H O W B R A N C H E S O F T H E V E N A C A V A A R E J O I N E D

T O O F F S H O O T S O F T H E P O R T A L V E I N I N T H E S U B S T A N C E

O F T H E L I V E R , A N D H O W T H E V E N A C A V A C O M E S O U T

O F T H E L I V E R O R D I S T R I B U T E S B R A N C H E S I N T O I T

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called hanabub, “vein with a belly”; by latin authors cava, magna, and iecoraria, less often caudicis vena.27 i do not understand why many have written that galen called it the “common vein,” though i think they confused it with the vein in the forearm (α) [vena mediana antebrachii] that learned physicians call by that name. so too hip-pocrates called the axillary vein of the right forearm “hepatic”28 (the left axillary is marked r, u), the same term he applied to the vena cava itself where it is closest to the heart. the branches of the vena cava that extend through the body of the liver lie upon branches of the portal vein (Z lies on Y in fig. 13, bk. v),29 and the ends of the small branches of either vein converge closely at their mouths30 so that the branches of the vena cava speedily and perfectly absorb the blood developed by the liver in the branches of the portal vein – and purged of yellow bile and clouded blood – and then carry it to the entire body to nourish the parts. the convergence of the veins con-stituting the vena cava and coming out of the liver does

not take place in the middle of the liver’s convexity, as the mass of Anatomists are silly enough to believe. As i previ-ously stated, this happens in the part of the liver that is closest to the right side of the dorsum or spine. conse-quently, no part whatever of the substance of the liver is seen to cover the entire posterior part of the vena cava where it faces the backbone. nor, once again, as it seemed to galen and all professors of anatomy until now, do the branches of the vena cava coming out of the liver make up the vena cava in the same way as31 the portal vein was said to be formed and assembled (B is made up of A A and then 1–5 in the figure of ch. 5), or as we see that roots belong to a tree’s trunk. the branches of the vena cava constitute it32 as if entering a vein running more or less straight down-ward through the back of the liver and attached only to a

depression in the liver. these are the two larger branches (one of them marked A) near the top of

the liver, entering the front of the vena cava but not its sides or

the back; they are not at all comparable in size to the

27 “Vein of the stem.” The 1555 edi-tion omits the next two sentences that follow.

28 V. basilica, called “hepatic” prob-ably because it was the vein phle-botomized for treatment of liver ailments. But Vesalius’ statement here is anachronistic, coming from medieval venesection lore unat-

tested in the Hippocratic writings, or attributed to Hippocrates by Galen or Pollux. For what the Hip-pocratics actually wrote about bloodletting, see Brain, 1986, pp. 112–121.

29 Z; a branch of the hepatic vein lies upon Y, a branch of the portal vein.

30 The lines that follow were revised in the 1555 edition: “and appear to those who dissect them now in many places to converge and join. The final convergence and meeting of branches into the stem of the vena cava does not take place in the middle of the liver’s convexity,” etc.

31 The 1555 edition omits this refer-ence to the portal vein.

32 In the 1555 edition, the verb is “join it,” ipsi continuantur instead of eam constituunt.

This figure illustrates the convexity of the liver and its posterior side. a and a

indicate the upper region of the lobe contermi-nous with the transverse septum [diaphragma] toward

the front; B and B mark the lower region. c marks the part of the vena cava where it permeates the septum and extends branches to it. d to e marks the area where the vena cava is attached to the substance of the liver. H shows a small portion of the portal vein. Other characters are referred to elsewhere than in the present chapter.

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vena cava. indeed, if – like me – you do not put the utmost faith in the words of galen and do not distrust your eyes, you will doubtless say that the vena cava passes down from the heart through the back of the liver, and that two large veins [v. hepatica dextra, v. hepatica sinistra] sprout from its anterior and are diffused with many branches into the substance of the liver.33 in addition to the veins that the vena cava presents to the liver as soon as it attaches to the substance of the liver in its descent from the heart, in the rest of its descent (which is extremely short) through the back of the organ you will also see very small branches (a) running from the front of the vena cava also into the substance of the liver. there is not the same number of these in all humans. they are all so easy to see when dis-secting a human carefully that anyone who now looks at the sys-tem of the vena cava will agree more than ever that so far as con-cerns its distribution but not the course of blood, it should be described first from the heart, and

afterward its course upward and downward should be explained.34 but since i grant that the blood contained everywhere in the vena cava is made by the liver, i have begun the distribution of branches of the vena cava more or less from the liver; then i shall describe first the part of the vena cava that stands above the liver, not that portion extending to parts beneath the liver, putting far behind me all disputes about the origin of the vena cava. neverthe-less, i advise all who take a serious interest in the matter to place no trust in the views of any authors, but to make careful dissections not only of the human liver but also of apes and dogs,35 in which the shape of the liver and the system of branches from the vena cava into the liver are different. they should also examine the course of the vena

cava near the liver and the heart, if they enjoy as well the part of Anatomy that is not applied. by what technique this should be done will be explained partly at the end of the fifth book and partly at the end of the sixth.

33 1555: “and connected to small branches of the portal vein.”

34 The end of the chapter from this point is abbreviated and rewritten in the 1555 edition as follows: “But since we still agree with Galen that

the blood contained everywhere in the vena cava is made by the liver, we have begun the distribution of branches of the vena cava from the liver more or less as he did, and shall next describe that part of

the vein which stands above the liver.”

35 As symbolized by the animals pres-ent at the human dissection on the title page, Vesalius recommends some hands-on comparative anat-

omy as fundamental to his educa-tional method.

36 Corrected to “left” in the 1555 edi-tion.

This figure shows the portion of the vena cava running along the back of the liver. I have dissected it with a long incision along the back of the vein and then spread it open to show the openings for the branches that the vena cava sends to the liver, or which constitute the vena cava. The a’s mark the

opening of the branch distributed from the vena cava to the left side of the liver [lobus hepatis sinister], and the branch itself; B and B mark the branch distributed through the right36 side of the liver [lobus hepatis dexter]. c and c show the little branches also sent off to the liver from the vena cava in addition to the two largest branches. I do not wish to say that it matters whether these branches and offshoots originating from the liver consti-tute the vena cava or whether they are distributed from the vena cava into the substance of the liver. d marks the part of the vena cava where it pass-es through the septum and puts forth branches to it.

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N THE FIFTH BOOK, when you study the organs peculiar to the fetus, you will learn that in the uterus it is wrapped and contained in three tunics or wrappings5 (see each of the tables in fig. 30, Bk. V). The Greeks call the

outermost of these the χωρίον,6 the Latins secundina, secun-dae,7 and sometimes also loculi,8 like the uterus itself. When an infant is carried in the uterus, the ends of veins and arteries (n, y in fig. 25, Bk. V)9 extending to the fundus of the uterus end in this outer wrapping and turn, as it were, into new veins and arteries which are distributed by a very numerous series of branches into it [placenta].

HoW THe umBiLic aL Vein a nd arTeries oriGinaTe

These veins and arteries are gradually collected from a nearly infinite series of branches and become fewer as they join together – veins always united with veins, and arteries with arteries. From these branches joining each other, larger and fewer are in turn formed, until all the veins end in two veins, and the arteries in two arteries. The veins and arteries (N in fig. 30, Bk. V)10 gathered in this manner from the secundines penetrate the remaining two tunics11 that wrap the fetus; these tunics also receive small branches that run out from the veins through their membranous body.

1 This chapter was completely re-written for the 1555 edition. See Appendix.

2 Obliterated soon after birth. The left branch of the umbilical vein becomes the ligamentum teres or round ligament of the liver, since the umbilical vein no longer receives blood after the umbilical cord is severed. The right branch atrophies early in embryonic life and disappears.

3 According to Saunders and O’Malley (1973, p. 174), the illustra-tion of the annular placenta in the 1543 edition (fig. 30, Bk. V) is that of a dog. This was corrected with new drawings in the second edi-tion.

4 In fig. 12, Bk. V, M shows “[the sec-tion] of the liver into which the vein feeding the fetus is first inserted.” This vein, actually the round ligament of the liver (l. teres hepatis), is labeled D in fig. 20, Bk. V.

5 Vesalius’ three wrappings or mem-branes are: (1) the placenta (a feto-maternal organ; Vesalius is refer-ring to the decidua basalis or maternal portion of the placenta); (2) the smooth chorion plate; and (3) the amnion (forming the amni-otic sac containing the amniotic fluid).

6 Sic for χόριον, e.g. in Galen, De usu partium 4.224.16: “There is a thin membrane called the amnion,

which is placed all around the fetus and receives from it some-thing like sweat. Outside this lies another, thinner one which they call the allantois, and this is con-nected by a passage with the blad-der of the fetus and collected within itself something like urine from the fetus up until birth. Round about these is placed the chorion, lining the whole inside of the uterus, which consequently never comes in contact with what lies beneath, and it is by means of this chorion that the fetus is attached to the mother.” (4.224.8–18; tr. May, 1968, p. 661, who points out in n. 10 that Galen’s descrip-tion is of some ruminant such as a

goat). In a similar description of these membranes (De anatomicis administrationibus 12.4; tr. Duck-worth, 1962, p. 116), Galen says these membranes are usually dis-sected in goats.

7 Cf. English “secundines,” from late Lat. secundinae, classical Lat. secundae, for the placenta or after-birth.

8 A Latinization of the erroneous diminutive χωρίον or “little place.”

9 Where n = arteria/vena ovarica and y = a./v. uterina.

10 The two umbilical arteries and the umbilical vein.

11 Amnion and chorion.

O n t h e U M b i l i c a l V e i n 1

Drawing of the bare umbilical vein, showing the part that is visible in children.2 Here a marks the part of the vein that faces the umbilicus, and b the place where it is inserted into the liver. c and D represent its approximate distribution in the substance of the liver. From here, the figures of the fifth book that are most relevant should be studied, in particular the thirtieth, which shows the wrappings of the fetus together with the fetus itself in four drawings.3 The second figure in that book shows the portion of the navel [e] remaining after a process of dissection, in addition to portions of the umbilical vein [K], arteries [l], and the urinary tract [M] dedicated to removing urine from the fetus. Other figures in the same book illustrate the insertion of the umbilical vein into the liver, specifically the twelfth and twentieth.4

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cour se oF THe umBiLic aL Vein

When the veins have run as far as the umbilicus, they quickly join into a single vein [ligamentum teres hepatis] (F in fig.  2, Bk. V); often, in fact, only a single vein [v. umbilicalis] is seen as soon as it leaves the secundines. it enters the umbilicus and attaches to the peritoneum; as it climbs upward, it [ligamentum teres hepatis] is inserted (G in fig. 2, Bk. V, M in fig. 12, D in fig. 20) into the open fissure [f. ligamenti teretis] in the liver which in humans is on the front of the liver to the right of the pointed cartilage [processus xiphoideus] and receives this umbilical vein through an opening or passage [incisura ligamenti teretis hepatis], bringing it down through the substance of the liver toward the hollow part of the liver (D toward G in fig. 20, Bk. V), not far from the beginning of the stem of the portal vein (I in the same figure). This should be closely watched during dissection: if you casually look at the first entry of the vein into the liver, you might think it is going in halfway between the convex and the concave parts of the liver, and you will not have a correct idea of this opening in humans (who alone have this feature). in many animals, such as puppies, one or another branch sometimes extends into the center of the mesentery (L L in fig. 10, Bk. V) [radix mesenterii] from this vein (F in fig.  2, Bk. V) before it reaches the liver. i would like this to be closely noted, because there are places in Galen’s book De foetuum forma-tione where he surmises that the liver is formed prior to the heart from the course of this vein.12

THe cour se oF THe arTeries

The arteries (ρ in the figure for ch. 12 [arteria umbilicalis]; K, L in fig.  2, Bk. V) [ligamentum umbilicale mediale] inserted in the umbilicus and running downward at the sides of the fundus of the bladder (N in fig. 2, Bk. V) are connected to the branches (between ξ and ς in the figure

for ch. 12) [arteria iliaca interna] of the great artery [pars abdominalis aortae] after its principal division above the sacrum. The arteries entering the umbilicus join the branches of the great artery that descend through the foramina of the pubic bones into the leg, as we shall explain.

FuncTion oF THe umBiLic aL Vein a nd arTeries

The fetus is nourished by the umbilical vein, and its innate heat13 is restored by the arteries. When a baby is born, these vessels, together with the passage (M in fig. 2, Bk. V)14 by which its urine from the bladder is removed between the innermost and the second wrapping of the fetus (between O O [chorion] and M M [amnion] in table 3, fig. 30, Bk. V), are severed [chorda umbilicalis] (S in table 4, fig. 30, Bk. V) close to the belly by midwives; animals break off the wrap-pings with their teeth and usually swallow them. What still remains of these vessels in the body dries up over time and becomes quite membranous and ropelike as it loses its cav-ity. You will hear at length in the fifth book, where i shall describe the dissection of the organs of nutrition and gen-eration, by what procedure of dissection you may observe these parts not only in the anatomy of fetuses but also in the old. it has been my wish here to record what the umbil-ical vein looks like in mature adults, lest anyone think we have passed over this matter. so it is that the vein extends from the umbilicus to the liver and, as we have said, is inserted in the liver. in babies of some age, all of these parts appear dry, somewhat sinewy, and covered with a good deal of fat, while in fetuses they are no different from other veins. now it is time to describe the distribution of the great artery [aorta] (see the figure for ch. 12). i shall inter-rupt my account of the arterial vein [arteria pulmonalis] (fig. 1, ch. 15) until it is possible at the same time to explain the venous artery [vena pulmonalis] (fig. 2, ch. 15) fully. it is worth the trouble to give a combined account of both.

12 See De foetuum formatione 4.667.6ff.: “What, then, will fix the limit of the first period [of fetal development], during which the fetus does not as yet need a heart? It seems to me that this is the time before the whole division of the veins in the liver has been com-pleted. … For as soon as the vein from the umbilicus has penetrated

to the space within the skin of the fetus, it divides into two; … then, when each of these veins like a branch has given off other veins, and these still others, which give rise to more until both divisions terminate in certain extremities, the characteristic substance of the liver … grows round about and fills up the spaces between the divi-

sions like a cushion. And so the outgrowths of the lower vein are made in the concave parts of the viscus by which it clasps the right side of the stomach, and those from the upper vein in the convex part where it touches the dia-phragm.” (tr. May, 1968, p. 60).

13 Insitus calor, Galen’s ἕμφυτον θέρμον, gen. ἐμφύτου θερμασίας,

the vital substance concentrated in the heart and delivered by the arteries, on which see May, 1968, pp. 50ff. The conception is Hippo-cratic (Aphorisms 1.14).

14 In the fetus, M is the urachus; in the postpartum human, M becomes the ligamentum umbili-cale medianum (chorda urachi).

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T H E F A B R I C

O F T H E H U M A N B O D YCOMPLE TE VIE W

OF THE VEINS AND ARTERIE S

o Beginning of the unpaired vein [v. azy-gos]; its distribution is seen on the back of the present figure.8

p Fork in the vena cava [v. cava superior] at the throat. At both sides [venae bra-chiocephalicae] of p appear the begin-nings of veins [v. thoracica interna] be-longing to the pectoral bone [sternum], running off to the region of the umbili-cus. One of these veins9 – together with its companion artery [a. subclavia],

*, q. marked * – is labeled q on one side.10

r Beginning of the vein [v. intercostalis suprema] going to the intervalsbetween several upper ribs.

Vein [v. vertebralis] going to the skull through the transverse processes of the cervical vertebrae, and taken into the second sinus of the hard membrane [dura mater] with its companion artery.

t. t. The first sinus is marked t t [sinus trans-u. u. versus dexter], the second u u [sinus x. x. transversus sinister], the third x x [sinus

sagittalis superior], the beginning of the y. fourth y [sinus rectus].z z Vein [v. subclavia]11 to the armpit; on the

left side, it puts forth the humeral [ce-α. α. phalic] vein marked α α. On the right

side, its beginning comes here from the outer jugular [vena jugularis externa].

β, γ The truncated offshoots [vena thora-coacromialis, v. subscapularis] here are the ones that are distributed from the vein that passes to the armpit; they go the front, back, and sides of the thorax.

δ Inner jugular vein.12ε Division of the inner jugular into two

veins, one of which passes to the sec-ond sinus of the hard membrane, the other to the left side of the hard mem-brane.

ζ Outer jugular vein.η Distribution of the outer [external] jug-

ular vein at the throat. The portion run-ning off behind the ears to the occiput

θ. is marked θ [vena occipitalis], the part ι. to the temple and the vertex is ι [vena

temporalis superficialis], that to the face κ. and forehead is κ [vena facialis], that to

the second sinus of the hard membrane λ, μ. is λ [vena meningea media?]. μ identi-

fies two branches of the outer jugular, one of which enters the skull through the eighth bone [os ethmoidale, lamina cribrosa] of the head, and the other through the foramen for the second pair of cerebral nerves [n. oculomoto-rius].

ν Several characters that follow are placed on the right side, marking por-tions of the sleep artery [a. carotisexterna]. Here, ν identifies the portion [arteria carotis interna dextra] going to the skull after putting forth the branch distributed with the outer jugular to the face, temple, and behind the ear.

ξ Branch of the sleep artery going to the first sinus [s. transversus dexter] of the hard membrane.

ο Main portion of the sleep artery[a. carotis interna] entering the skull through its own foramen [canaliscaroticus].

π [ϖ] Branch extending toward the nasal cav-ity.

ρ Branch running into the right side of the hard membrane.

ς, τ Principal branches of the sleep artery, which are wrongly believed to form the reticular plexus.13

υ Branch [arteria ophthalmica] going to the eyes.14

ϕ Branch going to the thin membrane wrapped around the base of the cere-brum.

χ Network [plexus choroideus ventriculi lateralis] that we compare to the outer wrapping of the fetus.

ψ Right nerve of the sixth pair of cerebral nerves,15 cut off at the point where it is brought down along the side of the lar-ynx.

ω ω Right recurrent nerve [n. laryngeusrecurrens dexter].

1 Left trunk of the sixth pair of cerebral nerves.16

2 2 Left recurrent nerve.3 Small nerve going to the base of the

heart.174 Vein [v. transversa cervicis] going to the

back of the neck and the occiput.5 Vein [v. suprascapularis] to the back of

the scapula. Although hereafter we do not mark the artery separately, it is readily apparent from the drawing which vein has a companion artery run-ning alongside.

6 Vein [v. thoracoacromialis] to the skin covering the top of the shoulder.

8 Sic in both editions. The supple-mentary figure referred to (the 1st of eight) was printed on an unnumbered sheet attached to the present foldout page with the intention that it could be cut out and attached to the large foldout. The technique of layering paper details onto (or beneath) anatomi-cal illustrations developed in the work of subsequent anatomists such as Johann Remmelin (1583–

1632), whose Catoptrum microcos-micum (1613, 1619) used as many as 15 successive layers to reveal superficial and deep structures of muscles, bones, and viscera. See Gutierrez (2004).

9 Although the letter q is placed on the v. brachiocephalica, Vesalius probably means the v. subclavia.

10 Though the letter q is seen in the main foldout figure, the vein, the artery, and the asterisk appear only in suppl. fig. 2.

11 Which becomes v. axillaris in the armpit, fossa axillaris. The 1555 edi-tion adds that “the drawing match-es Galen’s opinion more than it does the truth.”

12 Illustrated as unrealistically nar-row in proportion to the external jugular vein.

13 The 1555 edition omits the relative clause.

14 1555: “and meeting of the principal branches.”

15 Vesalius’ 6th pair of cranial nerves is composed of modern cranial nerves IX, X, and XI; here, the nerve designated ψ is n. vagus dexter.

16 N. vagus sinister (see preceding note).

17 Possibly a cardiac branch of the left vagus nerve.

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