| XXX | (249) | XXX |
249 Part V. A N A T O M Y. intercoftal nerve, according to the common defcriphaving in its paflage thither a connexion with the fixth tion
- or, according to other authors, this nerve comes
pair. It is afterwards diftributed to the ball of the eye up from the great ganglion of the intercoftal, to be joined with the third; to the nofe, along with the olfactory, to the fixth here. which the branch of the fifth that paffes through the foraSeventh Pair comes out from the lateral part men orbitarium internum joins, as was already mention- ofThe procefs behind where the medullary proed in the defcription of the firfl: pair. This ophthalmic cefstheof annular the cerebellum are joined to that tuber; and each branch likewife fupplies the parts .at the internal canthus being accompanied with a larger artery than moft other of the orbit, the glandula lacrymalis, fat, membranes, nerves, enters the internal auditorius, where the mufcles, and teguments of the eye-lids; its longed far- two large bundles of fibres,meatus of which it appeared to theft extended branch pafling through the foramen fupperci- confift within the fkull, foon feparate from each other; liare of the os frontis, to be diftributed to the forehead. one of them entering by feveral fmajl holes into the veftiThe fecond branch of the fifth pair of nerves may be and femicircular canals, is ftretched on this called Maxillaris Superior, from its ferving princi- ble, cochlea, camera of the ear in a very foft pulpy fubftance ; pally the parts of the upper jaw. It goes out at the inner round hole of the fphenoid bone, and fends immediately and being never feen in the form of a firm cord, fuch as one branch into the channel on the top of the antrum maxil- the other parcel of this and moft other nerves become, is Portio Mollis of the auditory nerve. lare ; the membrane of which and the upper teeth are fup- called plied by it in its paffage. As this branch is afiout to go out The other part of this feventh pair paffes through Gaat the foramen orbitarium externum, it fends a nerve len’s foramen csecum, or Fallopius’s aquasdudt, in its through the fubftance of the os maxillare to come out at crooked paffage by the'fide of the tympanum ; in which pafSteno’s dudl, to be diftributed to the fore-part of the palate ; fage, a nerve fent from the lingual branch of the inferior and what remains of it efcaping at the external orbitar maxillary nerve, along the outfide of the tuba Euftahole, divides into a great many branches, that fupply the ichiana, and crofs the cavity of the tympanum, where it cheek, upper lip, and noftril. The next eonfiderable has the name of chorda tympani, is commonly faid to be branch of the fuperior maxillary nerve, after giving joined, to it. The very acute angle which this nerve branches w'hich are reflefted through the fixth hole of the makes with the fifth, or the fudden violent refledtion it fphenoid bone, to join the intercoftal where it is palling would fuffer on the fuppofition of its coming from the through the Ikull with the carotid artery, and theportio fifth to the feventh, appears unufual; whereas, if we dura of fhe feventh pair, as it pafles through the os pe- fuppofe that it comes from the feventh to the fifth, its trofum, is fent into the nofe by the hole common to the courfe would be more in the ordinary way, arid the chorpalate ajid fphenoidal bone; and the remaining part of da tympani would be efteemed a branch of the feventh pair going to join the fifth, the fize of which is increathis nerve runs in the palato-maxillaris canal, giving off fed by this acquifition. This fmaller bundle of the branches to the temples and pterygoid 'mufcles, and feventh gives branches to the mufcles of the malleus, and comes at laft into the palate to be loft. - The third or Maxillaris Inferior branch of the to the dura'mater, while it paffes through the bony fifth pair going out at the oval hole of the fphenoid bone, crooked canal,' and at laft; comes out in a firm chord ferves the mufcles of the lower jaw, and the mufcles fi- named Portio Dura, at the end of this canal, betuated between the os hyoides and jaw: All the falivary tween the ftyloid and maftoid procefles of the temporal glands, the amygdalae, and the external ear, have bone, giving immediately filaments to the little oblique branches from it: It has a large branch loft in the tongue, mufcles of the head, and tothofe that rife from the ftyloid and fends another through the canal in the fubftance of procefs. It then pierces through the parotid gland, and the lower jaw to ferve all the teeth there, and to come divides into a great many branches, which are difperfe'd out at the hole in the fore-part of the jaw, to be loft in in the mufcles and teguments that cover all the fide cf the upper part of the neck, the whole face and cranium, as the chin and under lip. The Sixth Pa’ir, which is the fmalleft except the far back as the temples, including a confiderable part of fourth, rifes from the fore-part of the corpora pyrami- the external ear. dalia; and each entering the dura mater fome way behind The Eighth Pair of nerves rife from the lateral -•■•he pofterior clinoid procefs of the fpenoid bone, has a bafes of the corpora olivaria in difgregated fibres; and as long courfe below that membrane, and within the recep- they are entering the anterior internal part of the holes taculum at the fide of the fella turcica, where it is im- common to the os occipitis and temporum, each is joined merfed in the blood of the receptacle: It goes afterwards by a nerve which afcends within the dura rnater from the out at the foramen lacerum into the orbit, to ferve the tenth of the head, the firft, fecond and inferior cervical abduftor mufcle of the eye.—A defedt in this nerve may nerves : This every body know's has the name of the Nertherefore be one caufe of a ftrabifmus.— In the paffage vus Accessorius. When the twoget out of thelkull, of this nerve below the dura mater, it lies very conti- the accefforius feparates from the eighth, and, defendguousjtw the internal carotid artery, and to the ophthal- ing obliquely outwards, paffes through the fterno-maftoimic branch "of the fifth pair of nerves. At the place deus mufcle, to which it gives branches, and afterwards where tfm fixth pair is contiguous to the carotid, a nerve terminates in the trapezius and rhomboid mufcles of the either goes from each of them in an uncommon way, to fcapula. In this courfe it is generally more or, lefs joinwit, with the angle beyond where it rifes obtufe, to de- ed by the fecond cervical nerve. fcend with the artery, and to form the beginning of the The large Eighth Pair, foon after its exit, gives Vol. I. No. ii. 3 3 Rnerves
