch of medicine;gerontology. His dissection of the old manyielded him a large number of pathologicfindings associated with arteriosclerosis,the significance of which he did not fail topoint out:

The artery and the vein which in the oldextend between the spleen and the liver,acquire so great a thickness of skin that itcontracts the passage of the blood that comesfrom the mesaraic veins, through which thisblood passes over to the liver and the heartand the two greater veins, and as a conse-quence through the whole body; and apartfrom the thickening of the skin these veinsgrow in length and twist themselves of themanner of a snake and the liver looses thehumor of the blood which was carried thereby this vein; and consequently this liverbecomes dried up and grows to be like frozenbran both in color and substance" [2].

The last of his written notes reads:"June 24, 1518, Saint John's Day, atAmboise, in the palazzo of Cloux; I shallgo on" [1]. This intellectual giant whoarguably did more in one lifetime than anyman parted in all humility saying, "I haveoffended God and mankind because mywork did not reach the quality it shouldhave" [5].

REFERENCES1. Keele, K. Leonardo da Vinci and the Art of

Science. River Forest, Illinois: PrioryPress, Ltd.; 1997.

2. Belt, E. Leonardo the Anatomist.Lawrence, Kansas: University of KansasPress; 1955.

3. Vasari, G. Le Vite de piu Eccellenti PittoriScultori e Architetti. Milanesi, Florence:Sansoni; 1906.

4. McMurrich PJ. Leonardo da Vinci - TheAnatomist. Baltimore: Williams andWilkins; 1940.

5. Frequently quoted apocryphal remark.

Anatomyand Leonardo daVinci - Semantic Scholar · Anatomyand LeonardodaVinci AntonyMerlin Josea ... Leonardo's notebooks! Armed with his irrepressible spirit of inquiry, Leonardo

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