The structure of the cartilages of the nose is essentially similar to that of the articular and other true cartilages, (cartilogines figu rate, Meckauer.) Their cells are numerous, very close set and large ; and next to each of their surfaces there are two or three layers of thin flattened cells, which give the borders of a section through the thickness of the cartilage a somewhat fibrous aspect. But the basis-sub stance is, in reality, entirely destitute of fibres.
The greater rigidity and firmness of the sep tum-cartilage is due to its greater thickness ; its minute structure is siinilar to that of the cartilages of the aim. The latter are easily flexible, but the pliancy of the sides of the nose does not depend on them alone, but in as great a degree on the tough fibro-cellular membrane in which they are imbedded. The combination of the two tissues is indeed admirably adapted to the purposes which are to be served. The cartilages are sufficiently rigid to give thc alw a definite form during rest ; and they are so elastic that, when the nostrils have been either compressed or expanded, they are restored to their natural position by the recoil Of the carti lages, without any muscular effort. If the vvhole side of the nose had been formed of cartilage, much stronger muscles would have been needed for the several movements of the nostrils; but, by the intervention of small por tions of fibro-cellular membrane, these move ments, whether mpid or long-sustained, are ef fected by some of the weakest muscles of•the body, and with a scarcely perceptible effort of the will. The arrangement is somewhat ana logous to that in which strength and flexibility are combined by strong scales or plates being set on the pliant substance of the skin of va rious animals.
The muscles of the nose, like those of the rest of the face, are but ill-defined, and anatomists have differed much in both the description and the enumeration of them. The following, ac count is dravvn from the results of several dis sections purposely made, and compared with the descriptions of Santorini,* Arnold,-l Theile,t and others, who have examined the matter for themselves.
1. Pyramidulis, (Casserius proeerus, San torini; frouto-nasal, Chaussier.) This (c,Jig. 903) cannot be strictly allied a separate muscle of the nose, and it is described with the front alis by IlaIler, Theile, and many others. It consists of those fibres of the median portion of the frontalis muscle which descend in a fasciculus over the upper part of the nose.
They terminate in the cellular tissue covering the superior carulage, and, through its medium, they are attached to the cartilage itself, and to the adjacent border of the nasal bone; many of them also are continued onwards and mingled with the upper fibres of the triangularis nasi (e), with whose aponeurosis, moreover, theirs is always continuous. At their inner margin these fasciculi are in contact above, but they diverge below as they pass over the surface of the nasal bones, and they thus assume that appearance of two distinct slender triangular slips of muscle which led Santorini to give them a distinct name, though they have not that distinct origin which he assigns to them.
l'he pyramidales do not appear to have the power of acting alone. When the rest of the frontalis contracts, and, by drawing down the scalp, wrinkles the skin of the forehead. they also act, raising and tightening the skin over the upper part of the bridge of the nose. They produce the same effect when the brows are dmwn up, as in surprise.
2. Levaior labii superioris alcrque nasi, (Al binus, Weber, &c.; pyramidalis, Santorini ; oblique, ou lateral, Winslow ; elevateur com mun, Bichat, Bourgery, &c.) This, (d,d, .fig. 403,) which is the largest and strongest of the muscles of the nose, arises, internally, by a narrow slip of fibres from the upper and outer part of the ascending process of the superior maxillary bone, and, externally, by a broader origin from below the inner part of the lower border of the orbit. Its origins are covered by the orbicularis palpebrarum, and from them its fibres proceed downwards and diverge. About two-thirds of them pass to the outer part of the upper lip, mingling with the fibres of the orbicularis oris (i) and levator labii proprius, and inserted for the most part in the skin ; the remainder go downwards and a little forwards over the posterior third of the ala of the nose. Of these last, some are attached more or less intimately to the posterior parts of the inferior cartilage and the membrane in which it is im bedded ; many more terminate in the skin over the lower part of the ala, and are there mingled with fibres which run in various directions, but usually form a complete layer of muscular fits eiculi beneath the skin of the outer border of the nostril.