Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 12 On The Foramina of the Head and the Upper Maxilla

Channels made to drain phlegm from the brain

M 3 Pocket [fossa hypophysialis, sella turcica] cut in the cuneiform bone containing a small gland [glandula pituitaria] into which the phlegm running down from the brain flows, which Galen declared then flows through the bone forming this pocket into the palate, 46 claiming that it is perforated with holes like a seive or sponge and the phlegm strains through it. 47 Were it not that a certain piety towards Galen restrains me, I would show that this opinion is no less than totally untrue. This part of the bone, which is the middle of the cuneiform, is never perforated like a sponge, much less like a seive, being made there of a solid and continuous scale containing within many of those large cavities [sinus sphenoidalis] which we illustrated in the eighth figure of the sixth Chapter, which can be seen only if the bone is first broken. Phlegm in no way descends through such foramina (since there are none) in the cuneiform bone. 48 Rather, two ducts, carved out as cavities [sulcus caroticus], run down on each side from the pocket marked M; 49

Since this figure which belongs in the seventh book is not useless for more accurately understanding the present passage, I have added it here, indicating by A the small gland [glandula pituitaria] into which phlegm runs. B denotes the basin [infundibulum] made from the thin membrane of the brain. C, D, E, and F are the four ductlike passages draining phlegm from the gland.

the anterior duct heads to the second foramen [fissura orbitalis superior], marked G, which we described in the root of the eye socket, carrying phlegm to the eye socket and thence through the foramina [fossa sacci lacrimalis] marked C and F. The posterior cavity extends downward to a rough and uneven foramen or rather fissure [foramen lacerum], through which the phlegm flows into the mouth or rather the palate and air also goes to the cranium during respiration.
N[ 2 , 3 ] This fissure [foramen lacerum], common to the temporal bone and the occiput, 50 we have marked N on the left side of the second figure and on the right side of the third. These ducts or depressions do not present themselves to view so readily in the third figure (since they do not seem quite hollow);
O P[ 3 ] but we have marked the anterior cavity O and the posterior P in the same figure so that with the help of these letters you may locate the area of these depressions more quickly in actual skulls. To the processes that appear in a circle around the pocket marked M 51 [fossa hypophysialis, sella turcica], the hard membrane [dura mater] of the brain (figure 15, Book 7) is very firmly attached and is as it were supported in that area where it recedes from the base of the skull and has beneath it the greater branches of the sleep arteries [a. carotis interna] and the passages recently mentioned that carry phlegm downward. 52
Q 2 , 3 At the side of the uneven, rough fissure or foramen marked N, more toward the anterior, there is cut in the cuneiform bone another foramen [foramen ovale] which is smooth and not exactly round, but resembles a circle slightly squeezed on both sides into an oblong. It was fitting for a foramen with this shape to be introduced because it had to carry two rounded bodies connected to each other by membranes. It provides passage to the thicker and principal root [n. mandibularis] of the third pair of cerebral nerves [n. trigeminus] root together with the fourth pair [nn. palatini, n. maxillaris] (I and K in fig. 14, Bk. 7; M [n. mandibularis] and Z [nn. palatini] in fig. 2, ch. 2, Bk. 4).

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R 2 , 3 Again at the outer side of the foramen marked Q, there is seen in the cuneiform bone another foramen [f. spinosum], much smaller and perfectly round, through which a portion [vena meningea media] of the interior jugular vein (F in the fig. in ch. 14, Bk. 3) moves away from the sleep artery and goes up into the skull. Sometimes a small foramen [f. venosum] 53 is observed near the inner side of the foramen [f. ovale] that carries the two pairs of nerves [n. trigeminus] just mentioned, made for a small branch [v. emissaria] of the same vein. But it is rarely seen in one side of the skull, and much more rarely still on both sides.
S[ 2 , 3 ] Nevertheless, we have included the foramen here also, on the left side (because among the other skulls there was one with this foramen, that seemed a better specimen than all the others) 54 ; we have labeled it S [f. venosum] in the second and third figures.
T T[ 3 , 4 ] From this foramen, depressions 55 that correspond to the arch of the divided vein [vv. meningeae mediae] ascend 56 through the interior of the skull, hollowed out so that the bone of the skull will not press and constrict the depressions (D, D in fig. 1, Bk. 7) as they run like veins in the hard cerebral membrane. We have labeled these depressions in the skull T, T several times in the third and fourth figures. 57
V 2 This foramen [tuba auditoria, pars ossea], visible on the outside 58 of the base of the skull, cannot readily be seen. From here it is extended obliquely to the outside into the cavity carved in the temporal bone for the organ of hearing (the main portion of the fig. in ch. 8), and ends. I shall therefore put in a drawing a little later with several foramina of the organ of hearing 59 . The foramen is made to extend a passage for a small branch (b in fig. 2, ch. 2, Bk. 4) of the fifth pair [n. facialis] of cerebral nerves that runs out from the cavity of the organ of hearing by this route to the muscles that raise the lower maxilla. In addition, a branch of the inner jugular (n in the fig. for ch. 14, Bk. 3) goes to the organ of hearing through this foramen, and air as well is carried through it into the chamber [cavitas tympanica] of the temporal bone belonging to the organ of hearing. You will easily perceive this if you take air into your mouth and try as it were to expel it through your ears: you will hear the sound of winds in your ears, or a sound not unlike that of whirlpools.
X 2 , 3 A conspicuous foramen [canalis caroticus], hollowed out for the greater branch of the sleep artery [a. carotis interna] (L in the fig. for ch. 14, Bk. 3) as it enters the skull; it does not pierce the skull at a right angle, but is carved in an elongated course from the rear obliquely inward toward the front of the temporal bone. The part of the bone [os temporale, apex partis petrosae] penetrated by this foramen, where it faces downward toward the throat and is labeled œ in the second figure, looks rough and uneven like pumice. X [canalis caroticus], placed in the second and third figures, shows the course of this foramen, as does the illustration which we have added at this point,

This figure, with foramina marked X and Y, helps to illustrate them better. It includes the courses of the foramina on each side, aligned as they are seen when followed by animal bristles inserted in the skull or by strands of lead wire. Both X's mark the left foramen [canalis caroticus] made for the largest branch of the left sleep artery, while both Y's show the foramen [canalis pterygoideus?] cut for the small branch [?] of the sleep artery that runs out into the nasal cavity.

where X and Y do not have the same location relative to each other as they to in the larger figures. 60 Nature fashioned 61 this duct [canalis caroticus] running obliquely over a long course in the bone for the longer and more oblique progress of the sleep artery, no doubt so that the vital spirit would be more perfectly prepared for the brain by this roundabout route of the duct. For this reason I am especially suprised at Galen, who missed this large foramen (among many others) as not worth considering in passing, 62 and who left it written in his book about the dissection of an ape’s veins and arteries 63 that the sleep arteries enter the skull through the foramen marked Q [f. ovale in this chapter], used by the third and fourth pairs of cerebral nerves. 64 And just as in that book he inspected neither dogs not apes concerning this foramen and passed falsehoods on to posterity, so also it is no surprise that in his imagination he made up the amazing reticular plexus in humans also, and passed on to memory a series of cerebral vessels that is not everywhere factual. 65
Y 3 From the region of the end of the foramen just mentioned, marked X [canalis caroticus], which faces the cavity of the skull, another foramen 66 [f. lacerum] is begun, extending straight forward into the nasal cavity like an elongated passage, 67 providing a route for a branch 68 (s, t in the fig. for ch. 14, Bk. 3) of the artery which extends as far as the nostrils from the larger part of the sleep artery [a. carotis interna] where it enters the skull, there giving out a noticeable pulse along with other arterial twigs reaching that way. You will find that this foramen is peculiar to the cuneiform bone.
a 2 , 3 Path of the fifth pair of cerebral nerves [n. facialis et n. vestibulocochlearis] (a in fig. 2, ch. 2, Bk. 4), or auditory passage [meatus acusticus externus osseus], whose beginning in the inner space of the skull is marked a in the third figure.

I have added this rough drawing [1543 version above, 1555 below] to have in view the courses of the foramina marked V [tuba auditoria, pars ossea], a, and b. In a rough and sketchy way, the auditory meatus is marked a; V is the foramen marked V above; b [foramen stylomastoideum] will soon be explained under the letter b. This drawing refers to the left side.

The letter a in the second figure marks its exterior portion [meatus acusticus externus], which begins from the ear, more or less resembles the auricle, and appears rough. 69 Although this passage is rather large and hollow, it is found to be so twisted, winding, and richly variable that it very rarely accepts the insertion of a bristle. That one does not pass through is less because of the twists and turns of the passage than it is because near the ear [cavitas tympanica] and later where it turns toward the brain it ends up narrower than in the middle (i in the figure for chapter 8, book 1) where it appears quite large and wide. 70 But Aristotle is not at all to be heeded when he claims that no passage

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runs from the ear to the brain. “But a passage does run to the roof of the mouth,” 71 he says, “and a vein runs to it from the brain.” 72 The auditory meatus [m. acusticus internus] extends to the skull cavity and also admits a vein (n in the fig. for ch. 14, Bk. 3): 73 it does not bring it down 74 from the brain, but it takes the vein to the organ of hearing from the inner jugular as it enters the skull, 75 and as we earlier stated it provides a path to the small branch [n. vestibulocochlearis] of the fifth pair of cerebral nerves. Furthermore, if you introduce a bristle into the auditory passage from the outside and push it in at a slightly forward angle, you will see it borne much more easily into the foramen marked V [tuba auditoria, pars ossea] than into the space of the skull.
b 2 Foramen [f. stylomastoideum] beginning from the middle of the space belonging to the organ of hearing and extending backward from there. Because of bends and labyrinths, and because it does not reach the inner part of the skull, it will not let a bristle pass through. It is provided for a small branch [n. facialis] (c in fig. 2, ch. 2, Bk. 4) of a nerve of the fifth pair; since Nature wished it to harden, she very cleverly brought this branch through a winding foramen of the hardest and driest bone [os temporale, pars petrosa]. It is called by all professors of dissection tuflo/n, the blind [caecum] or one-eyed foramen, not because the passage is not real or penetrable, but because it does not admit a bristle or lead wire 76 into the space belonging to the organ of hearing. This foramen is located above the root of the mammillary process [p. mastoideus] in wolves and dogs, where it is much larger and more spacious than in humans. Some, perhaps, call the foramen [tuba auditoria, pars ossea] extending forward out of the auditory meatus [auris media], marked V, “blind.” However that may be, they know nothing about this foramen V or the one marked b. But so far I have found in no author even a single foramen described as fits the subject, though the exploration of foramina is most rewarding and they are evidence of Nature’s supreme diligence. 77
c 2 , 3 Foramen [f. jugulare] common to the occipital and temporal bones, carved out for the sixth pair 78 of cerebral nerves (N in fig. 9, Bk. 7), the greater branch of the inner jugular vein (C and then I in the fig. for ch. 14, Bk. 3), 79 and the lesser branch of the sleep artery [a. carotis interna].

We have made a separate drawing of the foramen described here, marking the inner part q and the outer i.

Because the organs passing through here are very large, it is large in accordance with the shape of the bodies passing through. For it is not perfectly circular but more or less doubled and turned in upon itself; one part (which is inner) is made for the nerve 80 exiting the skull in a more or less forward direction; the other (which is outer) serves the [internal jugular] vein and the [internal carotid] artery entering the skull in a posterior direction.
d 2 , 3 Foramen [canalis hypoglossi] in the occipital bone incised for a nerve [n. hypoglossus] (O in fig. 9, Bk. 7 and n in fig. 2, ch. 2, Bk. 4) of the seventh pair of cerebral nerves; it is round, but has a long and slanting course. It is carried downward 81 from a posterior and inner point in the skull so that the nerve of the seventh pair would pass through this foramen and be joined to the sixth pair more quickly, and so that at the same time both would stick together and descend safely. 82
e 2 , 3 A single foramen [f. magnum], easily the largest of them all, is introduced into the occipital bone for the sake of the dorsal medulla [m. spinalis] (H in fig. 9, Bk. 7) that takes its origin from the brain.
f 2 A not especially large foramen [canalis condylaris], which begins from the outer part of the skull out of the posterior part of the head’s occipital bone (l in fig. 5, ch. 6) which is articulated to the first cervical vertebra, and goes by a long course through the bone into the inside of the skull, ending in the higher part of the foramen marked d [canalis hypoglossi] belonging to the seventh pair [n. hypoglossus] of cerebral nerves. This is hollowed out for the vein [vv. columnae vertebralis] and artery [a. vertebralis] (D and K of the fig. for ch. 14, Bk. 3) climbing upward through the transverse processes of the neck vertebrae. In certain skulls, you will find this foramen is missing on one side, and sometimes even on both; in such cases its function is performed by the foramen of the seventh pair of cerebral nerves, marked d, which then does not appear exactly round but oblong, suitable for transmitting the nerve together with the vein and the artery. 83
g 2 , 3 This foramen [f. mastoideum] is carved out in the temporal bone near the posterior region of the mammillary process [pars petrosa, processus mastoideus], by the side of the lambdoid suture (C in figs. 3, 4, 5, ch. 6); entering the skull transversely, it furnishes a path to a branch 84 (E in the fig. for ch. 14, Bk. 3) of the outer jugular vein that goes into the skull at this point. I have occasionally noticed that this foramen is missing, sometimes on one side, sometimes on both.

Book One -- The things that sustain and support the entire body, and what braces and attaches them all. [the bones and the ligaments that interconnect them] | Chapter 12 On The Foramina of the Head and the Upper Maxilla